Help! CD platter just spins after changing op amp on Denon player...

[bermtoog]

I just replaced the JRC4558D on my Denon DCM-260 CD player with a TI NE5532P and that's all. I put everything back together exactly as it was and now the 5-disc tray/platter spins at a high rate of speed as soon as I plug it in and it doesn't stop.

If I disconnect the interface cable that goes to the tray, the display works and the drawer slides in and out when I push the "Open" button. As far as I can tell everything is normal but the tray. I can't figure this out, I've looked at everything very carefully and handled the PCB with kid gloves. Several of the capacitors are out of tolerance (1997 manufacture date) and I ordered all the electrolytics to do a complete recap but it worked fine when I took it apart and now it doesn't. Now I'm having second thoughts about taking the time to recap.

Am I forgetting something really simple? Please help!

Thanks
-Kevin

[purplepeople]

Maybe the V+ and V- connections are reversed.... by installing the chip rotated 180 degrees?

:)ensen.

[stratus46]

Did you have any static discharges into it while you were in there? If the humidity is low it's VERY easy to zap a logic device. Are any of the connectors in the wrong place or is it possible to reverse a connector? The molded plastic ones not likely but flexible PCB connections sometimes can be 'flipped'. Did you take photos of the 'innards' before you began disassembly? That's always an excellent idea.

G²

[bermtoog]

Purple: No, the op amps are installed correctly, thanks.

Stratus: That's immediately what I thought, it has been very humid here but it's still a possibility. It's just weird that all the other functions seem to work properly and I believe most everything is controlled from one primary IC with about 40 leads coming out of it. I marked all the connections that could be reversed before disassembly and the others are color coded and irreversible. Plus, you can tell because of the bends in them, etc.

You don't think it could be a ground issue, do you?

Thank you both for the replies!

[c2cthomas]

Perhaps this link to download the service manual will help. The problem is that many (including this one) CD/DVD players need to be tested with a disk that is provided by the manufacture.

Buuuuuut - what the heck - maybe you can find a clue in there somewhere?

DENON DCM-260 360 Service Manual free download, schematics, eeprom, repair info for electronics

Hope this helps.

[bermtoog]

Thanks Thomas, I really appreciate it. Just downloaded, now to troubleshooting!

[JonHarrison]

Clock signal not reaching the mechanism control ic ? I've seen this happen with another player using a SAA7310 decoder and Philips CDM-9 mechanism when you remove the clock. Your problem may be similar.

[bermtoog]

Thanks Jon, it's a good thought... I'm getting some really erroneous voltages on the terminal function IC so I'm pretty sure one or more of the IC's got fried, just don't what. This was more or less a test to see if I could improve the sound on a cheap CDP to satisfy my ears. Learned a tough lesson: static electricity sucks. I guess I'll just sell it for parts on eBay and try again with a grounding strap this time!

Thank you guys for the help!

[Mooly]

Zapped by static wouldn't be my first suspect tbh

I would guess far more likely to be a supply missing or a solder blob somewhere that you didn't notice while working on it.