Poineer PD-M430 skipping issue

[macman007]

I have cleaned the accessable part of the laser (top not underneath or in between) and tried various Cd's to no avail. It skips, distorts somewhat, tracks poorly and sticks like it's a dirty cd, but no matter how I adjust the 3 transport/laser pots it only gets "marginaly" better, not worth mentioning. Other than replacing the transport, (not worth it - shotgun guess) are there any known issues I can address to correct the issue?

My McIntosh MCD-7000 with the CDM-1 transport did the same thing when it went bad,.. after around 45 minutes of playtime. I lucked out and found a NOS one as the CDM-01 laser from Phillips is now unobtanium. That one is now as good as it was when I bought it new. I replaced that transport myself as a unit. It was a McIntosh so, to me it was worth repairing. It took over a year to find a NOS transport and cost 400 bucks because it is now so rare.

The Pioneer does it all the time cold or warmed up on any track or disc or position. Not being a cd guy repair wise, I would entertain any suggestions to possibly repair it myself. If not, I will be looking for a comparable used unit, but not necessarily Pioneer.

The unit is thoroughly clean with no loose belts or gears I can find. Perhaps this one has just given up the Ghost? *bigthumbdown*

I like the sound of the unit for a pld Cd player, smooth, warm and detailed, but if its a gonner I wont shed any tears, I just hate to have to spend money to buy a new/used player at this time. Not in my budget these days. *fit*

I'm sure it will only get worse not better. *hypnot*

Thanks to all in advance. All advice is greatly appreciated. *bigthumbup*


BTW, It happens with the 1 or 6 disc carts installed and playing 1 or multiple discs in the cartridge.


Phil

[Warped Bezel]

Have you ever seen this site?

http://www.repairfaq.org/sam/cdfaq.htm

[Skywavebe]

Hi Phil,
CD players are a technology upon itself. They should not be messed with by anyone as there are critical setting in there that if adjustments are made could stop the unit from working altogether. Besides that you need to have an understanding of what is causing what and the thing to do about it.
I have some broadcast type CD players on the bench now and they were having the same issues of skipping. Skipping is caused when the laser position can not be reached and the pickup lens can no longer "aim anymore sideways" to get to the track it needs. This is usually caused by lack of the tracking motor to be able to move either by frictional issues of a dirty worm gear or non- lubricated rails of a linear system. Cleaning the worm gear and the oiling of the motor or replacement at times of the sled motor might be needed. Now day without an original part and a lot of sled motors are unique, the unit may have limited future life. The pots on the pickup are laser power and that needs to be adjusted with a laser power meter- I have not seen one for a long time. Turning those up will cause the laser to burn out early and no laser- means no more output. The power of a laser without the proper meter can then be adjusted by the use of a scope on the EFM or Eye pattern test point with the use of the service manuals and knowing what the specified output is suppose to be. This requires a scope and the knowledge to use it for CD player purposes.
I have repair many CD players in my history and they can be perplexing at times. There are also widely defective optically defective discs out there too. You might come across one that just skips on a certain track. I had one and it was found out by watching the eye pattern and the behavior of the unit. Every disc of the same name of that pressing was a defective disc- he only tried three.

[macman007]

Thanks for the quick reply Sam, I will look into lubing the motor first and more cleaning of the laser itself, then more serious measures or replacement of the unit if this yields no results.

Phil

[Squank]

What are you using to clean the laser?
May I suggest to stay clear from pure alcohol, try glass cleaner, I use AZAX and you can clean the cd's with it too with great results.

[Pacific Stereo]

There are several possibilities here. What kind of skip is it? Does it skip forward or get stuck?

The first cause can be mechanical. Binding in the mech somewhere, or a dead-spot on the feed motor.

Alignment is a good possibility- these old players are, well, OLD. These Pioneers can be difficult, because the diffraction grating may need to be adjusted. This is nearly impossible without the eccentric tool. Test discs like the Philips 5A can make this job significantly easier. Skipping can be related to E/F balance, diffraction grating misadjustment, tracking offset and tracking gain.

The third cause is the optics themselves or some sort of trouble in the servos or power supply.

Cleaning the lens is always a good place to start. Use some canned air, and blow dust out from around the objective. If you can get the plastic cover off (it should pry off, remove it when you blow air into the head. Dust can get underneath and not be removed because the cover is in the way. Next, clean the lens with a Q-tip and either pure ethanol (Everclear) or vodka (BTW, vodka is a perfect cleaner for CDs). Soak the swab in solution, and start at the center of the lens and work in a clockwise spiral from the center out. Then, before the alcohol dries, dry the lens with another swab going counter-clockwise from edge to center. Last, blow again to remove any fibers you may have left behind.

Mechanical trouble is another possibility. If the mechanism binds, the player will tend to get stuck. If there is a dead spot or a place where the mech slightly binds, the player will tend to blast forward. Skipping all over the place, rapid skipping forward or loss of focus and/or high speed disc spin (like, centrifuge fast) is always alignment or optics.

A good test to see if you might have some binding or a bad spot on the motor is to hang a scope on the feed motor positive voltage drive. Put the scope in DC mode. You will see the tracking error signal superimposd on the feed motor drive. This will look like oscillation around an average DC voltage. In a normal player, as the disc plays, you'll see the average DC rise, then it will decrease and go lower. The level will slowly rise again, and then it will suddenly decrease again. The motor should turn at some voltage below about 2 volts. If it does not, what you'll see is the average level rising and rising and rising, and then it will either limit out (and the player will stick), or it will suddenly decrease and the player will skip forward and then play some more. In the first case, the problem is likely mechanical- debris in a gear or a spot where the mech wants to bind hard (wires can do this, sometimes). In the later case, it could be a "light" bind or more probably, a dead spot in the feed motor. Voltage builds and builds until it can break through the crud and then the motor turns, but way too much and too fast for the head servo to control for.

If mechanical is not the problem, them alignment is the next step. Absolutely impossible without a manual (unless you've done a zillion of them) and possibly specialized tools and/or circuit jigs.

The last step is new optics. Atmospheric crud can coat the optical path in a light haze, and there's not much to be done about this.

[macman007]

The laser mount tabs are bent and twisted, not allowing the cd to center itself when loading and reading. It looks like someone jammed something into it (kids or wife?) and bent and twisted the chassis mount and all 4 mount tabs. At this point I can see no way to straighten the frame tabs that hold/ center the laser assy properly, plus the motor is noisy in spite of lubrication, probably due to the excess misalignment.

In the bin it goes - file 13.

Anyone got a spare cd player for sale cheap? It doesnt have to be a Pioneer. This was a hand me down anyway, so I got my moneys worth.

Free 6 disc Pioneer cartridge available, works in home or car!


Moving on..Moving on...*flame*