I have a Philips CDM1MKII transport and after track 5, on any CD, the laser beggins to make an audible whining sound all the way to the last track. The whining goes away during the second, or so it takes to advance the track. It also goes away if I gently put some pressure with my finger on the laser head's swing arm while playing. It's a magnetic swing arm.
Any ideas on what may cause this? All help is greatly appreciated.
Any ideas on what may cause this? All help is greatly appreciated.
It moves perfectly freely. So the whine started yesterday and lasted all day. This morning it completely went away for an hour and now it's back again.
All electrolytic caps were replaced with identical new ones about two months ago and it was performing flawlessly.
Should I turn the focus offset potentiometer a bit to see what happens? I also have this service manual, it's a different CD player, but same transport: http://www.acousticpsychos.com/Files/Arcam/ARCAM-70.2-170-cd-sm.pdf
I'm assuming any high quality undamaged commercial CD can be used instead of test disc 5?
What you could do is buy a cheap CDM 4 based CD player and transfer the laser and see if that fixes the issue. When I adjusted my CD72 there were two pots to adjust the laser (focus and voltage). I downloaded the service manual and noted down the values before adjusting the pot. Officially you need a special CD, however a good quality ECM CD did the trick.
As far as I know you have a brushless motor so that can't be the problem (had to replace the spindle motor once).
No further ideas. How this will help you a bit.
As far as I know you have a brushless motor so that can't be the problem (had to replace the spindle motor once).
No further ideas. How this will help you a bit.
Okay, I followed Arcam's service manual and did adjustments for both laser and focus offset. The only two which can be adjusted. I've set the potentiometer/resistor combo to 1K and I'm getting 950mV, under the safe operating voltage of 1260mV.
Focus offset I started with potentiometer's position in the middle and then fine tuned to get 400mV +/-40 at TP27. Service position 2 is basically the middle of a CD, usually tracks 7/8. I've tested many CDs and consistently got 400-402mV. After about 20 CDs, I'm getting worst case scenario of 428mV at the start of disc and 394mV at the end.
Everything tracks and sounds great. The laser head is still making noise, but that's just the vibration the oscillating coil against the springy metal sheet.
However, nothing past track 2 on any CDR plays. It never played past 2 of any CDR, but is there a way to make CDM1MKII track them?
Focus offset I started with potentiometer's position in the middle and then fine tuned to get 400mV +/-40 at TP27. Service position 2 is basically the middle of a CD, usually tracks 7/8. I've tested many CDs and consistently got 400-402mV. After about 20 CDs, I'm getting worst case scenario of 428mV at the start of disc and 394mV at the end.
Everything tracks and sounds great. The laser head is still making noise, but that's just the vibration the oscillating coil against the springy metal sheet.
However, nothing past track 2 on any CDR plays. It never played past 2 of any CDR, but is there a way to make CDM1MKII track them?
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If I were you, I would carefully remove the screw and metal sheet (don't bend it! Just pull it gently while twisting). The ballbearing (two tiny metal balls on either side) should be cleaned and the old grease removed. Then apply some new grease (MG Chemicals Chemicals
US HTS:2710193500 ECCN:EAR99 COO:CA or self lubricating grease with graphite) on the bearing. Don't use Vaseline or turntable oil (vaseline too sticky and oil too thin). Put it back together and see if this does the trick.
US HTS:2710193500 ECCN:EAR99 COO:CA or self lubricating grease with graphite) on the bearing. Don't use Vaseline or turntable oil (vaseline too sticky and oil too thin). Put it back together and see if this does the trick.
Yes, every single cap was replaced. As the tracks are skipped forward/back, the noise goes away momentarily as the swing arm moves. As soon as it finds the track it comes back. It's also silent on tracks 1-5, but becomes audible at track 6+.
Are you getting 400-402mV on service position 2 on different CDs?
Beginning-to-end offset of 34mV is perfectly aligned swingarm.
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