Dead Philips CD200

[dzseki]

Hello to all,

I wanted to upgrade the output op amps in my Philips CD200 player, but after the mod the player doesn't work anymore
At the first testing it didn't read TOC, and one of the relays started to buzz, Then I checked if everything was connencted right, angain buzzing, after two more power ups it is not even buzzing anymore. It seems that the MAB8410 B002C went bad since it runs hot short after powering up.
Is there any way to get this IC or can I arrange the funeral of the machine?

[seebert]

dzseki: I am not a tech in any way but if you can't get a part in Hungary and need a friend here in the USA to ship you one at cost just let me know. Same goes for any other parts you can't source in 'Pesht. Best regards, Mike.

[dzseki]

Thanks for the offer, I really appreciate that!
But I'm affraid if I even find a source then it will be insanely expensive. But hope someone has one in the drawer

[amc184]

I think you're jumping to conclusions a little bit fast when you blame the issues on the MAB8410. You could be right, but I'd check a few more things first. Also, keep in mind that a MAB8410 is a mask programmed microcontroller, so you'll need one with the right program.

The first thing I'd be checking is all the power supply rails for both level and ripple. Buzzing relays make me suspect that one of the rails may be extremely noisy, and the relay coils are driven by the same 5V rail as all of the player's logic ICs. You're best off looking with an oscilloscope, but checking with a multimeter on both AC and DC ranges may do the job.

If you haven't already got the CD200's service manual you can download it from here.

[dzseki]

Okay, I did some further measurements. The supply levels and ripple are right, but it turned out that the pin3 (clock in (or out?)) of the MAB8410 is short to the ground, I guess it is not normal. :/

[amc184]

That clock line is part of a bus linking the decoder and servo PCBs. The data and clock lines both need to be pulled up which is done on the servo board. I'd check both the cables this bus runs on and the 5V supply on the servo board.

[dzseki]

I pulled out the MAB, since it is in socket, the ic itself is the short. Also when I pull out the ic, and power up the player the 15 leds are lighting, if I put back the MAB even if I disconnect the +5V of the decoder board the 15 Leds are not lighting. I measured the clock leg of the connector which goes to pin3 if the ic is not in the socket there is a certain signal, but with the ic in there is nothing.

[amc184]

Yeah, sounds like it definitely is the MAB8410. I think I've got at least one spare, but I doubt it'll have the right program. The only source for that IC is probably people breaking up this model of player, and maybe some of the others that use the same board set.

[dzseki]

Well, I have the MAB8410 B002C, I think the B002C identifies the burned in programme code, so if you have a spare B002C ending ic, then I think that would do the job.

[pdul]

First try to trace your way back in whatever changes you made, maybe a bad solder or a short somewhere. It is not normal to kill a microprocessor simply by changing an opamp.