CD reading probs for Berendsen cdp1 - diyAudio
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Old 24th May 2011, 03:36 PM   #1
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Default CD reading probs for Berendsen cdp1

Hello Audio Experts!

A couple of years ago I took a chance on a used cdp, the rare & highly acclaimed Berendsen CDP1. It even has an upgraded cap or three. Really, really, sounds great!
But now it is having trouble reading CDs, mostly my CD-Rs but also with store-bought CDs sometimes. It most always will take lots of time to recognize a disc. It is getting worse....
So from my readings it looks like the laser pickup might be weak. I opened the machine & greased it up & adjusted the laser power. No better. So I assume it is time to replace the laser. I think I found the right pickup, & this looks to be a fairly easy thing to do providing there are no tricks which I don't know about.

Am I barking up the right tree? Is this as easy as throwing a bone to a dog?

TIA! Murf

PS: So like I opened my cdp, and to see what was happening better I took off the plastic crossmember that goes across the transport tray & holds the magnet disc which would sit atop the cd & mates with the drive spindle when playing . With this removed, all CDs play, even CD-Rs! If I put it back on, even without tightening the screws down, no play.
Um, ideas, please?!?!
pls...pls...pls....
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Old 24th May 2011, 10:18 PM   #2
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Default The machine changed it's mind...

Now the cd tray won't stay closed with the top magnet off of the spindle. The machine with the magnet on is now reading only redbook, no cdr's at all.

Murf
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Old 25th May 2011, 07:49 AM   #3
Mooly is offline Mooly  United Kingdom
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I've never heard of this player... what mech and pickup does it use ?

Pictures maybe ?
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Old 25th May 2011, 01:31 PM   #4
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Default Hi Mooly,

The machine is pretty much the same as a GamuT, if that helps. DAC is a Crystal cs4290, laser pickup is an 'OPC-A15', I can't find any ID for the transport, on the web but it has #s GM9350, & what I figure to be the control board has Samsung chips, but no adjustment pots.

Thanks, Murf
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Old 25th May 2011, 04:56 PM   #5
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Boy, I sure don't see $2000 retail in that chassis!
Looks like a Sony loading mech, but pickup # doesn't coincide. A photo with tray open & clamping support removed would help. From description, sounds like it's possible, assuming not a weirdly bad platter motor, that the probable cause is that a "press-fit" platter has slipped on the motor shaft, giving wrong focus distance. Generally, if you roll the laser to innermost position, the bottom edge of platter is usually about 1mm or so above the top of the laser plastic cover, so that cd surface is 2-3mm above lens. Just ballpark figures there, but an easy check to make.
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Old 25th May 2011, 06:24 PM   #6
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Default pics...

The laser lens looks to be ~ a mm below the platter.
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Old 26th May 2011, 03:18 AM   #7
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Not at all sure, but I would guess that it is a Samsung laser(seems supported by presence of Samsung chips), very much in imitation of a Sony KSS213 type laser(though unlikely a drop-in replacement) and it's mech. The loader is a dead ringer for a Sony mech, if it's not the real thing. However, I can't at the moment think of another likely cause for the symptoms you are experiencing.
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Old 26th May 2011, 06:20 AM   #8
Mooly is offline Mooly  United Kingdom
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I can't come up with much either I'm afraid.

A scope check of the RF signal is really what is required as it reveals so much.

Could it be a weak spindle motor ? as it played without the weight of the clamp (if thats what you mean). A trick that sometimes works if only to prove something is to apply a 9 volts battery across the motor for a few seconds to "burn" and clean off dirt on the commutator. If you try that you must isolate the motor electrically first.
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Old 26th May 2011, 01:51 PM   #9
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It seems my laser does work. BUT, it is not reading CD-Rs, and it looks like the previous owner had adjusted the laser power up. The control board (?) has no adjustment pots, so I figure this stuff is working well. The laser pickup goes in & out, up & down.

Murf
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Old 26th May 2011, 02:09 PM   #10
Mooly is offline Mooly  United Kingdom
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I think all you can do is try another pickup but without detailed scope checks it is a guess in the dark.

CDR's vary enormously in how "good" the recovered signal is and are dependant on discs and the CDR burner used... again the scope confirms what is actually happening.

You need to ID the pickup too.
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