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MCD7008 Horrible Distortion/Static

Aaaaand done...mostly.

Finally eliminated the noise, got all tracking working, and even somehow managed to do it so that when I put the cover back on it stayed good (kept reverting back for a while when I put the cover on). The new glass makes all the diff regarding looks since my old one was in a million pieces.

Now I just need whatever part goes behind the metal door trim and clips to the tray. Working with Gail now to figure that out. Door piece is just resting in the trim for the pic :)
 

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I just bought some Sony lasers from China for a whopping $8 each shipped for my 7008. I damaged one of the 4 I bought. I still have two more new ones. That fixed my 7008 and I didn't touch a single pot on the RF amp board. Now all I have to do is assemble it. In some ways I really like Ebay.

I suggest you replace the laser. They do wear out after a while.
 
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Yea thats what I did. I had to adjust the pot on the laser itself to eliminate the noise. The tolerance between noise and not working at all is so tiny it took me a good hour to find it...and then you attach some hardware and it throws it all off again. 4 hours later I finally had it tuned. Adjusting the RF Amp Board pots may have made it easier, but getting access to them is a pain so I avoided that.
 
I just posted my fix to the hints/kinks subforum regarding the distortion/noise that I was experiencing. All in all, it was fairly easy. I didn't have to remove the RF amp board to replace C213. Now it is solid and none of the controls are touchy and I didn't have to touch the laser output pot either. I just set the tracking gain and focus gain back to where it was to begin with and then adjusted the two pots on the RF amp board for max RF output. It actuially played with the two RF amp pots in the middle of their range which is what I would expect. All in all, it all just neatly fell into place.

How did I come up with C213 as the problem? I had talked to a McIntosh tech/engineer a few years ago and took some notes.

Drilling two 1/4" holes in the plastic side frame made access to the RF amp pots easy. Finding a suitable screwdriver was the hard part. I wound up making one but I am sure there is an Xcelite screwdriver out there that would work.

Richard - who is listening to Pink Martini's Xmas album and liking it.
 
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Thanks for the heads up. I'll try that myself.

Oh I also have a favor to ask. If possible, would you maybe be able to take a picture of the CD Tray door from above? Mcintosh sent me the metal faceplate for the door, but they are having trouble understanding that I need the part it attaches to and clips onto the tray itself. I want to send a pic of it to them so they understand what I need.
 
Thanks...and btw I left note on the hints thread but I wanted to say thank you again. Swapping out that cap eliminated all my lingering issues. Its now 100% alive again! I wonder what causes that specific cap to go bad.
 
The cause for the cap failure is anyones guess. I think the original was rated at 50 volts. I used a 63 volt. It should last longer.
 
Sigh...two new problems just cropped up...prolly since this is the first time the unit has been fully utilized for more than an hour...

The first is the bigger issue...when a CD is playing, and you switch to another CD...the laser moves forward and then the mechanism starts clicking. When I opened up the unit I can see that it basically is not getting the command to stop, and just keeps trying to move forward. I'm guessing the little blue plastic thing that bends back when the laser housing comes in contact with it is a sensor which tells the mechanism to stop...it is not tho. Any thoughts on this?

The second problem is when the tray is extended from the chassis to put a CD in, and then you press load, it tries to pull in the inner tray, but the support tray stays out and the unit jams up. To get around this I just quickly press the whole tray in at once to keep them together. All the belts are good and I think I lubed everything so I am not sure what is causing it to get stuck.
 
I have no idea. The tray issue sounds like a mechanical interlock issue. To be honest I have not seen either of those failure modes.
 
Awesome figured out the clicking issue. A wire I had accidentally broken when trying to get at the RF board a while back (before the cap solution) broke again. Seems it is the signal wire that connects to the leaf switch. Rewired it and did a better job soldering it together and the problem is fixed. Once I solve the tray issue I'll be golden.
 
Just FYI in case people refer to this thread in the future...

I noticed quite a bit of skipping near the end of some CDs (not all though) a few days after I fixed the unit. These tended to be longer CDs or CDs that used the whole platter. It was always the last track.

Anyway this necessitated a slight tweak (1mm in my case) of the laser pot to fix the issue. I would suggest running a test CD that runs to as close to the max time as possible and going to near the end of the last track. That should answer if you need to make more adjustments.

Of course if you have the right measurement equipment then you could fix it without using an audio check...I only have my ears and a screwdriver in this case.

Now I just need to solve this tray issue.
 
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Rich Andrews said:
I just posted my fix to the hints/kinks subforum regarding the distortion/noise that I was experiencing. All in all, it was fairly easy. I didn't have to remove the RF amp board to replace C213. Now it is solid and none of the controls are touchy and I didn't have to touch the laser output pot either. I just set the tracking gain and focus gain back to where it was to begin with and then adjusted the two pots on the RF amp board for max RF output. It actuially played with the two RF amp pots in the middle of their range which is what I would expect. All in all, it all just neatly fell into place.

How did I come up with C213 as the problem? I had talked to a McIntosh tech/engineer a few years ago and took some notes.

Drilling two 1/4" holes in the plastic side frame made access to the RF amp pots easy. Finding a suitable screwdriver was the hard part. I wound up making one but I am sure there is an Xcelite screwdriver out there that would work.

Richard - who is listening to Pink Martini's Xmas album and liking it.
Click to expand...
Thanks, Rich. Fourteen years later I encountered this problem and replaced C213 with a polyethylene capacitor. Good as new!
 
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