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 everyone,
things have been pretty quiet until.....yes, until another little issue on the BM8000 !
in TP2 mode I lost the left channel - it comes on briefly after selecting TP2 and crackles out.
first I suspected IC1 being at fault, replaced it ...no change !
second I checked the connector box with the assigned 5Pin DIN input....all fine !
both trimmers R122/222 are new, only R122 shows audible change when turned, no reaction from R222 though as well as both assigned caps C112/212.
phono and TP1 work fine....does this exclude IC202 as a possible source of the issue ?
at the moment I can not see any other source guilty of causing that issue.....can one of you help ?
regards
ALF
To avoid misunderstanding C112/212 are new.
connection from PCB3 P14 to PCB9 P82 is fine as well !
Transferred a spare (not really spare) preamp board and the missing left channel in TP2 input mode is back 😁😁
my suspicion is going to the two switching ICs on board 3. Naturally those ICs are long gone.....the famous needle in the hay stack.
i can not see any other culprit on that board causing that kind of issue.
I checked the R222 trimmer and the designated cap...both fine and as said, IC1 has been replaced....what is left is that damn switching IC.
that is my diagnose.....but sadly no help/support ?!?
Have you seen this:
https://archivedforum2.beoworld.org/forums/t/33383.aspx
Martin
Thanks for the reminder Martin, much appreciated.
I made contact with John (sonavor) and yes indeed, the AD10/278 chips are the source of the issue my BM has.
the existing pair will be replaced by the new device !
alf