Help with Carver DTL50, Vintage CDPlayer

I have a bit of a problem when you get to the bit about the spindle spinning under the disc, and sometimes catching, and sometimes not. The disc should be firmly clamped to the turntable at all times, whether the spindle motor is spinning or not. With the disc loaded, the turntable should never be free to rotate independantly of the disc.

With the machine halted, confirm that the disc is flat on the turntable, and fixed there by the disc clamp. If it's not, then there's your problem, and it should be an easy mechanical problem to spot and fix. It's not uncommon on virtually any CD player, for the turntable to move slightly down the spindle motor shaft. This will then often prevent the disc clamp from firmly clamping the disc to the turntable. The turntable height is fairly critical ( to within 0.5 mm MAX ), so don't be tempted to move the turntable unless you're sure that it has moved. If you get to that point, come back again, and I'll see if I can guide you as to how to get it right

Geoff

my old Hitachi had a magnet that clamped the disc in place, the magnet came loose and got stuck right on the spindle instead of in the clamp where it belonged.

Mark

Hi Okay, I inserted the disc and it loads properly. Meaning the carriage takes the disc inside the machine and clamps it to the turntable. At this point, I am able to rotate the disc with my finger, in either direction. Meaning I can spin the disc freely, but does not have play up and down. I press play and the disc spins, there is a noise like loose stones rolling around inside the deck, the disc slows, slips a great a deal, then it comes to a halt. I advance the track to 2, and the disc spins much faster, then the same rolling stones noise, the disc stops playing and then slowly comes to a halt, like what you would expect if you had pressed the stop button.

I hope this is clear, I am a newbie, you know.

Thanks Steve

-- Stephen A Vicinanza Vicinanza Associates

121 Hickory Ave Staten Island NY 10305 1 718 981 2303

At the very least a proper lens cleaning is in order. Other maintenance as well, including cleaning any debris from around the spindle motor shaft and applying a bit of light oil there (clean away any excess). Other moving parts, slider surfaces etc should be cleaned and re-lubed as necessary. Routine maintenance such as this has fixed many a cd player, and is worth at least trying before looking for any more exotic problems.

Mark Z.

Hi Again,

Thanks for the good advice.

What is anyone's reccomendation for the type of lubricants I should use on the mechanical parts. For cleaning the lens I am going to use just alcohol.

Thanks Steve

-- Stephen A Vicinanza Vicinanza Associates

121 Hickory Ave Staten Island NY 10305 1 718 981 2303

A very light oil for the spindle motor, perhaps sewing machine oil, or I like a commercial product called Tri-Flow. I also use it on the metal rails on which the laser rides. It works much like WD-40 is supposed to work, except it seems to last, whereas we all know WD doesn't. It's silicon-based. A fine litium grease is good for plastic gears.

Mark Z.

Hi,

I cleaned and lubed the whole machine, but no joy, still having problems.

Here's whats happening.

When I first got it all together and put a disc in, the disk spun much faster then before and the machine picked-up the tracks really well. But alas, I had no output. The only sound I got was a bit of a crackling noise. There was still a kind of scrapping sound that sounded like some spinning part was rubbing against something else, when the disc is spinning, and after a few attempts at track changes, and then letting the machine sit for a while, I get the same problem as in the beginning. The disc doesn't spin fast enough, there's a grinding noise and then the disc stops, and slips on the spindle. (when this happens the display shows Disc, and never changes to a track number. Also on this machine it shows a 1.00 or a 2.00 for track number, then changes to a single digit when a track is actually playing) I did notice when I had things apart that there was a belt system on the left side near the back of the deck, and the belt is really loose. (the door open and close belt and gears system is on the right of the deck, near the front)

I am going to clean the lens again, which is part of the problem, I am certain. But any thoughts on the grinding noise would be a big help, and anything on why the spindle would not spin the disc or slipp would be a great help too.

I really appreciate you guys bearing with here.

Steve

-- Stephen A Vicinanza Vicinanza Associates

121 Hickory Ave Staten Island NY 10305 1 718 981 2303

I really think you need to replace any loose belt(s). The reason is that if the tray loading isn't 100% engaged, then the disc may not be clamping properly, and this could be your problem. Also need to confirm that the disc is not physically scraping the tray or other nearby part. Sometimes the suspension springs have sagged a bit and allow the disc to scrape. They can be stretched carefully to fix this.

Some Carver players used Sanyo / Fisher mechanisms and pickups. These aren't my best thing. What would be a bad pickup on any other player, for example, replacing a Fisher pickup never seems to fix my problems. I'm near 100% on other brands, but Sanyo / Fisher pickups make me look like an amateur.

Mark Z.

Stephen, are u sure u arent mistaking the noise produced by the optics for a mechanical grinding sound? If somethings impeding your spindle motor from attaining adequate rpm the cd would spin and then give up and stop.A simple test to gauge the problem....try playing track 7, if u can play later tracks then it could be a spindle servo problem(likely mechanical. Can u hook up an oscilloscope to rf out and observe the waveform and amplitude? If amplitude is low you might be able to tweak it by turning the preset at the back of the block a bit. The loose belt could be a sled motor belt, see if assisting traverse motion with a prod enables u to lock onto a track for a few seconds. Jango.

Hi Jango,

That was a very comprehensive answer. The grinding noises seems to be coming from the spindle and the top of the clamp, which rotates freely inside its housing. I am guessing most CD Players are like this. When the rpms are low, its very loud, when the disc catches and spins right, and the rpms are high, its lower in volume. It's a sound like a loose plastic disk spinning against something.

When you say transverse motion, do you mean giving the wheel a gentle nudge while it is spinning, to tense up the belt? The would be hard, since the belt and wheels are below the sled, when the disc is inside playing. The belt I am refering to is very loose, much looser then the door mechanism belt.

Oscilliscope is a whole different animal. I was trying to get away with not having to use one, if at all possible. Mainly cause I don't have one. And I'm not sure how much they cost, even a used one. If I was going to be repairing electronics all the time, it would certainly be a good investment, but its just the one deck. Might I adjust the preset at the back of the block, just tweak it a bit and see if that helps. When you say the block, which area do you mean, the laser housing, the spindle housing, an electronic part, the deck itself? Newbie here. I will also check my CD repair guide I downloaded from the internet. Got have some info, right? Can't be a total lamer. Ha ha!!

Steve

--
Stephen A Vicinanza
Vicinanza Associates
121 Hickory Ave
Staten Island NY 10305
1 718 981 2303
1 917 681 8788
vassociates@si.rr.com
"jango2"  wrote in message 
news:1120133401.467101.267040@g47g2000cwa.googlegroups.com...
> Stephen,
> are u sure u arent mistaking the noise produced by the optics for a
> mechanical grinding sound?
> If somethings impeding your spindle motor from attaining adequate rpm
> the cd would spin and then give up and stop.A simple test to gauge the
> problem....try playing track 7, if u can play later tracks then it
> could be a spindle servo problem(likely mechanical. Can u hook up an
> oscilloscope to rf out and observe the waveform and amplitude? If
> amplitude is low you might be able to tweak it by turning the preset at
> the back of the block a bit.
> The loose belt could be a sled motor belt, see if assisting traverse
> motion with a prod enables u to lock onto a track for a few seconds.
> Jango.
>

"I had no output. The only sound I got was a bit of a crackling noise. There was still a kind of scrapping sound that sounded like some spinning part was rubbing against something else, when the disc is spinning, and " Sounds like a mechanical problem, maybe the tray open close belt is loose and therefore the disc isnt being clamped in properly. Hence something is impeding it from achieving adequate rpm. Hence the crackling sound in speaker outputs. Try pulling the clamper assembly all the way up ("clamped in" ) by assisting it with your fingers, i usually do that by grabbing onto the sled rail and tugging upwards.Maybe the loose belt doesnt pull the disc all the way up. You ought to replace the loose belt . Did you try a later track like 7 or

8? ( where the required rpm is lower, hence u might get better audio output). Open up the clamper and see if anythings loose in there. Forget about what i said about assisting traverse motion, this sounds like more to do with the spindle.