My 5 disc player has started to skip the first three tracks on the CD, doesn't matter which disc it is. Any ideas as to where I should start looking to solve the problem?
Never worked on one of these but checking the sled assembly would be a good start. Make sure its free and that there is no old/hardened grease on any gears related to the sled.
Also check the RF quality with a scope. That should be part of any basic first test on a player.
If you can find no obvious reason then monitor the sled drive voltage during play. If it climbs steadily and then drops back as the sled jerks and skips forward then that's a good sign of mechanical problems (sled not free)
Also check the RF quality with a scope. That should be part of any basic first test on a player.
If you can find no obvious reason then monitor the sled drive voltage during play. If it climbs steadily and then drops back as the sled jerks and skips forward then that's a good sign of mechanical problems (sled not free)
The sled definitely jerks and skips forward when playing, I saw this when I had the cover off watching what it was doing.
First steps then would be to confirm that the mechanics are 100% OK. That means removing and dismantling the sled assembly and cleaning it all up and relubricating with a suitable grease (I've never worked on one of these so can only give general advice). Old grease can harden, get contaminated, or deteriorate and get what are like small granules forming in it... these cause the small gears to jam momentarily, when the servo increases the drive then the sled jerks forward.
There may be other issues at work but you have to confirm the mechanical side of things is good first.
There may be other issues at work but you have to confirm the mechanical side of things is good first.
Ok, I will remove the sled assembly, clean it up and re-lube. Any recommendations on the type of grease I should use?
Best way I've found is to use a bit of IPA (isopropyl alcohol) on a cotton bud for cleaning, then re-lube with silicone grease as this won't harm plastics/rubber. Don't use mineral oil or grease based on this. I've not worked on your make of cd player, but my Marantz has had the same problem in the past and it's down to old/dried grease building up on the slider rod that the laser tracks along.
I will give it a shot and report back. The player is 19 years old and probably has never been serviced by the PO.
The stuff I use is a special plastic/metal compatible grease,
Contact Lubricants - Other - Special Plastic Grease - SPG | Electrolube
Silicon lubes are fine as long as they are not to sticky and viscous.
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Well I took the case off today and it looks to be a tracking issue with the horizontal toothed unit attached to the eye. As it tries to play the first track, the noise I am hearing is the gear on the right side teeth slipping as it is trying to move left, but hits a square clear plastic button below the metal frame. The square button is spring-loaded from what I can tell. Sorry, I don't know the technical names for these parts. So I presume that there is an alignment issue?
Here's a picture of what I have been talking about😀
Here's a picture of what I have been talking about😀
Make sure the teeth are clean and don't use any lubricant as they are made from self lubricating plastic. You will probably find, knowing this assembly, one of the teeth is bent or there is some fluff/debris on the feed cog.
Teeth are clean and unbent. It is like the unit wants to index further to the left but runs out of room to do so.
The two large gears should just push and clip onto their respective shafts. With them removed then the sled should feel free and smooth if you manually move it along its slide. Photos can be hard to interpret. Is the lens really clean ?
With the gears in place and the tray closed it should still be possible to push the sled gently. It should be 'free' and not have any obvious sticking points.
The part you are describing sounds like the 'end limit' microswitch. When the tray is closed the sled moves back until it hits and closes this switch. Its how the thing knows where the disc start position is. Crude but it works, and its a universally used method.
With the gears in place and the tray closed it should still be possible to push the sled gently. It should be 'free' and not have any obvious sticking points.
The part you are describing sounds like the 'end limit' microswitch. When the tray is closed the sled moves back until it hits and closes this switch. Its how the thing knows where the disc start position is. Crude but it works, and its a universally used method.
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