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
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
(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...
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.