HELP bogner alchemist switching problemi stucked in clean mode

[Slash_83]

Hi to all,


I have experience in electronics and tube amplifier repair, but all these semi-digital electronics confuse me a bit

This is the story of this alchemist :

I restored power supply back on it, the amplifier was working fine but with a lot of hum
I increased the filter capacitors in the while (220*2/100*2 500v)
Changed rectifier diode and capacitor 68000uf.
The amplifier was fine.

Playing today, after some day that as i said amp was ok, I heard a short and A small spark circuit somewhere and the amp got stuck on the clean channel
Only clean channel commands work, the relative switches treble crunch deep are ok
Digital effects work
I've checked voltage and they seem ok, so the power supply seems to be good. I'm afraid that some component in the relay circuit has blown
Tomorrow I will recheck the digital board from which the inputs for the channel change relays start (the one where the 7905/08 transistors are present, etc
I replaced q1/q2 with two transistors 2n3904

I'm trying everything, there are no burn marks, the only component that was blown is r4 apparently
I replaced it
Maybe I was tired and stressed and I got the wrong value
A little while ago I was reading is 1k
I'm afraid I used a superior value.
Any idea is wellcome

[Slash_83]

Meanwhile I found the error, r4 should have been replaced with a 1m resistor and instead I had entered an incorrect value
I still can't test because in the meantime I had disassembled all the power supply and I'm going to replace c6/c11/d7 because they had aged
The disassembled capacitors gave readings values other than the nominal ones
If there was no problem at the level of dsp (and I don't think so) somehow calmly I will be able to get out of it

[Slash_83]

Svp