SSLtech
Well-known member
Rakka-fakka-rikka-shakka little pieces of.....
I'm posting this in case any of you owns one of these time bombs... I have about twelve of them on my bench for repair. Just about every single one has the same problem. Worn-out spindle motor.
Symptom:
"Cannot recognize disc". -Lifting the top cover off and watching confirms this particular problem by the fact that the disc spins weakly, or not at all.
Fix:
Replace spindle motor. HA!!! -Good luck! -You can't buy it onit's own. It's only available as part of the assembly (of which there are several variants with differing focus mechanics/laser assemblies/mounting details/cable exits/pinouts...) most of which cost as much as a new DVD player.
The *DIY* fix: :green:
remove the spindle motor from the laser sub assembly. The motor in question will likely be marked RF-320CH-12400 and is a Japanese DC affair made by Mabuchi. The orientation of the positive terminal needs to be marked before desoldering the two terminals from the flexible PCB. Also, to get the two mounting screws off, the turntable platter needs to be pried off. Start by noting the height of the platter above the deck plate. make some sort of "feeler-gauge" so you can re-install the platter at the correct height later: this is vital for focus purposes... then pry the platter up & off, with a small-ish flat balde screwdriver, but keeping very close to the spindle, otherwise the leverage can bend the shaft...
Okay, with the motor removed, you'll need to find another mabuchi motor with the same size body, but one that isn't run continuously like a spindle motor is. -I found a couple of dead TASCAM CD players which use them for loading motors... different voltages, different rotation directions, different speeds, but no matter... they have what we need...
Accurately mark the position of the positive terminal on the bodies of both motors. Starting with the Sony motor to be repaired, get a pair of side-cutters... (*NOT a good pair... a 'sacraficial' pair) and pry apart the four 'crimps' that hold the bottom plate of the motor on. This might take a couple of tries to get right...! When all four are pried apart sufficiently, you should be able to pry the bottom plate off with a small screwdriver, at the little slot in the body, usually near the negative terminal.
Pull off the bottom plate and look at the brushes. They'll be worn out and destroyed. Notice also that these's a nylon ring just below the commutator which can damage the brushes if ripped out carelessly... this didn't matter for this motor, but we want to keep the brushes from the other motor INTACT, since we're going to 'transplant' the brushes from the second motor onto our first, so figure out a way to push the spindle & armature out with the bottom plate when you do the second (brush-donor) motor.
Okay, once the endplate (with brushes) is carefully removed from the donor motor, take the armature/spindle assembly from the Sony DVD spindle motor, and carefully slip the back end of the spindle into the bearing on the back plate, being careful not to break the brushes with the nylon ring. Once in, slip the assembly back together, but make sure that there is something stopping the armature from being pulled out of your fingers towards the magnet as you push them together... you'll see what I mean... you can use a needle/screwdriver through the motor top bearing, or from the side, holding back against the nylon ring.
When the assembly is back together, (check the positive terminal location!!!) tap the four crimp points back over lightly (you don't have to be obsessive about it... it's not going to come apart!) and reasemble the laser/spindle assembly, being careful to replace the platter back on at the right height.
That's it...
Now I've got dozens of these things to do.... Grrrrr!
Just in case anyone has a SONY DVD player here... oh, and if anyone ever finds a source of mabuchi RF-320CH-12400 motors at acouple of dollars each, I'd love to know!!! -Otherwise, if you get a DVD player with a bad PSU or similar... SAVE THE SPINDLE MOTOR!!!
Keith
I'm posting this in case any of you owns one of these time bombs... I have about twelve of them on my bench for repair. Just about every single one has the same problem. Worn-out spindle motor.
Symptom:
"Cannot recognize disc". -Lifting the top cover off and watching confirms this particular problem by the fact that the disc spins weakly, or not at all.
Fix:
Replace spindle motor. HA!!! -Good luck! -You can't buy it onit's own. It's only available as part of the assembly (of which there are several variants with differing focus mechanics/laser assemblies/mounting details/cable exits/pinouts...) most of which cost as much as a new DVD player.
The *DIY* fix: :green:
remove the spindle motor from the laser sub assembly. The motor in question will likely be marked RF-320CH-12400 and is a Japanese DC affair made by Mabuchi. The orientation of the positive terminal needs to be marked before desoldering the two terminals from the flexible PCB. Also, to get the two mounting screws off, the turntable platter needs to be pried off. Start by noting the height of the platter above the deck plate. make some sort of "feeler-gauge" so you can re-install the platter at the correct height later: this is vital for focus purposes... then pry the platter up & off, with a small-ish flat balde screwdriver, but keeping very close to the spindle, otherwise the leverage can bend the shaft...
Okay, with the motor removed, you'll need to find another mabuchi motor with the same size body, but one that isn't run continuously like a spindle motor is. -I found a couple of dead TASCAM CD players which use them for loading motors... different voltages, different rotation directions, different speeds, but no matter... they have what we need...
Accurately mark the position of the positive terminal on the bodies of both motors. Starting with the Sony motor to be repaired, get a pair of side-cutters... (*NOT a good pair... a 'sacraficial' pair) and pry apart the four 'crimps' that hold the bottom plate of the motor on. This might take a couple of tries to get right...! When all four are pried apart sufficiently, you should be able to pry the bottom plate off with a small screwdriver, at the little slot in the body, usually near the negative terminal.
Pull off the bottom plate and look at the brushes. They'll be worn out and destroyed. Notice also that these's a nylon ring just below the commutator which can damage the brushes if ripped out carelessly... this didn't matter for this motor, but we want to keep the brushes from the other motor INTACT, since we're going to 'transplant' the brushes from the second motor onto our first, so figure out a way to push the spindle & armature out with the bottom plate when you do the second (brush-donor) motor.
Okay, once the endplate (with brushes) is carefully removed from the donor motor, take the armature/spindle assembly from the Sony DVD spindle motor, and carefully slip the back end of the spindle into the bearing on the back plate, being careful not to break the brushes with the nylon ring. Once in, slip the assembly back together, but make sure that there is something stopping the armature from being pulled out of your fingers towards the magnet as you push them together... you'll see what I mean... you can use a needle/screwdriver through the motor top bearing, or from the side, holding back against the nylon ring.
When the assembly is back together, (check the positive terminal location!!!) tap the four crimp points back over lightly (you don't have to be obsessive about it... it's not going to come apart!) and reasemble the laser/spindle assembly, being careful to replace the platter back on at the right height.
That's it...
Now I've got dozens of these things to do.... Grrrrr!
Just in case anyone has a SONY DVD player here... oh, and if anyone ever finds a source of mabuchi RF-320CH-12400 motors at acouple of dollars each, I'd love to know!!! -Otherwise, if you get a DVD player with a bad PSU or similar... SAVE THE SPINDLE MOTOR!!!
Keith
