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.

Now it was time to doubt Module ..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 ,and borrowed the same IC  .
Just soldered it up, and its working  

I fixed the radio, ill fix my TV tomorrow


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.

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              ║        CONGRATULATION.            ║
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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.

Quote from: gbisht on February 20, 2012, 02:03:39 AM
I think I have burnt this component (electrolytic capacitor)
http://search.digikey.com/us/en/products/TAJB226K016RNJ/478-1682-1-ND/564714

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

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 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%

QuoteI always programmed without the battery connected. And this time also connected the programmer without the battery connected

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

QuoteWithout the battery also, the radio used to light up and boot up when connected to the programmer.

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.

QuoteOk 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.

I didn't read the out voltage earlier...10.7 v  , 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.