Crackling sound from Philips CD100

[sweat100]

Hi all, I am new to this forum. I have just gotten a Philips CD100 off the bay. When it arrived and upon powering on, it started to have crackling sound occasionally when playing CDs. 2 days later, the crackling sound came as soon as I turn on the player. I have read this forum and it may seem to be capacitors at fault. However I am not sure if there are other faults. These are my observations on the player which I hope someone can help me.

Symptoms
1. Crackling sound occurs but I do not hear hum. It happens when playing the CD and also in standby (CD not playing but unit is switched on). Crackling sound happens on both channels.

2. Crackling sound different on both channels.

3. It is able to track CDs, able to read ToC. I can hear music behind the crackling sound.

Possible issues:

1. PSU caps are faulty
2. SAA7030 is faulty
3. TDA1540 is faulty

Judging from the symptoms, what is likely to happen on this CDP?

I am struggling between DIY or sending to a local repairman. I would like to try to DIY the caps change. I have basic soldering skills, having soldered components to a PCB board for hobby projects.

I also read that the Philips blue radial caps that should not be replaced. How do they look like? Are they electrolytic caps? Are they also found on the PSU stage? I hope to keep everything as original as possible. Thanks in advance!

 

[gmphadte]

Loose connection due to cracked solder. Resolder areas at and near hot parts where heatsinks are located.

Gajanan Phadte

 

[sweat100]

An update, I have changed the all the electrolytic capacitors at power supply stage. The problem is still the same with the crackling noise. I have read that the problem can also be due to the voltage regulators (LM317 and LM337T) or some diodes.

Now I am not sure what is the sequence to diagnose this problem. I have come out with a list of plans but not sure what is the proper order to proceed.

1. Resolder all the PCB joints (Do I have to remove the old one and reflow the new ones?)

2. Replace all electrolytic capacitors on the PCB

3. Check the voltage regulator power supply

4. Anything I should do other than the above 3?

Advice is greatly appreciated.

 

[poynton]

As the crackling occurs in standby, I would suggest that the output muting is at fault.
The relays are known to fail.
It may also be a power fault to the muting circuit.


Andy


.

 

[srimok]

have u fixed the crackling sound issue?

 

[audiocats]

check the circuit board and see if there is any scorch marks, if opamps overheated they can make that kind of noise.

 

[isitrisky]

An update, I have changed the all the electrolytic capacitors at power supply stage. The problem is still the same with the crackling noise. I have read that the problem can also be due to the voltage regulators (LM317 and LM337T) or some diodes.

Now I am not sure what is the sequence to diagnose this problem. I have come out with a list of plans but not sure what is the proper order to proceed.

1. Resolder all the PCB joints (Do I have to remove the old one and reflow the new ones?)

2. Replace all electrolytic capacitors on the PCB

3. Check the voltage regulator power supply

4. Anything I should do other than the above 3?

Advice is greatly appreciated.

If you haven't done so yet, I would start with changing the 100uf/25v cap on the power supply board first then test it. this solves a lot of problems. Also, the large value caps are usually fine, there are a few 22uf/25v that need attention. As always, do one thing at a time and make sure to place em in with the correct polarity.