Bought it broken to compliment vintage Meridian pieces. It was exhibiting typical TDA1541 crackling sound symptoms and as a transport it only played first few tracks and refused to go forward. I thought it will be rather easy fix but I was wrong. I replaced TDA with a chip from donor board I vaguely remembered it was working. Voltages seemed correct but it didn't help. There was no output at all. Frustrated I pulled the chip and put it in my DAc .It was working fine . I checked old chip ( S1) and surely enough it was fried. I put it back , checked and re re checked and again nothing. I cut out Meridian output IV stages and installed resistors to check nothing at all. Damn it. Since no schematic is available decided to use machine as a transport only and pulled the chip again which pretty much damaged fragile plated throug PCB tracks. Still salvageable and I have 28dil socket on order. Back to transport. Thinking that recap will fix the tracking issue I took it apart and replace servo capacitors, Psu caps and all el caps around transport serving chips . Nope . The mech is rare as hen teeth CDM4/21 . It's not an issue with clamp since Meridian is using custom clamping arm where nothing wears out. It's just a plastic platter spinning against flat metal surface. Player plays 3 to 6 first tracks then servo makes some screechy sounds and the playback stops. I didn't get to mechanism own control board with potentiometer not seeing any capacitors there.
Anybody familiar with quirks of this machine. I replaced SA7220ap and it made no difference. Bummer
Anybody familiar with quirks of this machine. I replaced SA7220ap and it made no difference. Bummer
You did not “choose” the simplest from a PCB assembly and quality point of view.
The CDM 4/21 is a little different from the 19 but it is mainly mechanical differences.
Firstly, on yours, I would like (to see if it makes a difference) to run the spindle motor with a battery-powered screwdriver (motor disconnected) by injecting contact cleaner into the motor, and then see if that changes the problem or not.
The problem with this model is that nothing is easily accessible in the "mechanical/servo" box and you have to be patient.
When dismantling, take the opportunity to check the regulators and capacitors of the servo PCB.
The CDM 4/21 is a little different from the 19 but it is mainly mechanical differences.
Firstly, on yours, I would like (to see if it makes a difference) to run the spindle motor with a battery-powered screwdriver (motor disconnected) by injecting contact cleaner into the motor, and then see if that changes the problem or not.
The problem with this model is that nothing is easily accessible in the "mechanical/servo" box and you have to be patient.
When dismantling, take the opportunity to check the regulators and capacitors of the servo PCB.
You're right that I didn't research and took a gamble. I will do what you advice once I take a break from the machine. I fried my dac trying to revive it so I need to take a breath. I was testing 220V pre out of step up transformer and left the the power cable stuck into step up. I brought my dac to check the transport and without thinking twice I plug that power cable into 120V inlet. The fuse popped but the power module fried giving out 24V instead 12V . Not sure if dac module survived. At that point I was ready to pack everything into garbage bag and dump it into the dumpster ...😉
Thank you very much for insight and I will update once I take the clunker apart again.
Thank you very much for insight and I will update once I take the clunker apart again.