EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: amptub3ss on February 06, 2023, 08:15:47 pm
-
Hello,
I have a Sony CDP-C425 5-CD changer that sometimes works totally normally, but most of the time it will only show the tracks grid on the screen when it's powered on. The grid appears immediately when the power is turned on but then nothing more happens. This issue has gradually got worse and now it doesn't start up most of the time.
I measured the power supply output voltage and it seemed reasonable. Any ideas on what could be wrong?
(https://i.ibb.co/ZXFj9tk/sony1.jpg) (https://ibb.co/ZXFj9tk) (https://i.ibb.co/mNnRyMb/sony2.jpg) (https://ibb.co/mNnRyMb)
-
Solder connections, grounds, power supply or?
Jeff
-
The grid section may be wired to always be on with power, so it could be that the micro is just not running when the rest of the display is blank.
I just grabbed the service manual from Hi-Fi Engine, but other sources may have it too.
Check the voltage to IC401 and also make sure /RST is high. You can find this signal on pin 13 of CN301 (should be on front board). It comes from pin 5 of IC202 on the main board.
Some of these models develop cracked solder joints on the main PCB, especially around the RCA sockets and in the power supply section.
-
Thanks! Now I also found the repair manual. I noticed that if I disconnect the flex cable going to the BD BOARD with IC101 and IC102, it will start up perfectly. I can't see any obvious issues on this board, and there are motors attached to it so I guess I need to figure out how to remove it. The laser assembly seems to be attached to this board.
-
That may or may not be related to the issue. I still suggest checking /RST line and carefully resoldering any cracked joints.