Help needed with Philips CD 104

[grundigradioboy]

Hi,


I'm new to the forum. I was hoping someone here can help. I have a Philips CD104, the 104/65 B model, unmodified, owned since new in 1985. At about 2 years old I had an intermittent audio cut out problem, took a while to get it sorted, it was fixed eventually by a friend who was an RAF electronics engineer, he soon cured it once he'd got a copy of the service manual. He said it was a dry joint, so I assume it was one of the known griplet problems on the audio board.


It has been fine ever since, though I recently had to fit a new/secondhand loading drawer, as the belt driven pulley had lost 2 teeth off the inner pinion.


Now, however, I have a new problem. There is a bad connection on the servo board. Symptoms are that once it goes dis, the motor runs continually. It will not load TOC, and if it occurs while playing, it stutters then stops. Going into test/service mode, it will run the first 2 steps correctly, but step 3, (pressing “forward” for 2 seconds, it does not enter the mode until the fault clears. And that is how I know the fault is the servo board, for if I press down on the right hand side of the board a little, between the 2 cut outs designed to accommodate the front 2 chassis strengthening buttresses, (there are 3 of them), the motor will stop and then the machine will perform correctly. Question is, are there any known bad joints near there? I believe there are 2 “through” joints on this board, is one of them around here? Apart from this problem, the machine works perfectly.


I am determined to fix it, as the machine has been a loyal servant for so long, and I really like the build quality, sound and “history” of this model. I will admit I'm not a whiz with a soldering iron, so if it's not an easy fix, I'd be willing to pay to have it sorted by someone who knows what he's doing, or I'm considering getting a donor machine so I can swap the board out. (I have PM'd Bernhard, as he was selling soldered and tested boards a couple of years ago, am awaiting a reply) At least then I can sort it at my leisure. I'm in the Chester area, so, anyone in a position to help? Any suggestions? I'm all ears. I guess everyone here is, it's an audio forum after all.

Thanks in advance

Ian

[stephensank]

I'm sure this has been covered many times before here, but the biggest issue with this generation of lovely old Philips units is cracked ground plane solder joints, most particularly on the servo board. All you need to do is look on the component side of the pcb's for solder points that go through to connect top ground plane to bottom ground points. It's tricky to make an assuredly good joint on these, so I always advise removing the solder, installing a wire, bent over on top & on bottom, then soldering wire top & bottom. This will assure no future problems. You should also, of course, look for other cracked joints, especially in the area you've narrowed down to. From your findings, sounds like no dying capacitor problems yet, but would not be a bad idea to replace all of the non-Nichicon electrolytic caps with new Nichicons, for long term reliability, as well as better sound.

[poynton]

I cannot remember how many griplets there are but it is certainly more than 2 !!

They must all be resoldered with a wire through from one side to the other.

That is an essential MUST-DO before anything else!

Andy

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[grundigradioboy]

Thanks for thje replies guys, but like I said, I'm no expert at soldering. I'm also a "if it ain't broke, don't fix it" type, so through solder joints that are not giving problems can stay as they are, and as for swaping capacitors, I'd end up with a non-working piece of junk. My old adage, from DIY, is "know your limitations" and I don't intend to exceed mine. I'll soldIer on with tracking down the culprit, but if anyone comes across a servo board they'd be willing to sell, give me a nod!

[poynton]

Can you meet me in central Chester this Weds with your servo board?

I can fix it for you over Xmas.

Andy



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[grundigradioboy]

Originally Posted by poynton

Can you meet me in central Chester this Weds with your servo board?

I can fix it for you over Xmas.

Andy



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Should be easy, when and where?

[poynton]

PM sent

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