Technics SL-PG400A won't read discs specially on winter

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jrsilva00
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Technics SL-PG400A won't read discs specially on winter

Post by jrsilva00 » 13 Feb 2020 10:39

Hello.

I'm a proud owner of a Technics SL-PG400A CD player, that I bought new back in the early 90's.
It' s been playing CD's without any problem since then until it started to develop a strange Behaviour in the last 2 years.
Some CD's take a long time to be recognized and to start playing.
First this difficulty started on home recorded CD-R's and some originals too.
Now, 2 years past, it happens with any CDs, even on recent purchased CD's.
Some CD's are read, but it takes a long time to be recognized.
I mean, I can ear the disc spinning (and sometimes some clicks inside the tray), the display pulse a bit, with all the info displaying only zeros.
Some CD's are recognized after about a minute or a bit more, some take around 10 to 15 seconds.
But the more strange thing is that I've noticed that during the summer season the player is more capable of playing the CD's. Some CD's take only around 2 or 3 seconds to be recognized.
Having noticed this behavior it came to my mind why not try a hair dryer pointed to the open tray...
So I did that. When I point a hair dryer to the open tray of the CD player and give a warm blow for about a minute and then put a CD (even a home recorded CD-R, or very old CD's) it takes only one second to read!... It's blazing fast to recognize the CD and start playing.
I can then change the CD for another one and it plays without any hesitation.
But if I turn Off the unit and turn ON an hour or so later it does not recognize the CD's anymore, and I need to get the hair dryer again...

Last weekend I've opened the unit and cleaned the laser lens.
I've moved the laser head gently to see if there are any stiff movement or so, but it looks good to me.
I've spayed the electric contacts (with WD-40) of the jointing terminals between the CD tray and the main circuit board.
It did not made any difference. The player only recognizes the CD's after a bit of a warm blow from the hair dryer.
Looks like the player needs to be warmed up to be able to play the CD's.

Does anyone had this same problem?
Got any clue why is this happening?
Let me point that my house is not very humid. It have the normal amount of humidity and I even tried to put a humidity absorbent on my living room where the player is.

Than's for reading.

Vinylfreak86
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Re: Technics SL-PG400A won't read discs specially on winter

Post by Vinylfreak86 » 13 Feb 2020 13:25

Maybe some problem with microelectronics. Thing is nearly 30 years old and when it was made new, they didn`t had in mind it will still work in 2020. If price is not so high, general overhaul is a good idea. Otherwise buying a new CD player from companies like Yamaha, Denon, Onkyo, NAD...

jrsilva00
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Re: Technics SL-PG400A won't read discs specially on winter

Post by jrsilva00 » 13 Feb 2020 13:30

Vinylfreak86 wrote:
13 Feb 2020 13:25
Maybe some problem with microelectronics. Thing is nearly 30 years old and when it was made new, they didn`t had in mind it will still work in 2020. If price is not so high, general overhaul is a good idea. Otherwise buying a new CD player from companies like Yamaha, Denon, Onkyo, NAD...
A general overhaul may be a good idea. Problem is that I don't know or have any good service shop in my town.

Vinylfreak86
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Re: Technics SL-PG400A won't read discs specially on winter

Post by Vinylfreak86 » 14 Feb 2020 11:06

jrsilva00 wrote:
13 Feb 2020 13:30

A general overhaul may be a good idea. Problem is that I don't know or have any good service shop in my town.
I had similar problems with my former direct-drive turntable, which was very complex designed thing with a lot of electronics inside. I thought that it could be moist or oxidation of contacts, sent it few times to a serviceman, but after some time problems occured again. At the end I gave up, sold it and bought another more simple designed turntable from the same generation. With this one I have no problems. General overhaul of that turntable would cost me more than 200 eur, for my current turntable I have paid only 40 eur.

Pauw
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Re: Technics SL-PG400A won't read discs specially on winter

Post by Pauw » 14 Feb 2020 13:01

I think it sounds like the laser is on the way out.....they can be replaced .

jrsilva00
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Re: Technics SL-PG400A won't read discs specially on winter

Post by jrsilva00 » 14 Feb 2020 13:09

Pauw wrote:
14 Feb 2020 13:01
I think it sounds like the laser is on the way out.....they can be replaced .
Do you think so?
But when I pick up a hair dryer and warm up the tray of the player it plays the CD's from start to finish without any problem. :-k

Tinkaroo
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Re: Technics SL-PG400A won't read discs specially on winter

Post by Tinkaroo » 14 Feb 2020 13:27

Just a thought but perhaps the slides on the laser mechanism don't work as well when the temperature is cold perhaps since the lubricant is old? Maybe a cleaning and fresh lubricant might help.

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Re: Technics SL-PG400A won't read discs specially on winter

Post by Tonybro » 14 Feb 2020 13:34

This sounds like one or two things, possibly both. ;-)

If it's only happening in Winter then either the unit is getting condensation on the lens which will affect laser focusing which then clears as device warms up (hairdryer treatment you mention). Or (possibly and) the lubricant is old and if the device is cold the lubricant on the rails isn't up to temperature and sticking so the tray can't get to the right position for the laser to focus.

jrsilva00
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Re: Technics SL-PG400A won't read discs specially on winter

Post by jrsilva00 » 14 Feb 2020 15:29

Thank you Tinkaroo and Tonybro.

As for the moisture or condensation possibility, I doubt.
My house it's not very humid.

I'm starting to suspect that indeed could be the lubricant on the rails.
Because I now recall that some time ago when this issue started to happen, sometimes when the player was spinning the CD trying to read, I've heard some very loud crackles inside the tray.

I only opened the player top cover. I've no experience on disassembling the tray of a CD player.
Could someone point me were those rails are usually located?
Can I use WD-40 as lubricant, or something else?

lenjack
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Re: Technics SL-PG400A won't read discs specially on winter

Post by lenjack » 14 Feb 2020 16:30

WD40 is not a lubricant. What has happened here, is that the old lube has died out and hardened. When you warm it up, it "unhardens" and starts to work. Needs to be removed, and replaced with new, some sort of lithium grease, or a product such as Superlube, not sure where available where you live.

billrog787
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Re: Technics SL-PG400A won't read discs specially on winter

Post by billrog787 » 14 Feb 2020 22:46

If you do manage to locate the rails, this type of grease is good for lubrication. https://encosystems.net/product/tribol- ... 90-grease/

Bill.

jrsilva00
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Re: Technics SL-PG400A won't read discs specially on winter

Post by jrsilva00 » 17 Feb 2020 10:44

Thank's lenjack and billrog787 for your replies and tips.

I was about to ask if I could use vaseline or something like that.
I will look after that Superlube and Tribol lub.
As soon as I have a spare time I will remove the player top cover again and see If I'm able to get into the rails.

lenjack
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Re: Technics SL-PG400A won't read discs specially on winter

Post by lenjack » 17 Feb 2020 16:13

No tp vaseline.

jrsilva00
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Re: Technics SL-PG400A won't read discs specially on winter

Post by jrsilva00 » 17 Feb 2020 16:16

lenjack wrote:
17 Feb 2020 16:13
No tp vaseline.
Thank's for the advice.

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