CD Player Repair Advice

Mark B · Sunday at 1:16 AM

Hi there. This model is 30 ish years old. Sony CDP-CX355. I replaced the drive belts due to age and fired it back up and got a clicking noise out of the power relay. I replaced it cheaply. Same clicking. I don't wish to pay anyone. I thought I was so close! Let me know your ideas. The power won't come on.

TLS Guy · Sunday at 9:45 AM

Mark B said:
Hi there. This model is 30 ish years old. Sony CDP-CX355. I replaced the drive belts due to age and fired it back up and got a clicking noise out of the power relay. I replaced it cheaply. Same clicking. I don't wish to pay anyone. I thought I was so close! Let me know your ideas. The power won't come on. View attachment 77716 View attachment 77717

Recycle. Not fixable and new would be cheaper anyway.

Eppie · 2026-02-17T11:03:52-0600

Mark B said:
Hi there. This model is 30 ish years old. Sony CDP-CX355. I replaced the drive belts due to age and fired it back up and got a clicking noise out of the power relay. I replaced it cheaply. Same clicking. I don't wish to pay anyone. I thought I was so close! Let me know your ideas. The power won't come on.

You will want the service manual to tackle this. Link is below for electrotanya. The power supply board and circuit diagram are on page 44. The lower potion of the schematic is the relay circuit. I would start by checking Q930, the diodes and capacitors on that circuit board, but note that the circuit also connects to the main board so the repair may not be trivial if the problem is not isolated to the power board.

Elektrotanya for electronics experts

Electronics forum for electronics experts to repair defective appliance.

elektrotanya.com

TLS Guy · 2026-02-17T11:15:32-0600

Eppie said:
You will want the service manual to tackle this. Link is below for electrotanya. The power supply board and circuit diagram are on page 44. The lower potion of the schematic is the relay circuit. I would start by checking Q930, the diodes and capacitors on that circuit board, but note that the circuit also connects to the main board so the repair may not be trivial if the problem is not isolated to the power board.

Elektrotanya for electronics experts

Electronics forum for electronics experts to repair defective appliance.

elektrotanya.com

That was the site that gave me the worst hack I have ever had. Keep away is my advice.

Alex2507 · 2026-02-17T11:36:07-0600

I've been listening to mine all morning. Anymore it's like all the gear I use keeps showing up in threads about broke gear.

I feel like that kid on The Simpsons that says I'm in danger.

BoredSysAdmin · 2026-02-17T13:40:30-0600

If time is no issue, then instead of throwing it out, a self-repair might be possible. You'd need to figure out how and find at least the basic tools, like a soldering iron, a multimeter, and possibly a scope.
Check out this YT channel for inspiration and tips:

Mend It Mark

Vintage Electronic Repair & Restorations feature heavily in Mark's workshop, but Mark will work on whatever comes in! From gramophones to games consoles. Antique radios, classic computers, retro Hi-Fi, jukebox parts, and lots of things he's never seen before!

www.youtube.com

He has several videos on the repair of optical disk players.

Eppie · 2026-02-17T13:42:01-0600

TLS Guy said:
That was the site that gave me the worst hack I have ever had. Keep away is my advice.

I run uBlock Origin to block 3rd party content, which is usually where the hacks come from. I also prefer Firefox with its smaller user base as hackers tend to target Chrome and Edge. My anti-virus software has a web browser plugin that checks content as well. Never had an infection.

If you want complete security, then you need to run your browser in a sandbox or inside a Virtual Machine. If the Virtual Machine gets infected, you can just reinstall the OS or keep a cloned copy of the VM to over-write the infected copy. VMs can access a shared folder with the host OS so that files safely downloaded in the VM can be copied over to the host OS fairly easily.

BoredSysAdmin · 2026-02-17T13:45:54-0600

Google purposely broke uBlock Origin on Chrome. Now, if you insist on using Chrome, uBlock Original Lite is the only decent option. And if you want the full protection of uBlock Origin, then Firefox is the way to go.
Using the Internet without an ad blocker for the last 10 years is a recipe for disaster. Bad ads might show up even on 100% legit sites.

Eppie · 2026-02-17T13:57:51-0600

BoredSysAdmin said:
If time is no issue, then instead of throwing it out, a self-repair might be possible. You'd need to figure out how and find at least the basic tools, like a soldering iron, a multimeter, and possibly a scope.
Check out this YT channel for inspiration and tips:

Mend It Mark

Vintage Electronic Repair & Restorations feature heavily in Mark's workshop, but Mark will work on whatever comes in! From gramophones to games consoles. Antique radios, classic computers, retro Hi-Fi, jukebox parts, and lots of things he's never seen before!

www.youtube.com

He has several videos on the repair of optical disk players.

Mend it Mark is amazing. Not just his electronics repair skills, but his ability to manufacturer and machine new parts when required. A truly skilled craftsman.

While you can learn a few tricks from his channel, the best channel that I have seen for learning the basics is Learn Electronics Repair on Youtube. He goes over diagnostic methodology and explains how circuits work and what to look for. He has a series of 39 videos for beginners amongst other series.

Learn Electronics Repair

Hi, Welcome to my channel. My name is Richard and I aim to teach you all about Electronics Repair. I am a hobbyist repair technician with over four decades of experience in a variety of different repair fields. Previously I worked full time in Component Level Repair and I learned to repair a...

www.youtube.com

For vintage (tube) audio, Mr Carlson's Lab is one of the best resources.

FYI, Mark is in the UK, Richard is in the Canary Islands, and Carlson is in Canada. Carlson is another engineering wiz and designs his own test equipment, available through his Patreon channel.

BoredSysAdmin · 2026-02-17T14:01:22-0600

Eppie said:
Mend it Mark is amazing. Not just his electronics repair skills, but his ability to manufacturer and machine new parts when required. A truly skilled craftsman.

While you can learn a few tricks from his channel, the best channel that I have seen for learning the basics is Learn Electronics Repair on Youtube. He goes over diagnostic methodology and explains how circuits work and what to look for. He has a series of 39 videos for beginners amongst other series.

Learn Electronics Repair

Hi, Welcome to my channel. My name is Richard and I aim to teach you all about Electronics Repair. I am a hobbyist repair technician with over four decades of experience in a variety of different repair fields. Previously I worked full time in Component Level Repair and I learned to repair a...

www.youtube.com

For vintage (tube) audio, Mr Carlson's Lab is one of the best resources.

FYI, Mark is in the UK, Richard is in the Canary Islands, and Carlson is in Canada. Carlson is another engineering wiz and designs his own test equipment, available through his Patreon channel.

Is this the Carlson YT you mentioned? https://www.youtube.com/@MrCarlsonsLab/videos

Eppie · 2026-02-17T14:16:14-0600

Here is the power board with the relay (the mains plug cut off on the right)

BoredSysAdmin said:
Is this the Carlson YT you mentioned? https://www.youtube.com/@MrCarlsonsLab/videos

Yes, he is amazing with vintage radios and transmitter equipment. I learned some important points in working with tube gear on his channel. Some of his restoration videos are quite long though. I scanned through his channel and for a first time visitor there is a lot of fluff in there but some good educational pieces in there as well. I find his voice pleasing to listen to as well.

TLS Guy · 2026-02-17T14:19:17-0600

Eppie said:
I run uBlock Origin to block 3rd party content, which is usually where the hacks come from. I also prefer Firefox with its smaller user base as hackers tend to target Chrome and Edge. My anti-virus software has a web browser plugin that checks content as well. Never had an infection.

If you want complete security, then you need to run your browser in a sandbox or inside a Virtual Machine. If the Virtual Machine gets infected, you can just reinstall the OS or keep a cloned copy of the VM to over-write the infected copy. VMs can access a shared folder with the host OS so that files safely downloaded in the VM can be copied over to the host OS fairly easily.

U-block origin is done. But I was using it when I had the hack and it got past it. My son said that the hack was very advanced and dangerous and difficult to deal with. He is chief of Internet security for an International country. So my advice stands. Avoid those eastern European sites. One episode was enough for me.

Eppie · 2026-02-17T14:21:03-0600

@TLS Guy here is the power board with the relay:

Eppie · 2026-02-17T15:06:17-0600

@Mark B
If the problem is on the power board, it may be repairable. The small transformer T901 feeds four diodes that form a bridge rectifier and supply unregulated voltage VCC. On CN902 VCC is supplying voltage to IC931 on the main board and should be 7.9V. I think IC930 and IC931 are both voltage regulators. IC931 supplies 5.1V to the main system control IC (pin 11 VDD) and also the 5V back to the relay (+5V pin 1 on CN902). The AC IN and RELAY connections come from the main system control IC (pins 18 and 19), so the main control IC turns on the relay.

I would look at the components that form the relay control circuit on the power board. The relay switches on power to the main transformer. If the problem is not on the power board but the main board then the issue will be beyond the skills of most repair techs. There is the odd chance that IC930 or IC931 are defective, but if the relay is clicking on and off constantly and the power board is fine, then there likely is an issue with the main system control IC or governing circuits, in which case the unit is beyond repair.

TLS Guy · 2026-02-17T15:38:41-0600

Eppie said:
@TLS Guy here is the power board with the relay:
View attachment 77722

View attachment 77723

He can check those voltages easily, but should probably use a VOM amplified meter so as not to load the circuits. He will be lucky of the fault is on that board. I suspect the relay is clicking as something is trying to draw too much current from the power supply.

I agree the main board is unlikely to be serviceable.