ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi
I've bought a pair of BL4000 and a BS2300. I knew there were issues with it and I do know about the famous sticky black foam in the Beolabs.
But no risk - no fun.
I took both speakers apart. Cleaned the amp, put new foam in. Success with one speaker ... But not with the other.
It stays in stand by. Does not power on neither via PL or RCA.
I have a multimeter but I am not very qualified in using it and I read a lot of posts in this forum but have not found a step-step guide.
A bit of help would be appreciated.
Would like to bring this beautiful speaker back to life...
Regards
Ravsted
Close up picture of area around P4
Assume P4 + ribbon cable is triggering the relay ? If so... can I bypass that just to check if the amp is working then ?
I measure 28V between pin 1 and pin 2 on P4.
According to service manual it should be 23,5 in standby.
Fuses F1, F2 and F5 on PCB1 (PowerSupply Board) are fine.
I have also checked TR91, TR92 and TR93 on the Amplifier Board. I get a reading on all 3.
What would be the next thing to measure and how do I measure ?
Manual:
http://www.ravstedlokalhistorie.dk/share/document.pdf
Maybe I am getting closer to a reason
Resistor TR91 and TR120 should be NPN type BC847B
I have correct reading on TR91
But TR120 gives me a reading both ways between Base and Emitter. Guess that is wrong.
Service manual says: Check that 2TR120, 121 and 122 are all pulled on. But what does that mean ? Pulled on ?
I had the same issue.
exchanged the 100 ohm resistor 101 and now it works again.
it’s close to the p4 panel
best regards
69er