I have been repairing my B126 CD Player recently which has a problem on the Servo board, and I decided to take another stab at the repair.
I turned the unit on to make some measurements on the Servo board, I noticed the PS voltages were all wrong from the day before, so I decided to check the power supply itself and noticed the +5V & +10V & -5 & -10V supplies are now reading +0.2V (+5v) & +0.7V (+10V) ; -1.5V (-5V) & -1.5V (-10V).
Note this cd player has a standby power function as well which may complicate the troubleshooting
Refer to attached marked-up PS schematic pdf file for details.
Any help would be appreciated.
Thanks in advance,
I turned the unit on to make some measurements on the Servo board, I noticed the PS voltages were all wrong from the day before, so I decided to check the power supply itself and noticed the +5V & +10V & -5 & -10V supplies are now reading +0.2V (+5v) & +0.7V (+10V) ; -1.5V (-5V) & -1.5V (-10V).
Note this cd player has a standby power function as well which may complicate the troubleshooting
Refer to attached marked-up PS schematic pdf file for details.
Any help would be appreciated.
Thanks in advance,
Attachments
hello.
can you test q2 /bc547.........(and perhaps q3 /bc557)...........perhaps they are damaged.
greetings
can you test q2 /bc547.........(and perhaps q3 /bc557)...........perhaps they are damaged.
greetings
Transistors Changeout
Since all the voltages on the base of the NPN & PNP transistors seem to be reversed, I am going to change out Q1 thru Q5 to be safe. I have checked the resistors as they seem to be OK but I will check again to be safe.
Thanks,
Since all the voltages on the base of the NPN & PNP transistors seem to be reversed, I am going to change out Q1 thru Q5 to be safe. I have checked the resistors as they seem to be OK but I will check again to be safe.
Thanks,
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