Philips CD207 CD player over-revving?

Hi. I've just unearthed my vintage CD207 player from the loft, which is where it's been stored for years since it went faulty, preparing to chuck it out. To my surprise, it worked - for a few days, anyway. Now it is faulty again, so the problem seems to be intermittent - a dry joint maybe. The audio sounds fine. The problem seems to be with the motor drive. This revs up a couple of times when first switched on (its normal behaviour), but then runs continuously instead of stopping. If a disc is mounted first, it will spin out of control. I read an earlier post about a CD207 owner having problems with dry joints. Although I have a service manual for the player, and can wield a soldering iron, if I am looking for a dry joint I don't really know where to start looking, and could do with some guidance. Can anyone help me out, please?

Reply to
losinj
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Your information is too vague. There are literaly many hundreds of solder connections, as of many of them can cause your unit to not work.

Proper troubleshooting would be necessary to service your init.

The first thing to look for are visual faults, such as visible cold solder connections, and or broken parts, burned parts, or bad connections.

The next step is to verify that all the power supply outputs to the various areas on the boards are working properly.

The final step would mean following it through with a DVM, and a scope, to follow through the signal processing.

Jerry G. ======

Reply to
Jerry G.

That can happen when it loses the signal from the laser.

Reply to
ZZactly

Thanks for the tips. I was able to look over the PCB connections with the aid of an watchmaker's eyepiece, and resoldered a few that looked a bit suspect (I couldn't tell you which ones though). Thankfully, the player is now working again, so maybe that was the problem.

Reply to
losinj

On 19 Mar 2005 12:30:37 -0800, "losinj" put finger to keyboard and composed:

The very early Philips/Marantz players had double-sided PCBs. A common problem was dry joints at the thru-holes, especially those connected to the ground planes. IIRC, the motor could even spin backwards when these faults were present. The most reliable fix, as implemented in later models, was to fit pins to each hole.

- Franc Zabkar

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Reply to
Franc Zabkar

Have you considered that the disc might not be clamping properly, or do you have the drive opened to where you can observe it's operation? Improper clamping will often result in severe, irrecoverable disc wobble, which in the case of some players can be corrected through readjustment of the arm assembly, along with a great deal of trial and error tweaking. I have used this method successfully on a few players I.e. NEC CD-510 IIRC which is similar to some late 80s Sony models I've owned. If you can believe the disc actually running BACKWARDS from the friction of the poor contact, you can believe a lot of things, I suppose.

Good luck in your repair efforts!

Reply to
Steven

On Tue, 29 Mar 2005 07:16:15 GMT, "Steven" put finger to keyboard and composed:

I'm not the one having problems. In any case, *my* Philips/Marantz player *did* spin backwards, and it *was* due to dry joints in the earth connections between the top and bottom sides of the PCB. Believe me, you don't forget something like that. In fact I confirmed the open circuit(s) with a DMM.

I now have a Philips CD104 (aka Marantz CD44A) CD player which has the same type of PCBs, but which has pins in each thru-hole. The turntable motor control circuit consists of an MC1458 dual opamp (+/-12V supplies) and a push-pull NPN-PNP transistor pair (+5V & -6V supplies). One end of the motor is grounded, the other is connected to the push-pull emitters. With this kind of circuit it is quite possible for the motor to spin backwards in the event of a logic failure.

- Franc Zabkar

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Reply to
Franc Zabkar

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