Hi,

Fried my fs th9x transmitter yesterday by connecting lipo in wrong polarity.....
POP sound and lots of smoke....

I m new to this hobby....Does this happened to anyone before?
Plz suggest how to repair...

thanks...

Can you upload clear close up pics of Circuit board ?
Kalyan Da , Saikat da , Ujjwaana , Sushil anand , Sadnam Alam can help you 

There is a 3.3v regulator which is probably that has been fried, if you are lucky. There are more failure points, but cannot say until seen in real. If you were in my city then would have helped, get help in your city who has sound knowledge in chip level servicing and who deal with radio/walkytalky sets..

@kjain,
Send a pm to umayash1.
I don't know if he knows electronics, but he is an experienced aeromodeller, and is in Bhopal.

http://www.rcindia.org/radios-and-receivers/burn-turnigy-9x-transmitter/25/
http://www.rcgroups.com/forums/showthread.php?t=1415356

Something for you to read and understand the procedure. First identify whats working and whats not, then get the components.Getting those components would be a task.

If you are a DIY'er you can do it yourself, or get the components and go to nearest mobile repair shop and tell them what you want to do(so you will need to know what has to be done) or get help from someone who knows how to do it.

here is some close up pics...

Good to see people in this hobby in bhopal (my home town)
1. Remove that bowled component it must be a filtering capacitor (it has big foot print and connected to ground at one end)
2. Do you have multimeter ? plug in supply and check voltage between 1 and 2 pin of component 78L05 it must be supply voltage (i.e. battery)
3. Then check voltage on between 3 and 2 it should be 5v +- .05 volt. if it is working at least power supply isworking.
4. Test your transmitter if its working.
5. If its not working may be your micro controller is dead.

filtering capacitor can be replaced if we know if it exactly a capacitor usually digital circuit has that tolerance without it.

Note: These are just suggestions, it can be possibility at applying voltage on step 2 something else blow, so be cautions if even try these step.
 

ya that is capacitor,

got this image from google. http://img11.imageshack.us/img11/4479/dscn4345c.jpg

dont perform step 2 as you can change that capacitor first.

and that capacitor is tantalum capacitor with code 106 must be 10uf have to check as i am not in electronics for some time.  if that is 10uf than it can be replaced even with simple electrolytic capacitor.

 Nice troubleshooting ..

actually i also burned my 9x about a year ago due to wrong battery polarity.
i fixed mine by using a standard size 7805 and soldered the wires as shown. the 7805 could be placed far as convinient. and moreover u could skip the capacitor as well it will not harm your tx. well i haven;t used it n its working since a long long time
and this way the repair cost is also down to a mere few bucks.

Hello nchandra

Thanks for the troubleshooting...
I've been searching myself for and some of blogs say it is code 226 tant cap....which is 22uf
which cap i use 106(10uf) or 226(22uf)?


And and dont have SMD workstation...can i remove the burnt part with my soldeting station?
Will it damage the board?

hi Vishal

I m gonna try replacing the cap first....Not sure that 78LO5 is damaged or not.

the first thing which normally goes is the 7805. and if u want the capacitor just use a standard electrolytic one.

It is a 10uF 25V tantulum capacitor, check this link, also a good electrolytic capacitor can be substituted, but at the expense of efficiency. Maybe even the other red circled components in the pic below to be changed too for peace of mind.

Refer Kalyan Prodhan's shared schematic of the tx here. Again, if you are not confident with smd level soldering skills, get professional help and get it fixed. Good luck!

edit: spelling

can try without capacitor, you dont need smd workstation for this,  Most of the time components get short circuited once they blown, you can cut burned capacitor from middle with small wire cutter, caution not pull component vertically by force as it will peal off copper tracks just cut it from between.

if 7805 is dead, then vishal's suggestion is good.

 

Finally after long time got the parts...i.e. VR and capacitor and replaced them....between found that i'have also fried the Amtel Microprocessor chip....

Have anyone have any idea how to replace that.....

smd rework station is recommended for the job with skills, provided the pcb traces is intact. You will need liquid flux [and some desoldering wick i you are planning to remove the chip with regular low watt solder gun], and solder paste to resolder in place with a flow soldering method. google it and you will find a whole lot of videos to learn and do, if you dont know how to.. good luck

Hi tantragna ...

I have already removed the processor.....but where to buy one?
And after soldering it again do i hve to flash it with firmware?

yes, the flashing of the firmware is needed as the new replacement chip will be blank/erased state.. try in local e-shop/ebay/online-electronics-stores/.. sourcing the chip is a challenge, but you will need to get it.

@Kjain: This weekend I'll visit a local electronic component dealer to get some items. I could look for ATmega64 microcontroller if you want. Recently I bought ATmega32 from the same shop so I think this chip might be available.

Hi phanivyas

Thanks for the help but i already ordered it from ebay.com this morning.

Can we use normal capacitor of 10uf

Yes. Electrolytic cap will work.

Tq u bro (kiran)