0

I think I blew something up...
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

I think I blew something up...

by AntoineSG on Mon Aug 22, 2016 4:58 am

Hi there,

well I wanted to build my own TV B gone but I messed up.
I soldiered everything properly up until the green led test which worked.
Then I did the rest but had no proper clipper to cut the legs of the components off.
And I mistakenly soldiered the EU zone resistance in R2 instead of R3 (call me dumb)

I inserted the batteries in the end and pressed the button, the green light was flashing but something went POP on the board, there was a little smoke and it smelt like burning.

It doesn't look like it's working now, although the green light test still works.
I guess I created a short circuit with some components legs touching each other (stupid me). Or maybe some bad soldier bridge, I haven't soldiered anything since high school and that's 20 years ago... Must say I'm kinda rusty on this, but multimeter testing doesn't seem to make it beep on my worst soldiering points so I guess there is no issue there.

My question is. How can I find out what blew up? Nothing looks dark the 4 IR Led don't seem to do anything.
When I test the transistors, condensers, resistances and LEDs with a multimeter they still seem to show some resistance value. When I test the LEDs with the multimeter though only the green one lights up. No Idea how I can test the microcontroller.
I'll send pictures when I get home. I'd be happy to find a way to fix it instead of ordering a whole new kit...

Thanks a lot for your help

AntoineSG
 
Posts: 5
Joined: Wed Aug 17, 2016 11:09 am

Re: I think I blew something up...

by adafruit_support_bill on Mon Aug 22, 2016 6:01 am

If the green led is still flashing, the processor is probably OK. If the IR leds are not working, it is possible than one or more of the drive transistors is damaged.

adafruit_support_bill
 
Posts: 71426
Joined: Sat Feb 07, 2009 10:11 am

Re: I think I blew something up...

by AntoineSG on Tue Aug 23, 2016 4:13 am

Hi thanks for your reply.
I pushed my tests further. Turns out 3 of the 4 leds are working fine. only the 3rd led does nothing.
When I test it with my multimeter it gives the same resistance as the other leds. When I test the associated Transistor it works as well.
Any idea on how I could find out the faulty component? Otherwise I'll just change both (the led & transistor)

Also, are the differents frequencies sent on all leds at the same time (in which case it should work with just 3 leds wouldn't it?) or are the different frequencies spread out on different leds (in which case until I fix this it won't work on certain TVs).
Thanks

AntoineSG
 
Posts: 5
Joined: Wed Aug 17, 2016 11:09 am

Re: I think I blew something up...

by adafruit_support_bill on Tue Aug 23, 2016 6:12 am

All 4 IR LEDs are being driven with the same signal from the processor. If one of the 4 is not working, the problem is almost certainly with the transistor that is driving it.

adafruit_support_bill
 
Posts: 71426
Joined: Sat Feb 07, 2009 10:11 am

Re: I think I blew something up...

by AntoineSG on Tue Aug 23, 2016 6:46 am

OK cool, thanks a lot for your help. I'll fix it tomorrow then!
Thanks a lot for your help, great products and great community!

AntoineSG
 
Posts: 5
Joined: Wed Aug 17, 2016 11:09 am

Please be positive and constructive with your questions and comments.