My 20y? old NAD 502 has developed a problem: after closing the drawer, with or without CD, nothing happens. No spin, nothing. After a few seconds the drawer opens itself again. This problem increased over time and now the issue occurs all the time.
I cleaned the lens, with no effect.
Any suggestions what to do?
I know it’s not economical to spend much money and I’m not sure I would go down the route of exchanging the entire laser unit. However, there is some emotional value in the old NAD….
Thanks!
I cleaned the lens, with no effect.
Any suggestions what to do?
I know it’s not economical to spend much money and I’m not sure I would go down the route of exchanging the entire laser unit. However, there is some emotional value in the old NAD….
Thanks!
My first suggestion would be to see if the turntable motor has a voltage across it.
IE is the motor at fault or is it a servo issue ?
IE is the motor at fault or is it a servo issue ?
I'm not familiar with the NAD but are you sure the loading cycle is completing fully?
Thinking loading belts and microswitches here as your description of the fault would fit many makes and models where this was the problem. Microswitches can cause contact bounce and trigger opening of the drawer immediately it has closed.
Thinking loading belts and microswitches here as your description of the fault would fit many makes and models where this was the problem. Microswitches can cause contact bounce and trigger opening of the drawer immediately it has closed.
Thanks for the quick and valuable replies! I will check them all (in the next few days) and post the results.
@Mooly: the drawer does not open immediately after closing. It looks like it’s “waiting” for de spin-up and TOC reading. It opens after approx. 7 seconds.
@Mooly: the drawer does not open immediately after closing. It looks like it’s “waiting” for de spin-up and TOC reading. It opens after approx. 7 seconds.
It is highly unlikely, but not impossible, that it is an electronic board fault. Do look around the PCB for domed electrolytic caps. It could be a PSU fault.
Page 21 of the service manual has a fault finding guide.
Page 21 of the service manual has a fault finding guide.
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Mooly said:
This
Either the belt isn't up to much, or the loading switch is fubared
If you hook your finger in quick enough to help lift the mech to clamp just after tray load, then you'll probably find it'll finish load and then focus and spin up.
You could also turn off as soon as drawer shuts with a disc in, then turn the whole player on one end. and turn back on again, without gravity the mech should finish load and spin up if it's just a duff belt
You could also turn off as soon as drawer shuts with a disc in, then turn the whole player on one end. and turn back on again, without gravity the mech should finish load and spin up if it's just a duff belt
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Belt would be first suspect. Can you hear or detect the loading motor still spinning when you think it should have fully loaded?
The loading motor stops after the drawer is closed. I do not hear the disc-motor after that.
After this weekend I’ll put it on the bench and open it up for inspection of belt and switches. Thanks again for the replies!
After this weekend I’ll put it on the bench and open it up for inspection of belt and switches. Thanks again for the replies!
Another check that the loading is complete is to wind the laser (gently!) back away from the spindle motor a way..
If loading is actually completing succesfully the laser should then move in towards the spindle motor. (after that it'll do a focus search and on)
If loading is actually completing succesfully the laser should then move in towards the spindle motor. (after that it'll do a focus search and on)
Bump. Checked the player today and you guys were right: it was the belt!
I assumed this belt only pulled the drawer inside, but it also “lifted” the laser deck up when the drawer was pulled in. And there it went wrong: the laser deck did not fully lift because the belt slipped during that “lifting”.
Unfortunately I did not have any belts available so I cleaned it with some alcohol. That works for now.
Does anyone know how to remove the drawer so I have better access to the belt when I change it for a new one? The service doc is not clear on that (for me….)
Thanks!
I assumed this belt only pulled the drawer inside, but it also “lifted” the laser deck up when the drawer was pulled in. And there it went wrong: the laser deck did not fully lift because the belt slipped during that “lifting”.
Unfortunately I did not have any belts available so I cleaned it with some alcohol. That works for now.
Does anyone know how to remove the drawer so I have better access to the belt when I change it for a new one? The service doc is not clear on that (for me….)
Thanks!
I would guess just remove the two screws and lift the clamp off. Open the drawer first and then disconnect power, then gently look to see how the drawer is held. Usually little plastic tab/s that can gently be lifted out of the way. I've done hundreds in the past (like 25 yrs ago 😀) but can't just think to describe it. Should be pretty obvious if you look.
Hello, I have the same problem for some time now, my workaround is to use a toothpick and insert it in a small existing hole on the bottom of the unit, this helps lift the mechanism which then can pick up the CD.
Anyway, I changed twice the belt in it's life and I guess I have an alignment issue with the phase of the dented wheel that pushes the tray in and out. at the end of both in and out movements it makes a rattling noise as if it was trying to push further.
Does anyone have an idea how to position the tray in correspondance with the dented wheel to "synchronise" both movements? (the turn of the dented wheel and the dented track on the side of the tray).
Thank you very much for any information!
Anyway, I changed twice the belt in it's life and I guess I have an alignment issue with the phase of the dented wheel that pushes the tray in and out. at the end of both in and out movements it makes a rattling noise as if it was trying to push further.
Does anyone have an idea how to position the tray in correspondance with the dented wheel to "synchronise" both movements? (the turn of the dented wheel and the dented track on the side of the tray).
Thank you very much for any information!