Hello forum! I come back to you looking for help. As the title says, the focus coil of my D321 suddenly stopped working. The lens on the laser assembly stopped moving up and down. It moves just a little bit (it just sinks half a millimeter perhaps), but definitively not as much as it should. Hence, I assume that the player is unable to focus on the CD and read it. The problem happened from one day to the other: two days ago it worked like a charm, yesterday it stopped reading CDs completely. The palyer as not plugged to the wall nor to any other device. Hence "dead by over-voltage from the wall" is highly improbable. I've tried the usual troubleshooting without success: - Electrolytic capacitors are all replaced, specially the ones related to / on the traces providing power to the focus coil driver IC. - The problem happens both with AC and battery power. - I also checked the laser. It emits and its current values are healthy. - The sled moves back and forth without issues. The spindle motor is also healthy. - There is nothing blocking the lens from moving up and down.. It can move freely. - I ran the tests described in the service manual. The automatic tracking and focus adjustment do not work because, well, the lens is not moving and hence no adjustment can be made. The tracking adjustment throws no errors, it just keeps trying to adjust the tracking to no success. - The manual states that VCC should be between 3.2 and 3.25 V. I am reading 3.19V . Close enough I guess? AFAIK there are no potentiometers to adjust VCC. Therefore I would assume the value is OK. - Inspecting the laser assembly, I found nothing unusual. The focus coils seem OK. I have not tested for continuity on the coils. - I might have a replacement laser on my ''donors bin'', but I would like to discard any other possible root causes before switching the laser assembly. Any ideas or suggestions are deeply appreciated. I really enjoy this player. I got it a couple of months ago and it is in mint condition.
To repair the laser focus coil or inspect it to determine the root cause... this is all in Master Kaosun's specialty area. If cost is a concern then you may be better off swapping the laser assembly from another compatible CD player. However, since Kaosun can also check all other possible problems with the D-321 player and repair those at the same time, for a little more cost, it makes a great deal of sense to send it in for a complete overhaul. Is it worth it? Only you can decide!
Hi Hyperscope! I tried replacing the laser and the symptoms are the same. I suspect that something might be off with the driver. Oddly, the spindle and laser motors are both driven by the same driver, and those are working OK. I already posted my question at Master Kaosun's forum. Let's see what he recommends. In all fairness, sending the player to him to repair is a little over-the-top (specially considering that I am in Germany and the shipping comes on top). As much as I like my CD PDCPs, the sad truth is that all of them are +30 years. The fact that some of them still work is a thing of wonder on itself.
I was going to bet that changing laser won't solve the problem, but I see that I am too late for that. My next bet - once Kaosun responds to you Q it will be similar to what he said about D-66 Discman here: Recapp all SMT caps and further clean the leaking polluted areas. Every D66/Dt66 can be handled. Even if you do plenty circuit analysis, you'll find it's still problems related with caps and leaking. Be very careful of each operation. D-321 is beautiful, one of the last Sonys worth having. Velvety all-metal lid, an option to turn off that awful Electronic Shock Protection, nice grommets for the laser. But it is not the famous D-311, so reviving these makes sense only for your own collection. Here is my D-321 as received, cold-dead: Except for the four 47uF, all SMD caps leaked pretty badly. One example - land and via under C528 got damaged, connection to the driver MPC17A38V was restored by copper wire: recapped: yours will be different, all I can add is that hunting for those damaged traces and vias is quite difficult. I use Leica dissecting scope for the job and still usually miss a few spots on the first try
Hello Jorge! Thanks a million times for the detailed pictures. I kept running some test with my player and found out, that the focus coil does indeed work, but only if the player is sideways or upside down. In that case, the any CD on the player is read and played without issues. But as long as the player is upright, it is unable to read the CD. I realized that the focus coils can move the lens only downwards, but not upwards. I tested the laser on another player, and the coils worked OK. So that discards a damaged focus coil on the player, leaving only the traces or the driver itself. I could not find anything wrong with the traces, but all I could do was test for continuity with my multimeter. The C528 was leaking a little, but I could not see any considerable damage to the traces. I have replaced all caps, except the 47 uF (I am not skilled at soldering SMD caps, and those are tiny). Since I could see no damage on the traces, I started suspecting that the driver itself could be damaged, which would be a bummer since it is almost impossible to find a replacement (the driver on this unit is apparently very unusual). Your repair gave me new hope. I'll check the traces again and, just in case, will use thin enamel wire to connect the focus coil pins in the driver directly to the corresponding pins in flat wire connector.
Jorge, I prayed to the pagan gods of electronics for help, and they sent you with high resolution pictures. The same trace you repaired in your unit was also damaged in my player and I completely oversaw it. The repair was completely nerve racking. The hole you used to pass a wire from side to side is completely blocked on my playery so I had to use thin enamel wire to connect the pin on the driver directly to the capacitor pad on the other side of the PCB. Soldering the wire to the driver took a lot of time, several attempts and a healthy dose of swearing (I have no microscope unfortunately, and I was really worried of damaging the driver with my less-than-stellar soldering skills). But somehow I did it, and now the focus works as expected. As a matter of fact, I am listening to the player while writing this reply. Oh good fellow netizen, may your CD players live a long and healthy life!
