Marantz CD 53/63 problems

[pzogal]

Hi all,
I am fairly new to this great forum, it's a really big source of wisdom Anyway, I have recently bought an used CD 53 off ebay for mods & tweaks. First thing I did was unsoldering the dc caps and mute transistors. Improvement was noticeable. Next was damping with bitumen pads. I am still waiting for opamps & stuff, but I've got a prob with skipping and the end of a CD. This happens mostly near the outer rim -> like last 10mins of 74min CD. I cleaned the lense with isopropanol , no result . Then dissasembled the pickup cleaned the old grease and regreased the shaft and the gears. The result: faster seeking but still skips. Any more tips ? How about increasing the laser current ? Or do I have to buy a new pickup ?

Greetings,

Pawel

[Thomo]

Hi Pawel, it sounds to me like you'll need a new laser.

Check out this thread for modding and tweaking info.

I think you'll be pretty amazed at the level you can take your player to.

Regards, Lee.

[pzogal]

Hi Lee,

Thanks for your answer.
this thread was the "ignition" to buy and play with the CDP Well, I haven't read ALL posts but MANY . I came across some info that one shouldn't use say "normal lube" but some kind of teflon or silicon stuff. I may try that as well + the trim pot. Anyone has experience altering the trim pot on the pickup pcb ?

Greetings,
Pawel

[jives11]

You may find that some players cannot play the out edges of very long CD's. I have had a CD Transport which had trouble with CD's longer than the orange book spec, which I *think* is < 70 mins.

[pzogal]

I played a bit with the trim pot yesterday but without success. I also investigated the symptoms a bit more. On one CD at track 11 (around 60min) there were big problems, the laser couldn't keep the right track, it was sort of vibrating trying aparently to realign. On the next track however it was better but still those oscillations. After cleaning the CD which I bought 2 days ago it was better but after some time it got back worse. I am tending towards a new CDM12.1 or VAM (whatever) unit.

[pzogal]

Hi all , I replaced the pickup yesterday but it didn't help any further ideas what could it be ? Some servo defects or ? Or maybe it just wont play some CDs ? Again, it has problems at some specific disc motor speeds.

Greetings,
Pawel

[kevinkr]

Make sure that nothing is causing binding at the outer edge of the disk - I'm assuming that this unit** uses the older style swing arm and vc actuator assembly and not a rack and pinion as found in the newer models. Make sure that any cables or ribbons are not binding at the outer edge of the disk, and that there is clearance to surrounding mechanism components at the maximum extent of travel.

I had a similar problem with a Sony (rack drive) and the solution was some careful work on the rack itself to remove some flash near the very end of the rack that caused drive gear binding.

Sounds like a mechanical problem - look for the cause of interference and fix that. Don't twiddle the pots!

**It's been about 10yrs since I last looked inside a CD53 or 63 so I no longer remember the exact details.

[poynton]

Originally posted by pzogal
............ Then dissasembled the pickup cleaned the old grease and regreased the shaft and the gears. .............

The recommended action here is NO GREASE.

The gears and mechanism should be carefully cleaned to remove all traces of grease. Do not regrease. ( This should also be carried out on new mechanisms )


Andy

[pzogal]

Thanks for all the answers, I doubt if the problem is mechanical one. The behaviour is the same with an old cdm12.1 and a new vam1202. It just starts to wobble on some tracks (with rather slower angular speeds) , in the end it begins to skip. Seems to me a focusing/tracking problem. I looked also at the connections between the diodes and the servo chip and it looks ok.
There is an interesting thread here and it seems that the philips player uses the same chips/parts:

Philips CD720 (CDM12.1) beginning to skip

Similar prob but no solution
Could it be something like with CD6000 as described in:
Marantz CD6000 "ERROR" messages - Help!

Could it be the hf amp ? How about aged electrolytics ? My CDP is from 1996.

Greetings and thanks in advance for further hints
Pawel