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-   -   Technics SL-PG440A CD Player - Needs help! (https://www.vintage-radio.net/forum/showthread.php?t=79301)

Ricardo 28th Jan 2012 9:53 pm

Technics SL-PG440A CD Player - Needs help!
 
I have a Technics SL-PG440A CD Player as part of a separates Hi-Fi system, which has had little use over the years and has always worked perfectly until now.

After a period of several months idleness the unit was called upon to play a CD that had arrived as a Christmas present. Upon power-up a CD that had been left in the drive automatically started to play. After a few seconds this was stopped, ejected and the new CD inserted. This new CD was not recognised at all and since then the unit fails to recognise any disks!

I have taken the top cover off and these are my observations so far:

Opening and closing of the tray mechanism is fine. The laser assembly seems to move towards the centre of the disk for a few seconds initially then returns to its idle position. The CD does not spin at all.

Can someone tell me whether the disk should always spin when trying to read the disk information or will this only happen if the laser optics unit is working correctly?

Any clues as to how to progress with my fault finding of this unit would be appreciated.


Regards,

Richard

paulsherwin 28th Jan 2012 9:55 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
The disk should spin up so that the table of contents can be read.

Have you checked that the spindle motor is free to spin?

ben 29th Jan 2012 4:48 am

Re: Technics SL-PG440A CD Player - Needs help!
 
Clean the lens. Should always be the first step to narrow things down with CD players. They pick up dust no matter if left idle or in use.

tri-comp 29th Jan 2012 10:24 am

Re: Technics SL-PG440A CD Player - Needs help!
 
Ricardo

The first thing that happens when the tray is closed is that the laser turns-on and tries to focus on the CD.
If it is able to focus, the CD spins (given that the motor works!). No focus = no spin.
So Ben is right. Cleaning the lens is always the first and easy step.
The next step may not be so easy.
Replacing the defective laser-ass'y could be next if cleaning doesn't help.
Determining IF the laser-ass'y needs replacement is of course the problem.
Not easy to diagnose remotely :shrug:
I do have the service-manual for this player. PM me with your e-mail address for more info on that.

rgds,

/tri-comp

Ricardo 29th Jan 2012 11:32 am

Re: Technics SL-PG440A CD Player - Needs help!
 
Thanks for all the replies.

The spindle motor seems free to spin when turning it by hand. However I think it might still be a cause of the problems. When reading a disk now it sometimes tries to move, but doesn't spin properly. It has spun up at least once and has even read the table of contents, so the laser hasn't failed completely.

I have tried carefully cleaning the lens, but it hasn't fixed the problem.

tri-comp, as you say the difficulty now is determining whether it is the laser assembly that is faulty or a problem with the motor.

I have downloaded a copy of the service manual for the unit from the internet. I have been trying to follow the fault finding guide and without a CD in the tray I can see that the focus lens is making vertical movements. I am not sure how to proceed further. I have an oscilloscope available, but I don't have the playability test disk that is mentioned in the service manual.

Any advice as to how to proceed further would be welcome.


Regards,

Richard

Ricardo 29th Jan 2012 12:53 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
A progress update.

I now have a CD loaded and the player has read its table of contents. With the disc spinning I can select tracks and play them faultlessly.

The problem comes if I stop the disc. When the play button is pressed the spindle motor sometimes spins up OK on its own, but quite often it needs some help to start turning. Once it is running at full speed it is fine.

Does this enevitably mean a new spindle motor is needed or could there be another explanation? If these are still obtainable can it readily be replaced without too much difficulty?


Regards,

Richard

Michael Maurice 29th Jan 2012 1:25 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
The spindle motor together with the laser is part of what is known as the traverse deck. (item 126)

Individual parts are not available.

The part number is RAE0111Z

According to SEME its discontinued but you might have better luck through Panasonic.

Try giving Panasonic spares direct a call on 01344 860133

Send me a PM if you have difficulty.

ben 29th Jan 2012 4:37 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
A shot of contact spray through an opening in the motor may be worth a go. Also measure the supply voltage.

Ricardo 29th Jan 2012 5:45 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
Michael,

Thanks for the information about the part numbers, etc. Shame it isn't possible to replace the spindle motor on its own. The whole traverse deck including the laser sounds like it might be expensive to replace?


Ben,

I haven't dismantled the unit enough so far to see whether or not your suggestion of spraying contact cleaner into the motor is practical to do.


The latest situation however is that having played a CD from start to finish a few times the spindle motor is now behaving itself perfectly. Just how reliable it is going to be in future is another question!


Regards,

Richard

Michael Maurice 29th Jan 2012 7:22 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
You may well find that as the motor has been used, its slightly freed up the bearings. if you feel brave enough, see it you can get it out and see if its one of the common spindle motors.

One trick that an ex Mastercare engineer did , was to put drops of oil in it the run the motor off a 30V supply for 10-15 mins.

sp10mk11 29th Jan 2012 7:31 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
As Ben said i would take out the motor and spray a bit of switch cleaner in it, i then used to power them up on a 5/6 volt supply backwards for a 30 secs and this can help.
Is it a philips transport? (memories coming back to me that some used philips transports)

arghh im geting too old and doddery

Good luck

Michael Maurice 29th Jan 2012 7:36 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
Its not a Philips transport, your suggestion could work, I wouldn't spay switch cleaner though, sewing machine oil may be better.

sp10mk11 29th Jan 2012 7:56 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
The only problem with oil is might contaminate the brushes on the motor, whereas servisol switch cleaner wont infact it help clean any carbob deposits of them and also clean out the bushes on the motor it has a lubricant in it,
up to you though ;-)
Gary

Michael Maurice 29th Jan 2012 8:23 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
Point taken Gary

Ricardo 29th Jan 2012 8:46 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
Thanks everyone for the various comments and suggestions about lubricating the motor and cleaning the brushes.

Right now it is working well again. So unless or until the spindle motor starts to play up again I'm not going strip the unit down further to try these suggested solutions to prolong its life.


sp10mk11, My researches into this unit showed the transport unit to be type CDM4/19 and this type is used in quite a few Phillips machines, as well as various Marantz, Technics and other models.


Thanks again everyone for your help. I am hoping that with slightly more frequent use the spindle motor will keep working for a while yet, but if it does start to misbehave again I will try to revive it with some lubrication / cleaning and running outside of the machine.


Regards,

Richard

Michael Maurice 29th Jan 2012 8:53 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
If you've got the cover removed, can you post a picture please? I'm surprised that Technics used a Philips mech.

sp10mk11 29th Jan 2012 8:54 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
arhh so it is a Philips transport......... they in my experience where pretty reliable, the worst offenders for taking out spindle motors were the old Pioneer 6 disc multi players, two years and the motor was gone, outwardly it was very similar to the one philips used at the time.

Yes keep it running for a while and use it regulary and it should be ok

Good luck
Gary

sp10mk11 29th Jan 2012 9:00 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
Michael
I was surprised to find philips transports in the lower range technics machines of the time, maybe it was cheaper to use them, the older Technics linear tracking mech was probably to expensive for this range of Cd's
I remember looking inside a Bose wave radio thingy and it had the cheapest Sanyo transport in it ;-( never mind ;-)

Ricardo 29th Jan 2012 9:24 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
1 Attachment(s)
Michael,

Here is a photo, as requested.

Attachment 61941


Regards,

Richard

Michael Maurice 29th Jan 2012 9:52 pm

Re: Technics SL-PG440A CD Player - Needs help!
 
I'm quite surprised Richard that is indeed a Philips Mech, and as fare as I know its obsolete.


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