Hi,
have just finished recapping a Marantz DD-82 DCC player's R/W and Digital boards.
Unfortunately found a blown transistor during the process, which is driven from the motherboard's 8v regulated power supply.
The transistor appears to be part of the bias system for the read amp chip analogue inputs, which are protected from over-current by a 560R resistor (apparently intact for both channels).
I'd like to test the motherboard power supply with the recapped boards out of the system - any thoughts on the safety of doing that, or why the transistor failed much appreciated...
Service manual (fried transistor is Q103 bottom left on p.45):
Marantz DD-82 - Manual - Digital Compact Cassette Recorder - HiFi Engine
have just finished recapping a Marantz DD-82 DCC player's R/W and Digital boards.
Unfortunately found a blown transistor during the process, which is driven from the motherboard's 8v regulated power supply.
The transistor appears to be part of the bias system for the read amp chip analogue inputs, which are protected from over-current by a 560R resistor (apparently intact for both channels).
I'd like to test the motherboard power supply with the recapped boards out of the system - any thoughts on the safety of doing that, or why the transistor failed much appreciated...
Service manual (fried transistor is Q103 bottom left on p.45):
Marantz DD-82 - Manual - Digital Compact Cassette Recorder - HiFi Engine
