absolon
Super Member
Today was a good day:thmbsp:
I've been playing around trying to optimize a couple of old Philips CD160 CD players. These are equipped with the TDA1541 DAC and CDM2/10 transports and are fertile ground for upgrades. The transports use Hall Drive motors, are very durable and generally read anything; some consider them among the best ever made. The lasers can fail with age and wandering component values and since the CDM2/10 mechanism is no longer available, repair is problematic when they give out.
The laser on one of my decks finally quit leaving me with a non-functioning project. I have a Magnavox CDB500 that had a chip failure but had a still functioning CDM4/19 mechanism. The complete CDM mechanism is physically different enough that it wouldn't fit and doesn't use the Hall Drive spindle motor so the pre-amplifier PCB is not electronically compatible anyway but I had read that the laser pinout and flex connector were the same so the laser might be compatible. The lasers and their housings are of different configuration so it is not possible to swap the laser diode and housing alone. I have read of a possibility that the diodes are the same and could possibly be interchanged with a delicate operation, but that will be plan B.
The swing arm is a slightly different configuration ( CDM 4/19 on the left, CDM2/10 on the right) but dimensionally close enough that a replacement seemed possible.
As it turned out, it did fit the arm mount but there was a point of interference with the mechanism housing (circled on the photo) that prevented the arm from moving the laser far enough in on the disc to read the TOC.
I took a small razor saw and a diamond burr on a Dremel and carved out a notch to allow sufficient clearance for the arm and laser to move in enough to read the TOC.
After reassembly, the deck could and did read a disc so I was able to readjust laser current adjustment pot to give the appropriate reading of 50mV across the test points from the 90 mV which was likely the cause of the original failure. Put it back in the system to test and it works like a champ; it reads the disc and starts playing in just a few seconds. Can't yet speak to the durability of the repair, but I see no reason why it should fail now with fresh caps on the board and correct adjustment.
I've been playing around trying to optimize a couple of old Philips CD160 CD players. These are equipped with the TDA1541 DAC and CDM2/10 transports and are fertile ground for upgrades. The transports use Hall Drive motors, are very durable and generally read anything; some consider them among the best ever made. The lasers can fail with age and wandering component values and since the CDM2/10 mechanism is no longer available, repair is problematic when they give out.
The laser on one of my decks finally quit leaving me with a non-functioning project. I have a Magnavox CDB500 that had a chip failure but had a still functioning CDM4/19 mechanism. The complete CDM mechanism is physically different enough that it wouldn't fit and doesn't use the Hall Drive spindle motor so the pre-amplifier PCB is not electronically compatible anyway but I had read that the laser pinout and flex connector were the same so the laser might be compatible. The lasers and their housings are of different configuration so it is not possible to swap the laser diode and housing alone. I have read of a possibility that the diodes are the same and could possibly be interchanged with a delicate operation, but that will be plan B.
The swing arm is a slightly different configuration ( CDM 4/19 on the left, CDM2/10 on the right) but dimensionally close enough that a replacement seemed possible.
As it turned out, it did fit the arm mount but there was a point of interference with the mechanism housing (circled on the photo) that prevented the arm from moving the laser far enough in on the disc to read the TOC.
I took a small razor saw and a diamond burr on a Dremel and carved out a notch to allow sufficient clearance for the arm and laser to move in enough to read the TOC.
After reassembly, the deck could and did read a disc so I was able to readjust laser current adjustment pot to give the appropriate reading of 50mV across the test points from the 90 mV which was likely the cause of the original failure. Put it back in the system to test and it works like a champ; it reads the disc and starts playing in just a few seconds. Can't yet speak to the durability of the repair, but I see no reason why it should fail now with fresh caps on the board and correct adjustment.
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