BM 4400 Mexico

13 replies
mexking
Offline
mexking
Bronze
Posted June 13, 2024 at 16:17 GMT
Edited June 13, 2024 at 16:17 GMT
#1664994
That didnt work, cleaned all properly and colocated the transistors again with new insulators and Thermal Paste in the left channel, and have the same failure. I have never had the same failure right and left, so I am a little lost where to start looking but as I never give up I will start checking from the preamps and onward

Location: Mexico city

Retired
Printing machine technician
Restored various 1960-70 items
Rock and Roll music
Collecting Vinyl
Restored Jukebox Wurlitzer 1050
DI
Offline
Dillen
BronzeModeratorFounder
Posted June 13, 2024 at 17:35 GMT
#1664995
Put a scope on an output.
Check for oscillation.

Martin
mexking
Offline
mexking
Bronze
Posted June 13, 2024 at 18:25 GMT
Edited June 13, 2024 at 19:45 GMT
#1664996
Thank you Martin, will do

Its 5-6 years ago that I used my oscilloscope and I didn't use it that much so I will have to get into learning again, not a problem but will take a little time

Found my old thread here

Location: Mexico city

Retired
Printing machine technician
Restored various 1960-70 items
Rock and Roll music
Collecting Vinyl
Restored Jukebox Wurlitzer 1050
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