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Newb: Replaced STM32, boot loop when switched OFF

Posted: Tue May 08, 2018 5:17 am
by risben
Hi All,

First post, hope it's not out of order.

I killed my STM32 in my taranis+ by d/cing the ribbons with the battery still connected. Found out why that was a bad thing after the fact.

Anyways, new chip soldered in, flashed firmware fine, all good, but:

1. When I turn it off, it goes into a boot loop of about 1/2 a second in length.
2. The left trim switch (aileron for mode 2) triggers "right" if you move it to the left
3. Switch B is hard set to up/back

I'm thinking I've shorted a lead or two on the STM 32, and was hoping someone with a bit of awareness of the board (or even a schematic) could point me to which pins are associated with the above connections. My eyes are getting sore from trying to find a short.

Any ideas?

Re: Newb: Replaced STM32, boot loop when switched OFF

Posted: Tue May 08, 2018 7:26 am
by CatRovacer
How you removed old death STM32?
Reflow with hot fan or just cut pins one-by-one/
May be hot air stream too strong and shifted some C or/and R's?

Possible shorted pins also need check. Use power magniefing glass and LED torch.

for removing solder snot/drop between pins i use "wave soldering tip"

Re: Newb: Replaced STM32, boot loop when switched OFF

Posted: Tue May 08, 2018 1:29 pm
by MikeB
Check pins 1,2 and 3, these relate to switch B and a trim.

Mike

Re: Newb: Replaced STM32, boot loop when switched OFF

Posted: Thu May 10, 2018 5:39 am
by risben
turns out I missed a few pins when soldering. Thanks for your help :)