RC India

hi friends..
i have a 6 channel skytech t6i 35 mhz radio..
during use, accidentally, i put transmitter battery in wrong polarity with radio.
as a result , computerized screen stops working while the radio is working means all the channels are working fine.
plz suggest me a solution so that computerized screen starts working again?

thanks

Wow!! I did the same last night with my Mini-box PicoUps 100 for my NAS box. I put the SLA battery connection reverse and blew the Batt Mosfet.

Just check if there was a protection Diode on the power line in the PCB. if so, check with a Multimeter if it is working (should move the meter needle only on opposite polarity) .if the diode is blew up , you just need replace the diode. Other wise finding the damage would be difficult on the main board..

my electronic teacher saw the radio , checked whole ckt. and said all components are looking o.k ,
there might be a problem in micro controller...
and i ,a mechanical student , i left with :headscratch: :headscratch:
plz suggest me , what should i do?
thanks

kalyan sir , sultan sir , ujjwaana sir and other experts ....
plz  :help: :help:

Aditya, Please post high resolution pics of the Tx board. Or upload the pics in any other picture host (even in pages.google.com of your email account) so that we can analise the circuit and guess the culprit. Mostly the series bleeder resistance of the voltage regulator (Zener only) gets open or small TO220 package LM7805 damaged.

There be surely voltage regulator circuit before display microcontroller/driver. and The safeguard scheme was always there. So dont worry. Ujjwaana sir have fixed his Tx and you will too.

JUst asking, check for PCB Track fuse if blown.

Ujjwaana

A reverse polarity protection diode works by not allowing any current to pass if the supply is reversed. Unlike a fuse, it does not get damaged in this process. And if there was one in the circuit there would have been no damage done to the circuitry.

thanks Kalyan sir..
i am posting a high resolution picture of tx circuit..

Sushil sir, you are absolutely right. I got mixed up with over voltage protection diode.

Well I can see a protection diode at the right bottom. I would recommend you to get the Tx to some qualified Electronics repair guy or DIY electronics enthusiast. Not necessarily to just any EE/ECE student, as I have seen some pathetic electronics engineer [:D]

"some" ? You are being kind!
Unlikely to be the diode anyway as part of the Tx is working. The display is not.  So the supply  IS getting through.

Aditya, The picture upload limit here is 192KB. So, high resolution though you upload, does not seen to us. So upload in PIccasa or imageshack.us or in tinypic so that it comes original.
Moreover, the crystal (blue marked, microcontroller and it's surroundings supply is required to check. The display connectors, IC, and surrounding PS is eed to check.

Please see attachec pic.

The display driver microcontroller IC number is to be checked for it's datasheet. Then just power supply and crystal is the thing to be checked. If OK then you may need to check the display +ve and -ve supplys so that the display may got damaged only (chances low, display damage mainly high sunlight for cheap display, mechanical damage and terminal miscontact). You may check yourself.

The microcontroller's program is intact that is why, it's operating if it's only single microcontroller.

If possible, can you post the picture of the reverse side of the PCB.

I highly doubt picture would be of any help. A 7Ah SLA battery left *NO* visible hint that the MOSFET blew up on a reverse polarity on my PicoUPS board, I wonder anything would be left for naked eyes by the meek low Amp rating Battery of the Tx.

It is highly likely that the delicate Chip/LCD module went kaput due to the brief reverse polarity, if there were no protection diode. Even if reached to the conclusion, Aditya has to get hold of a guy who can do SMD soldering for any replacement. Then why not ask that guy to do some diagnostics.

sir
i am posting pic on picasa..
here is the link..
https://picasaweb.google.com/104283080611943381455/Desktop?authkey=Gv1sRgCILwmb-miLjPzwE#5636946691017493554
thanks sir

sir
i checked the input voltage at microcontroller input terminals, it was o.k (matching with input voltage given in Datasheet).
thanks..

will try to put pics of opposite side of pcb as soon as possible.....
actually , i saw reverse side of pcb before also , but there was no signs of burning , spark etc...
also , there were hardly 1 or 2 component ...

 :help: :help:

Adita, Just try to read all the resistance values. If it is readable, It's OK.
I cannot find any problem. However, just re-solder the diaplay terminals from mcrocontroller PCB. Up & Down terminals of Microcontroller position.

Look, the white colored small two terminal components are capacitors and similar black colored components are resistors. The resistor values are written on it. If those burnt you cannot read it. Sometimes, they break into pieces but looks as it was earlier, So, this can be checked with magnifyng glass. Please check these items.

If nothing found outside on the PCB, chances are fault inside the controller and cannot be recovered.

link for the pic..
https://picasaweb.google.com/104283080611943381455/Desktop#5636946691017493554

ok sir , i will check all resistance and capacitors....
if there is any problem in microcontroller , can it be replaced? is it feasible ?
thanks

No, Microcontroller is not only a IC but a programmable IC. You can buy the same without program. Generally, this type programs are locked by the manufacturer so that it cannot be cloned by other company or can publish with little modifications. Now-a-days, some Txs are coming with open source code but not this one.

Sorry aditya.

This (Sky tech t6i ) transmitter have a audio jack type socket in back and written' trainer' there.
can it b use as simulator?
plz tell me the procedure of using it as simulator.

You should have an audio cable lying around with 3.5 male headers on both sides plug one into your RC controller and the other into you computers Audio in or Mic input. After that download SPP console and FMS running the SPP console will allow the computer to understand the audio signal the controller send over this line and always keep the SPP console minimised, this will allow the computer to detect the controller as a joystick.
 Note: I have a turnigy 9X I had to remove the 2.4 G module for this to work. you might also have to remove it. And I did not need to switch on the controller as it would switch on as i connected the 3.5 mm jack.

before doing this please do confirm your controller is compatible with this method or not.

from where can i download spp console ??

FMS also not installing in my computer.
the error message is " fms.exe has encountered a problem and needs to be close. we are sorry for inconvenience".

Aditya I dont exactly remember from where I got the links but it was from the forum and all the instructions were there. I am uploading the files to my server, you can click the following link to download it.
http://www.roboinventions.com/Remote controlled plane simulator.rar (http://www.roboinventions.com/Remote controlled plane simulator.rar)
Hope this will help you out.

the above link has been removed as OP has downloaded the file.

thanks Prateesh...
my transmitter is detected by pc as joystick.......
Fms also starts...
but
all the signals in calibration mode are fluctuating ........
so no control on sticks  and plane after calibration....
plane starts  and crashed....
and sticks are responding lazy.....
what to do??

Do you have gud quality Audio cable or is it an improvised cable. Audio cables dont have much circuitry but will save you a lot of hassle if you spend 30-40 Rs. on a gud quality cable. And also remember to remove the Module wen connecting with Sim.

i bought it from market...
not DIY .....
also removed the module......
but no improvement.....

after connecting  transmitter  with mic o/p...
what to do?
transmitter should be on or off?

reply anyone plz....

for my transmitter the power switch was in off position and when I connected the audio cable it switches on automatically.