Hi,
New problem...
I was using the power supply, fixing a Ham transceiver, turning ON/OFF channer 1 from time to time, and suddenly I got an error messages rolling about overvoltage / overcurrent alarm... but the channel was OFF
![Shocked :o](https://www.eevblog.com/forum/Smileys/default/shocked.gif)
The output was sets to 9V - 2A, draining ~200mA.
I tried to change output settings, no way, same problem.
At a moment, I checked with my DSO... errr >43V nice sin wave
![WTF? :wtf:](https://www.eevblog.com/forum/Smileys/default/wtf2.gif)
(sorry, no screenshot)
Well, I've opened today, once again, checking test points.
The 2.5V (next to 2.5 ref) seems wrong. Out of the 1117 regulator, 2.5V is there, but on C31 (22uF) 1.63V. I suspect the erased chip next to this capacitor have a problem...
![Embarrassed :-[](https://www.eevblog.com/forum/Smileys/default/embarrassed.gif)
I checked C31, it was dead (few pF), replaced, still 1.63V.
Also, I checked peaks when you turn on the power supply, terrific... (on +2.5V, -2.5)
I guess I have to contact Rigol for a new board, I don't have too much hope about fixing this one.
Cheers.
---
Daniel.