Nakamichi CD Player 4 - Won't Read CDs...

[k03a05]

Hi,

I have a Nakamichi CD Player 4, circa 1990. Some time in the last few years, it quit reading discs. When a CD is inserted, the tray closes, the CD turns about a half revolution, following by a couple soft clicks from the laser assembly.

I replaced the laser, no change, and have checked the two microswitches in the transport assembly, and they operate correctly.

I have seen several threads noting that these players quit reading, but have not seen any posted solutions.

Any ideas as to what the needed repair is?

 

[benricci]

Have you lubricated the transport sled? After 30 years, it might be dried out, causing the transport to be unable to move properly (it's a precision instrument and needs to be in good working order to function right).

The belt may also be worn, dirty or damaged. Again, after 30 years that's not unheard of.

Start with those two things and let us know what you find.

 

[k03a05]

Thanks for replying, ideal.

Yep, the transport slide works correctly, and all mechanical aspects are in good order and free of dirt.

After the initial half revolution of the CD, it simply won't spin the CD to read/ID the disc...

 

[onanysunday]

I'm not familiar with that model, and it's kind of a shot in the dark, but you may check/ replace any electrolytics on any board controlling the laser operation. I know you've already replaced the laser itself, but the problem could be in the board controlling the laser. Follow the laser assembly and trace its wires and connector to see where they go and which electrolytics may be nearby and in (possible) need of replacement. This has worked for me in the past when I had the same problem. Also, if you've accidentally bumped any potentiometers when in there, it could be out of adjustment- although less likely (depending). Don't touch the pots. Look at any perishables, like the electrolytics first. A picture of the laser board may help.

 

[thardie]

I have one of these. After many hours or troubleshooting, I found by heating the motor control IC (CXA1081S) which is closest to the CD tray even with a hair dryer or heat gun, it started to work. As a temporary fix, I put a 5W 3k resistor and powered it from the AC secondary side of the 12V winding on the transformer. It's center tapped, so going across both sides gives you a little south of 28V AC RMS. It only dissipates around 1/4 watt of heat, but that gets it up to around 30c in around 5 minutes, and tops out around 40C which was enough to keep it working. I put a 100ma fuse inline just in case, and used thermal glue to glue the resistor to the IC. Here's what it looks like:

 

[Kevviek]

Interesting. I have a DVD-10S which will often read discs only after it’s warmed up for 20 minutes or so. I might see if a heat gun will help it too.