Technics SL-PS50 no power after front end and cd tray was serviced

[Synchro-bias]

I got a cheap $20 Technics SL-PS50, seller said it reads discs but doesnt play. It will not read 90s and beyond cds but will play 80s cds i have, and some cdrs.

I decide to take the front off and clean it and check the cd belt - since then dead no power. I will tomorrow check the power into mainboard, and possible front end issue? it has those connects like the later Technics amps such as the G50, which caused some issues.

I read on another forum someone played around with the adjustments and the player was like new again playing dics. I am thinking i could do the same possibly, though i have only a multimeter, no scope etc. or maybe is best to leave it and play the discs on my other cd players it doesnt play

 

[TECH---NICS]

check carefully connectors , if he powered up before intervention and doesnt after , u have a bad connection somewhere , 100% .

 

[SVI2004A]

Mhmm definitely check for alignment and fit.... possible dry joints on them...

 

[Synchro-bias]

Thanks Baily and Technics
Also, was a bit glumsy and dropped the screw driver while screwing back in the main board, not sure the screw driver damaged anything will check all over and yes alignment, i read someone fiddled on another audio site and got it working. What the poster did below.

They are 6 small yellow potentiometers on the left side of the drive, when you are looking from the front.

I marked the position of each one, than tried to move one by one and moving the third one (counting from front) caused, that now the inserted cd is properly read and playing normal cds is no more problem , but it is not possible to play cdr copies of cds.

So, it seems that the first potentiometer regulate laser power. Setting it little higher solved the problem and now all kinds of cds (original and copies) are played.

Cdrs are reflecting less light than original cds

 

[elnaldo]

If you plan to move any trimpots, I suggest you to take resistance measurements at both sides of the trimpots. "Marking" a trimpot is not accurate at all, I don't understand why people suggest this on the Internet.

A resistance measurement of each half of the trimpot will allow you to set it back to the original position if something goes wrong.

 

[Synchro-bias]

Thanks Elnaldo, The digital meter can measure resistance

Currently still dead no power to unit? any way to measure the power maybe to see if unit is getting power. Continuity on the pins, found 1 dry joint on a cap fixed still no power at front end

maybe the connectors need to be in more? going by pic

 

[markn2wae]

Those connectors are a bit "fussy" in that they CAN be intermittent if not pushed ALL the way in.

Also, you MAY have cracked solder joints on the bottom PCB and/or the front PCB where they connect.

A POSSIBLE fault may have been the screw issue you had (shorting out something, was it a loose screw?)

Mark T.

 

[Synchro-bias]

Hi Mark
Thanks for the reply and help
The screwdriver feel on the pcb while i was screwing the pcb back, it was powered off.

I noticed the laser move a little, took out all display cleaned connectors and touched up solder on any suspect parts, no power to front end, maybe they are not pushed right in as i can see a bit of a gap,to top that off connectors inside also, i made sure they were in and used contact cleaner on the pins.

It would be nice to just bypass them

 

[SVI2004A]

Solder looks thin on CN602

 

[Synchro-bias]

Thanks Baily, will check that, under light. I might get her firing tomorrow.

 

[Synchro-bias]

Bypassed the connectors and used wiring , still no power, at front end, i suspect the wire on one of these is not making contact with the solder pad. CN506-5 are also connectors to the front end, but they seem to click in well, so mistake must be with wiring