RC India

Hi All,

I have recently purchase Turnigy9x and after 4th or 5th time during on process,
I turn on it and hear some burst noice (very low), and then smell, and I switched off that radio instantly

So I open it and found one component on board is burned....

can anyone help me ???

Hi,

The exact same thing happened to me on my Flysky th9x which is the same as turnigy, although i didn't hear a burst of any sort.

I sent mine to RCBazaar for repair as i purchased it from then.

The part that is burnt is the capacitor. You can find more information in the links below.

http://www.rcgroups.com/forums/showpost.php?p=16880335&postcount=11
http://www.rcgroups.com/forums/showpost.php?p=17595400&postcount=4589
http://www.rcgroups.com/forums/showpost.php?p=19956229&postcount=5

Thanks karthik,

Nice to know that I am not the only one,
So is your radio is repaired by RCBazaar ??
Is it working properly after repair ?

do you know can tell me what is marked on you persent capacitor/registor value ??

The radio has not been repaired yet, as the availability of parts locally is the issue.

The part no is "10 20U" for the capacitor.

ok, is it the same capacitor, shown in my radio pic ? or you  have burnt another,

and following link show, person is repairing it with help of 4 electronics component
http://www.rcgroups.com/forums/showthread.php?t=1415356#post19956229

1x This Cap (Part # 478-1682-1-ND)
1x This VR (Part # LM78L05ACZNS-ND)
1x This VR (Part # 296-11118-1-ND)
1x This VR (Part # NJM78M05FA-ND)

a bit confused, i can do soldering but I am not electronics guy in reading capacitors etc...

The capacitor burnt in my radio is the same one as yours.

The other 3 parts that are mentioned are IC's which are with the capacitor and form the voltage regulator. The parts mentioned in the link are the ones he had to change but does not necessarliy mean the exact same ones are damaged in your radio too.

I would suggest you to visit your LHS or a known professional who is well versed with PCB's to identify any burnt or damaged parts by using proper instruments as superficially looking at the circuit will not help you.

Also, soldering a SMD based IC is a different art altogether. I would not suggest you trying it if this is the first time you are working on a PCB.

Please note that the exact part in your radio might be different from others as the internal hardware may have changed as per the needs of the manufacturer.

PS: Ironically I am an electronics engineer myself and have worked plenty on circuit boards but still sent mine to a professional as i dont have all the required equipment to work.  ;)

There are actually  only two components.

1. Electrolytic capacitor( Tantlum type) of 22 mfd 0f at least 16volts( this is a polar device having  a positive and - tive ends.)------the yellow one on your pcb.( any electrolytic capacitor will do well if tantlum is not found)
2. Voltage regulator 7805, the one used here is the low current type with an L, 78L05.-------the black thing with three legs on your pcb.

Both these components are surface mount type. If physical space permits normal type can be fitted also.

Both of these components are very easily available in Lajpat rai market in front of Red fort.( Approx Rs 50 for both)

Jitender

Thanks Jitender,

Lajpat Rai market is easily reachable from here, can you please provide me exact component name and pic(if possible) that will be great help for me

I suppose for second one I have to ask 7805 or 78L05 which is exactly component above to burnt component ??

I think I have burnt this component (electrolytic capacitor)
http://search.digikey.com/us/en/products/TAJB226K016RNJ/478-1682-1-ND/564714

Jitender, the 7805 is only one of the IC in the circuit.

The other two namely 6206A ( left side diagonally to the burnt cap) and J476 ( smaller one to the right of 6206A) are voltage regulators too and there is a possibility of these being damaged as well.

Please correct me if i am wrong.  ???

Am I understanding right ??

Please correct me ......

I want these component name correctly  :help:

Yes the link shows how it will look.

Ask for or write on paper----22mfd / 16v   tantalum SMD.

As you enter Bhagirath palace from Lajpatrai market side, there are only 2 streets/gates that you can enter through.
In the 1st street/gate ( fromm chandani chowk side) about 15 meters inside there is an electonics shop (a corner shop with two sides open) which sells only components. Both of these will be avalable .

However these are very common components and will be easily avalable at many other shops. ( they usuly do not bother to entertain customers asking for one or two pieces)

The best place to get these components replaced is a mobile repair shop. the will have the components or will get them and have all the equipment to desolder and solder SMD components.

Jitender

Thanks Jitender,

So Do I need to replace only that brunt component..........( 22mfd / 16v   tantalum SMD ) if that component is comman then here is a shop of electronics component, who deal in retail.
or do u know any shop in Bhagirath Place who deal in these component and also deal in 1-2 peice, any shop no ??

the 476J cap seems ok. but can not say as pic is of low resolution.

Jitender

lets have closer look of PCB

most component name are clearly visible

(So Do I need to replace only that brunt component..........( 22mfd / 16v   tantalum SMD ) if that component is comman then here is a shop of electronics component, who deal in retail.
or do u know any shop in Bhagirath Place who deal in these component and also deal in 1-2 peice, any shop no ??)

Yes there are shops selling one or two pieces aso , the one i have mentioned in my earlier post is one.

Will get back to you latter now sleepy Good night.

Thanks Jitender and Karthik,

I'll find these component in morning and try to repair it my own, and will update here....

only if you know how to solder , then only try  to touch the tx inner circut otherwise you will damage the radio , sent you a pm  may be it will work for you ..

this happened to a fellow flyer here.. i m sure thts the same chip. did u reverse the polarity while connnecting battery ?? it happens generally becuz of that.

I visited electronics shop, for this component,
but no good luck,

but he said that it "CRISTAL" component, called it cristal...

thts an RF transistor. u cant get it locally here.. i struggled a lot finding the components for my hitec optic 6 which i burnt reversing the polarity.. imported some also but it was a vain. i decided to send it back to usa for repair.  and kept it aside cuz forshipping to n fro and repair would be a new hitec optic 6 for me. got another for myself.

Do any one know any one who can surely repair it ??
Sujith - ur radio cost is high to it deserve what u did, but mine is 59$ for new with Rx....haha

So my intension to repair it here locally.....

haha.. yeah..

Hello All,

After discussed with Jitender Sir, I have replaced that burnt component with another capacitor, and now my radio is beeping....

Beep partten is

Beeeeeep  Beep Beep  Beep Beep  Beep Beep

I am not sure, and suspecting it is beep for low battry, on volt meter my battry is showing 10.8V

can any tell me what is that beep ??????

Hi All,

I just upload that beep video, and here I see its not battry issue,

It is just switch error, so I went back to my Transmitter and put all switches in correct condition ......waaalaaaa

Its working................... :giggle: :giggle: :giggle:


I would like to Thanks all ppl who participate in this blog and special Thanks for Jitender Sir  :hatsoff: Who help me with his mindblowing knowledge and gave me lader to achive this moment  {:)}

I have repaired with help of my faulty DVD Player, Because I didnt got capacitor today, but after talk Jitender Sir, I came back home and start finding that value capacitor
and finally found one in my faulty DVD player power supply board. so I unpluge it from their and pluged it in my Transmitter,

Finally I used my multi nose soldring iron (dont know its exact name) and it did work well, now further testing is still pending so I'll do it and will update u soon....

Once Again.....Thanks to all and Jitender Sir  :salute:  {:)}  :thumbsup:  :thanks:

:thumbsup:

Do post some after surgery pictures ! :)

Sure Anwar Sir,

But due to low battry on mobile I have clicked only these pics but after that I start giving beep and was showing
Batt : 1.1 reason was Capacitor was not properlly connected to through the circuit,

after remove that burnt part, transmitter will able to on but with enoying beep, and show you Batt: 1.1

Total operation was, I have replaced Tantalum SMD with normal capacitor............(as discussed and suggested by Jitender Sir)

Tantalum SMD - 22mfd/16v
Normal Capacitor - 22uf/50v

This is pic with detail, what you have to do in case of this issue, and how to check.

Surely,

The difference is the ESR. there are electrolytic capacitors having 85 and 105 deg C. Choose 105 degree one. And in parallel, connect any 0.1uF of 0.22uF Capacitor for low effective ESR.

Possibly would work. And search for beep code.

I didnt understand sir, but now there is no beep issue.
and I have also checked is binding and is binding without any issue. i have checked its first 4ch and they are working fine...

Dear All,

I've read the entire mail but understand that you'll found the solution to the problem by repacing the right part but my question is Why did this Happen ? becuase all TX is Q TESTED & then sold to valauble customer like us ?

Is it because of bad dry soldering  ? or  due to high voltage to TX i,e  12.6V  continuosly operating for a long time or ?? pls try to find out the reason ,  this Thread can help another person  who buys a similar TX & Caution him to check his TX for any such problem .

I felt this thread is very important for Turngy tx User therefore asked this question & awaitng for replies.

pls also advise what to check in the TX for any such problem for eg Dry soldering etc.

regards Peter

i agree on peters point

There is no way to check  each individual component manufactured in millions and used in millions of gadgets  no level of QC practical to use. Even if each and every component going into a gadget can be checked and the the gadget using them in every single stage of manufacturing could be checked for any faults which is practically impossible, then even after passing the ultimate QC before release of the product for sale there is a chance of a component failing in operation. It happens to the unlucky person. If something COULD go wrong then it WOULD go wrong some time or other.  :) We just have to accept that.

Regards

point rao

Happy to here that
 "It's Working."

Thanks

yes kalyan , you will find most of these types of threads ending  with nothing..this is something good

Hi All,

Its all depend on Luck, Few People burn that component by worng polarity and few like mine burn it without any wrong thing, most important thing is "We should know solution of problem" then we cant consider those problem as a problem, but when we dont know solution of problem then this is big issue.

This is want we can do.....

Play............Break............Repair...........and Play Again.........Cheers !!!

Hi all,
like gbisht even i got my radio burnt. I tried just by replacing the capacitor, but could not get it started.After few more inspection, i found wiring track near the switch was burnt.Got it repaired, but still no response. So finally hunted for the ICs.
got 78L05 and replaced.
Now my radio starts, binds, but servo doesnt show any actions for stick movements..

And on display its showing " BAT:9.0 ", while the actual voltage of battery is 10.2.

I have attached the after surgery pictures.

Abhay : Nice to see that my past work is usefull for someone.

You dont seems new but still how u are binding your Rx ?

Put Bind Plug in BATT (first n last pin)
put ESC in any channel (3-ch is good)
and then bind

I hope this will solve the issue

Yes Gbisht,
I am doing the same:
let me describe my procedure:

1:plugging bind plug in last pin of Rx
2:plugging ESC wire in channel 3
3:plugging ESC to battery.

the red light starts blinking on Rx

4:swithing on tx while "bind range test" button on module already pressed.
tx gets swithed on, after a second or two, the red light on rx stops blinking and glows continously..

then i switch off my tx, then rx.
remove bind plug from rx and then try to use it like my other Mhz Radio systems....

but why i am worried is:
1:i am getting 9.0 v in display panel..
2:and does this tx also make a beep sound while swithing on? my doesnt make  :(

Abhay,

Put bind plug in slot where written BAT, instead of BIND, I suppose that is Second Ch from TOP.

Look,
As 9 volt displays that means the microcontroller is OK but a separate subroutine is executing and so reading the pot position and generating pulss is not possible. But RF section is OK that is why it binds smoothly. But Serial Data that goes to Tx is missing.

So, there is two option.
1. Either the voltage sensing circuit has changed/modified (with time/humid weather, change of capacitance/resistance value change).
or
2. The voltage itself is low.

So, think for the problem corresponding  to easiest solution  first.
The voltage itself low may be occured for loose connection or burnt wire/loose connector.
Check that first.
Again, use 8 dry-cell in series if it disappears. If yes, it may be other problem. If not, check all connections.

But if the circuit modified (for diode replacement or insertion) voltage drops and this type error displays.

have you introduced any diode in battery line for extra safety? Just short it and check.

Waiting for solution.

yes gbisht'
i tried on ch 9 also.. no response..

i still wonder why does the light stops blinging (and glows continuously) and rx gets bind, still servos not responding..

i even factory reset the tx..


@ kalyan sir, yes i've inserted a 1n4001 diode, to check any further reverse polarity..
ive attached the image also

regarding battery: i use a 8-cell nimh rechargeble battery pack (1000 mah) for my Tx

i am still worried about the "no beep" issue on switch on.

I think I missed something is tx only showing BAT 9.0 Only on display ??? no turnigy logo or any other information.
if yes then read my above thread again

As told earlier,
JUST SHORT THE DIODE AND CHECK AGAIN Please...

Hope failsafe mode would vanish.
If you want to keep diode, use LiPO insted LiFe battery or use low drop diode.
Possibly there is another in built diode inside which drops further. You may short that also insted of 4001.

Yes kalyan sir,
will short the diode in some time and check it..

@ gbisht , the screen is all normal with display. just now i have low battery on camera. will upload screen photo in a couple of hour..

Abhay

@ Kalyan sir,
I have eliminated diode. The voltage now it shows it 9.7 V, on actual voltage on battery being 10V. I think voltage problem is solved.

But Rx still not functions.But binds smoothly.
I am afraid about the buzzer too. Is there anything wrong with 6206A regulator also??

Why afraid ?
Just measure the in out voltage of the IC. If OK, then forgot about that.

Now, check the Joystick POT terminal Voltages with respect to ground. (Or Negative).
If all the terminal voltags are same, you have to check the POT common terminals (of various POTs) and the uncommon terminals. And the connected voltage supply block / component.

And check if the servos connected to Rx have stable position or uncontrollable. (If no signal is present, you can rotate servo arm and it will not return back. But if you cannot or returns back, It gets signal, but fixed one. In first case, Crystal may be damaged (But as display works, it depend on circuit diagram) and in second case, POT Data are constant (Or POT Supply voltage is missing).

Waiting for early recovery.

Datasheet :
http://www.infinwin.com/files/LN6206.pdf
Thanks

i hope this thread will be made sticky thread.. and people repairing their cheap 60 $ radio themselves.. reversing the polarity and burning the radio is the most unacceptable mistake though ,( i burnt 2 radios like that)..huh.. but still cheap fixes like this will help members a lot.

Kalyan da, i checked the voltage of the other IC i.e. 6206A,
Input Voltage is 5V (from 7805)
Output is 3.29V.
i campared it from chart, its correct. The IC seems functonal no doubt..  {:)}

I didnt checked the sticks and knobs by multimeter, as they are in action as per the Display mode(i.e. Menu-Settings-display)..
as i move any stick, screen shows the movement on display..

and the servos connected to Rx are free, i.e, i can rotate their arms without any hindrance and they remain wherever i leave them.

sorry i forgot to add that buzzer has the speaker damaged. i tested with alarm clock speaker, it is getting input. but thats secondary concern.


now what can be the next step? If crystal is the probable reason, how can they be checked?

Just check the trainer switch and the entire lint that goes from uC data to RF card.
Possibly PPM/PCM data not enter to RF block.
And check any servo terminal voltage (center and the dark one) at receiver end for receiver failure. (Mostly should be with no problem but for extra precaution as servos are free).

And if you have components, you can check the data Line pulse by series capacitor, antiparallel Diode+LED(red) and resistance 10 Ohm-220 Ohm). And a transistor may require for low voltage checking if bus voltage peak lower than 2 volt.

You can check with schematics. Turnigy 9x is same too.

Thanks

Kalyan sir,i do not get the data line pulse method of testing as you stated.
ill make other checking,and will revret soon..

kalyan da.i checked the trainer switch,its working.. i referred the diagramme, but now its getting beyond my understanding and resources,since i belong to totally different educational background.. any simpler way  ???
i am confused

hurray!!! {:)} {:)} {:)}

my radio is working now :) :)

what did u  do....! please share  ur experience... and what all u  did to  get it  right...will help some one with same prob...

ya vishvesh, it was a bit risky procedure..

story begins here:

i went to indiahobbyhut to show it to ravi there, but they are not so familier with flysky(they only use spectrum,futaba,etc), so he doubted the reciever.
He said my radio is all good.

I Recently i bought a new Rx from a LHS, and today i tested it with that Rx.
still not worked. :banghead:

Now it was time to doubt Module ;D..I opened it up, and found a big 78M05 IC. I doubted it, and measured voltage. I cant believe my eves to see readings of my multimeter. The IC was burnt,though it looked inact.
I didnt had patience, i opened one of my old(working) colour television >:D,and borrowed the same IC 8-)  :giggle:.
Just soldered it up, and its working  {:)}

I fixed the radio, ill fix my TV tomorrow ;D


during these days i did lots of experiments with the main board, and even burnt a three legged species, named "j6".I know kalyan da will help me to fix it.But Tx doesnt lack any performance so far.. soon be testing the range as well..

ill add surgery pictures by tomo..

edited: pics added

nice work.. this has to be a sticky thread now..:) 2 successful radio repairs. ;)

WAH BHAI WAH.

              ╔════════════════════════╗
              ║        CONGRATULATION.            ║
              ╚════════════════════════╝

J6 is written on component. Is it a two terminal device and a jumper ? Does it have conductivity between terminals. All you have to check taking out from board. But leave it at it is. Some jumpers, resisters with zero value may shows burning mark but still it works means just leave as it was till further problem occures. This may be due to it have to carry excessive current, but still survive with burnt skin. As you normalize others, it may not have to work in overload region. Just check how much heat it generates at present for safety.

Now what you find in 7805 ? Input output short ? or open ? What is the measured output voltage of 7805 ? It's reverse diode blast (situated inside for protection to blow out external fuse) and should be zero output voltage. And moreover overvoltage may damage connected sensitive circuit, but found working. So it might be opened.

I can try to get the above part if needed.

alkhovercraft, if you can manage the j6, please do it for my peace of mind..

kalyan sir, the output voltage is 5.1 V. I am not familier with the other terms so cant get.. but with the faulty one( 78M05) i found it to be 2.0,so changed it.. Now its showing 5.1V and module is working..

kalyan sir,j6 is a three legged species like a surface mounted transistor,thats all i know. i googled "j6 transistor" and found "j6" to be S9014 NPN transistor. If yes, i have 2 of them on a toy car reciever.. Shall i cange it? but they are not surface mounted,as the original looks on main board.

edited:
forgot to mention the output 5.1 is with respect to ground.
The 7808 in Module generated slight heat unlike that in the main board.

Abhay

it may generate heat. But not like burning one. so, no need to fear it.
S9014 is a General perpose transistor and you can replace it with any similar transistor. 9014 costs Rs.2-3/- It's TO-92 package. If you connect right pin to right place, it will perfectly work. you have to know which is emittor, base, collector by checking with multimeter.
http://www.sm0vpo.com:800/_pdf/SS/SS9014.pdf

thanks kalyan da.. recenty recieved my simulator cable from hobbyking.. its working with my futaba Tx, but not with Flysky one.
I think the above transistor is the culprit.
Will check soon and update the results.I have downloaded the datasheet.

One more thing.So far i have used my Flysky radio many times.its working great.

Thanks for sharing :) I have marked the polarity on my radio :D

With the workload slowly reducing and getting back to normal again, decided to do some DIY with the turnigy 9x. Soldered programming leads, flashed er9x, installed backlight, installed frsky. But managed to do the reverse polarity magic trick while installing a new lipo. Carelessness to blame :banghead: Turned on the radio, smelled something burning and switched it off. The radio was not on for more than 2 seconds.

After slapping myself a few times I opened up the radio and was surprised to see the main VR and capacitor intact. Checked the voltage on 78L05 and was getting noting on input. So I started looking for burned track and found it below the LCD ribbon cable. Replaced the burned track with a wire, started up the tx and I got voltage on 78L05 input, it was 12.3v, lcd backlight also started up but still the radio won’t start. Checked the voltage on output of 78L05 and it was 10.7v and it was getting hot. I don’t know how hot is supposed to get being a VR but you cannot touch it for more than 3 seconds.

Ok now thinking that the 78L05 is toasted I replaced it with a new VR which I know is working fine, a 78M05.This one is not getting hot but the voltage readings are still the same. Input ~12.3v and output ~10.7v. And yes ground on the VR is 0v.

Totally stumped guys, any pointers would be helpful. Please find attached pictures.     

I have deeply thought about the protection circuit using series diode. but it will reduce supply voltage and low voltage will show up before it occur. (0.45v drop for 1N4001). So, it may be with fuse and a reverse power diode that will blow up the fuse. However, biased MOS used as diode can solve this, but I have not tried it.
Of course, when you feed supply voltage >11 volt, I get some mal-operation in uC menu. Have you checked it ? If you use 8 duracell new battery, you may feel this. This may be due to overheating (Lack of heat sink) of power supply IC. Waiting for your reply.

Kalyan, I've used the radio for two days after doing all the mods on brand new duracell without any problem. I was also working fine with a 3 cell lipo untill I burned it with reverse polarity. If you see the last picture, I have now replaced the 78L05 with 78M05, which has a quite a big heat sink. And its not even getting hot now.

Perfect heatsink. But it is not a low drop 5 volt regulator (low drop required for 5V?) it have buuild in backdiode. So just use an 500mA Fuse in battery line and it will give you protection.

Its a 5v positive regulator and has been working well in another circuit. Fuse is a good protection for the future, but what do I do to bring my radio back to life. Please note that my radio is not fixed yet.

Either the burnt track also connected another node(s) or it shorted with another node. So, try disconnecting the track from both end at first with hot iron to remove short option. If still not working, check the track carefully. The circuit diagram (Posted earlier) may give you some clue. Hope it will recover soon.

You might want to try and check the voltage that the atemga (the main chip) is receiving between VCC and GND. pinout here:
http://www.futurlec.com/Atmel/ATMEGA64.shtml

Pins 21/52 (VCC) and 22/53 (GND)

The display has it's own set of positive and negative terminals for the LED backlight(which may be intact, which is why the backlight lights up). If you still see about 5v coming in on these pins, probably the chip is fried. Also connect it to the programmer, does avrdude/eepe/extremeburner read the chip?

Kalyan, i have checked for shorts on the connectors where i soldered the wire.

Girish, i connected the programmer and got nothing. Infact now my computer is not recognizing the programmer. I have used it  hundreds of times before. I believe the programmer is also dead now.

Will try to check voltage on vcc of atmega and confirm.

When your programmer was still working, and you connected it to the 9x, did the 9x use to light up or you had to switch it on from the front for programming. Reason why I ask is to know whether your usbasp was providing the +5v supply for the Atmega to be programmed. In case yes, then you were connected to the USB +ve supply and you added a battery with inverted polarity, complete shortcircuit. If the answer is no, i doubt that the programmer is out. I'm sure you must've tried plugging it into another USB port...Any lights on the programmer to show any indictation...?

I always programmed without the battery connected. And this time also connected the programmer without the battery connected. Without the battery also, the radio used to light up and boot up when connected to the programmer.

I tried the programmer in different port and different computers, but absolutely no sigh of life.

I'll confirm the voltage on vcc tonight. Does this sound like a short circuit? what could be the reason of the regulator giving out more than rated voltage?

If you want , you can try with my programmer..i flashed my kk2 with it last week...so it is working 100%

Which means you were taking the power from the USB port, all ok.


Which is absolutely fine, since the Atmega is getting its power from the USB port. However, if at this point you connected the inverted battery *alongwith the programmer connected* and switched on, I can see a chance of a shortcircuit, that also affected the programmer, but if the programmer was isolated from the circuit, it shouldn't have affected the programmer.

If the voltage reg is speaking out more voltage than required 5v, it is poofed up.


I didn't read the out voltage earlier...10.7 v  :o, it doesn't sound regulated anymore...and the uc is getting a royal screwing all that time. This is what the datasheet says"

• Operating Voltages
– 2.7V - 5.5V for Atmel ATmega64L
– 4.5V - 5.5V for Atmel ATmega64

My last bit of hope is to check voltage on the Atmega, I'm hoping that some short circuit before the chip might have protected it and thats what is causing the programmer to malfunction :-\

I received a few 78L05 in mail today, should I try replacing the regulator once again ??? BTW the last regulator was working fine before it was installed on the radio.

Yes, why not. The existing VR seems to have gone rogue anyways. I'd do this if I was in your shoes:

1. Desolder the assumed rogue VR, mark the Vout and GND pads.
2. solder two wires on the Vout and GND pads and connect them to 1.2 * 4 = 4.8 v rechargeable batteries (or a 5v mobile phone charger - without forgetting polarity) and check the ATMega if it's still sane.
3. Wire up the new one on a bread board, and check the supply one before actually trying to solder it on the motherboard.

Got it, thanks you Girish. Will try this tonight and report back.

I am a bit dissapointed that im unable to help you out.The thread helped me a lot.
I have a working radio.
All i can do is to check the things like voltage, resistance, etc. between points via multimeter and revert back if you insist.

Just let me know.

Thank you Abhay.

My new findings almost certainly confirm that the atmega is toasted. Removed the vr and connected 4.9 volts where the output terminal were soldered. Identified GND and VCC on the chip but found out the VCC pins are kept unused but AVCC is used. Measured voltage on GND and AVCC and it was 4.23, this means the voltage at the output of the VR was being fed to the chip. This means the chip has seen 10.7 volts on these pins. O the horror it must have been through 8-)

You are too girlish to feel the pain of a lonely chip :giggle:

 ;D so this one is going in the drawer for now.. may be i'll get a SKY9x (http://www.ersky9x.net/) board for it when it comes back in stock. Will get my new 9x this weekend, thanks to Saurabh for a nice deal :thumbsup:  Hopefully the new one will stay with me a little longer  :)

Time to hunt for a second hand 9x o salvage the mega or get hold of the ersky board.

Hi guys,after a long gap I thought to do some RC activity..I tried to modify my Turnigy 9x for a Life bttery and finally...
yes its burnt  :banghead: :banghead:

do not worry... it can be repaired.... hopefully you connected wrong polarity !!!

google it on net you will find solutions.

Krish there are some fuse wires inside the tx.. just open the back cover and check which one is burnt.. and replace that...
Don't worry.. ;D

Sent from my Canvas using tapatalk 2

Hi frnds,finally my tx got life by Girish  ;D..Thanks a lot for ur help Girish  :hatsoff:..

Always a pleasure sire.

Sanjay sir is going to kill me now, His Rx is like 5% away from completion for a long time....:D

Bang....you're dead :D

I joined this elite club of TX burner few days ago.

Here is exact status of my TX:

When TX is switched on, it boots up properly but does not bind to RX.

The light on FrSKY module does not glow.

I checked the voltage at the module input and it is around 4V.

As per specs of FrSky DIY module it needs input of 6-13 V.

Can you please guide me which VR (or any other component) is faulty?

Tried to search it by multi meter but was not able to find faulty VR as both the VRs near to capacitor gives about 4V.

Capacitor is showing 5v though.

Let me know if you need any other input.

Please help.

Try some basic chexks first. See if your frsky module is alive...hook it up.to a cellphone charger in corect polarity and confirm if the led lights up. Mosy likely its one of the vrs. What did u do ? Ulta battery?

@atul : may i know your binding procedure?? because i had frsky module and in the beginning i found really difficult to bind it :banghead:, later i followed some manual binding procedure then it got binded  :hatsoff: :thumbsup:

Thank you Girish

yes cell ph charger is good idea ..... i will try that.

I too think its one of the VRs .... but not sure... which one....

Nithinraj, it was already bind with rx but after polarity issue module light is very dim on 3s & completely off with 2S

If any one have good idea to locate faulty VR then please let me know.....

Thank you,
Atul

First use "use and throw type" AA battery having internal impedence and check the current and voltage.
The results tell a lot. Then power up block by block. and check. Please also check the Rx with a separate Rx first to eliminate Rx fault possibility.

Thank you Kalyan.

I will post results of these test ASAP.

This RX used to work fine with same TX and module light does not glow so I suspect its issue on Tx side.

But I got your point that before jumping to conclusion we should check all possibilities and be 100% sure.

Thank you.

ok, i tried to power the FrSky module with 4 AA cell and nothing happen.

After opening the module cover i noticed that one IC is burned other one is getting very hot.

Here is pic of module that shows burned IC.

I cant read the complete # on IC  as its partly burned.

Here is what i can read.

164331
****BM
****CY

This is the first IC on board that is connected to power input wires.

My guess is this also VR.

Please let me know if i can replace this burned IC/VR? where can i get this? what is complete # of IC?


Also any details you may have...

Thank you,
Atul

Ok, Quick google search tells me ... It's a Texas Instruments TPS 54331 3.3 volt 3 Amp regulator

Next question is : Should i just replace VR of module and try again or should replace all of following?

1x VR (Part # LM78L05ACZNS-ND)
1x VR (Part # 296-11118-1-ND)
1x VR (Part # NJM78M05FA-ND)
1x VR (part # TPS54331EVM-232 3-A)
1x Cap (Part # 478-1682-1-ND)

can any one tell me what should be reading of out put V for all of above?

http://www.aliexpress.com/wholesale?SearchText=54331&catId=0&initiative_id=SB_20131122200922

Getting one piece might be difficult and expensive from Ali. I can find around locally in Chandni Chowk and let you in a day or two.

Spoke to some guys around. They dont have the TI 54331. They only have the LT117 which I don't think is a drop in replacement nor has adequate throughput (650ma vs 3A) so the best bet at the moment is Ali

:(

could you wait for today I'll ask a shop near my house for this IC.

Found some more information

http://diydrones.com/profiles/blogs/3-50-repair-frsky-diy-dht-module-after-reverse-polarity-mistake

http://il.farnell.com/texas-instruments/tps54331d/buck-3-5-28v-3a-570khz-8soic/dp/1645383

Farnell and digikey have a high shipping cost. If youre not plannig visiting the store you might be better off getting the diy kit from hk and replace the entire module.

Oh ok.. I discussed issue with few SME and they said ideally i should get the VR locally... Did you got chance to check in local market?

Yups, probably you missed my update earlier. They only have LT117 which is not a drop in replacement :(

Thank you Girish.

do you think its safe to put new module on this tx?

Should i perform any check before putting new module on this TX?

At the onset I doubt there will be a problem, besides that the FrSky might not even power up if a vr inside the Tx has also gone kaput!

So things surely will help if everything is found in order before hooking up the new kit. Do check the voltage that's coming out of the tx and if you can, do check the PPM signal as well. You can check the PPM signal by using a normal audio cable, plug it in the microphone port of your pc, and the trainer port on the other side. Download something like winscope, you should be able to see the PPM signal on your computer. If the PPM, +ve and gnd are in order, all should be well.

Sorry, not the trainer port but the ppm pin and gnd, outer shield of audio cable will go to gnd

Wow that is great idea. Thank you.

So now i have 2 things to do...

1) check output of all VRs

2) Check the PPM signal

If all ok then install new module

Thank you,
Atul

Applications of TPS 54331 are :

Consumer Applications such as Set-Top Boxes, CPE Equipment, LCD Displays, Peripherals, and Battery Chargers
Industrial and Car Audio Power Supplies
5V, 12V and 24V Distributed Power Systems

My side project is searching TPS 54331

Spot on. All the best  :thumbsup:

One more thing you need to check for...Beer in the fridge or scotch in the bottle...might come in handy when you can't find which solder join ain't working...;)


If you find some 54331, lemme know, I may barter it with some Scotch ;)

Deal Done sir  :hatsoff:

Some of my colleagues visit US frequently. I will try to source from there.

I appreciate your support and guidance.

Thank you,
Atul

Hi All,

I recently burnt my Turnigy 9x transmitter by connecting the battrey with reverse polarity, After switching on within seconds I got smoke and burnt smell from the transmitter. Later I noticed my device has been burnt due to reverse polarity.

I referred many forum and many of them had hit with this problem and the solution was to replaced Voltage regulator(VR), SMD capacitor and 2 more componenet. I replaced all the below listed componenet referring the link

http://openrcforums.com/wiki/index.php/Reverse_Polarity_Brick_-_Fix

1. 78L05 in SOT-89 package in the mainboard
2. replaced with 22uf 25v capacitor in the mainboard
3. 78L05 in TO-92 package in the switch PCB

I have not replaced "78M05 in TO-220 package in the RF module".

During the tranmitter burnt, I was hit with another problem, were my "Rhino 2620mAh 3S LIPO" got bad. One of the cell had gone bad, Now my output from the battery is only 7.24v. When I test my transmitter after replacing the component(with the 2 Cell LIPO), The 78L05 VR input in the mainboard  gets 7.24v but the output is only 0.32v instead of expected to 5.0v. This is unique where none has reports. I have tried replacing 2 nos 78L05 VR in the main board but still the same.

I have attached the photo with input/output marked. Please someone guide me to resolve the problem.

surprisingly, polarity protection is easiest thing to do. I wonder why they do have it: http://www.instructables.com/id/Reverse-polarity-protection-for-your-circuit-with/

There are circuits with 0v drop, but this is simple.

Girish another one for you...... seeing so many cases of wrong polarity I am planning to make and sell a connector for all.....

Please someone guide to resolve....

http://www.rcindia.org/radios-and-receivers/burn-turnigy-9x-transmitter/msg161861/#msg161861

Send him PM --- girishsarwal  ..... he will help you out.

I would recommend you to plug sim cable and see of your TX is working fine.
If yes then replace the VRs in order and after every replacement check the voltage.

girishsarwal is SME on this and he can definitely give you some good advise 

Sorry Purush, I was really caught up with so many things over the past two days...

Glad to hear, Purush has been able to fix his radio by replacing the VR....Sorry Purush, I could not help you in time...

GS

PS: While I've had quite some success in modding and fixing many of these, I am certainly not an SME on 9xs or electronics for that matter...Another hobbyist with a knack to open up things ...:D Happy flying!

Saurabh sir, banao banao, mere liye bhi ek (actually chaar paanch)...:D

Finally I was able to fix my transmitter, It looks like the replaced 78L05 VR on the mainboard was also a faulty VR, I replaced third VR and fix all the problem and got beep sound and display....

Some time back I mail you regarding the reverse polarity with my turnigy TX and I was able to fix after replacing the below parts including the RF module.

1. 78L05 in SOT-89 package in the mainboard
2. replaced with 22uf 25v capacitor in the mainboard
3. 78L05 in TO-92 package in the switch PCB
4.  "78M05 in TO-220 package in the RF module".

Now the issue is, when I connect my lipo will full charged, the display show in 10.7v instead of 12.1v. I confirmed with multimeter the lipo has 12.1v. when the display comes to 7.6v after some usage, the TX start to beeps...., at the time if I check with multimeter is only 10v. what is the reason behind.