Re: [Paparazzi-devel] YAPA v2.0 Hardware failures

[Chris]

Just to be covered from all aspects, are you sure that you have not 
connected the 5v supply from the BEC with the onboard 5v regulator rail?
Also what is your autopilot input voltage (it should be no more than 18v 
max)
I can understand the barometer going wrong and short circuit the onboard 
5v rail but not the
capacitor going bad because of it.
It is possible that the capacitor(s) are bad and might actually be the 
origin of the problems
you have or your 5v BEC is overshooting with high voltage spikes (bad 
BEC, or bad servo(s) ).
In any case try to power all sensors and rc receiver from onboard 
regulator's 5v rail
(it can also power the 9Xtend modem at 1w without any problem)
and power only the servos from the BEC.
Keep those two 5v +rail separate.
Chris

I remembered somewhat wrong. I went back and looked at them again. There are 
four that have gone bad:
1. This one happened just as I said. the 5v regulator went bad like you 
mentioned, and the 3.3v line is shorted to ground. but the 5v line is not 
shorted.
2. This one turned on, but gave bad pwm signals to the servos. as far as i 
remember, this one never actually quit completely.
3. This one a wire came loose and shorted so no question there.
4. on this one I plugged it in the other day and c38, the big capacitor on the 
bottom went up in smoke. battery voltage is shorted and 5v is shorted but the 
3.3v line is not. my guess is that this may be a short in the power supply as 
well.
5. This one I thought had done the same as #1 but on further investigation, i 
found it was the barometer not the autopilot itself. when I unplugged the baro, 
it worked fine.

I guess I really only have questions about 1 and 4.