Restoration & Repair

Enter Your Electronics & Design Project for a chance to win an $200 Shopping cart of product!

Submit an EntrySubmit an Entry  Back to homepage
Project14 Home
Monthly Themes
Monthly Theme Poll

 

For Project 14's Restoration and Repair month, I'm going to service a Philips GA-212 Electronic turntable that needs some TLC.

I have a perfectly working one too. When everyone switched to CDs, they moved their TTs to the attic. It seems that people got tired of keeping them and gave them to thrift shops around the 2010s. I purchased a significant amount, with the only rules that they had to look repairable and that I'd not to spend more than 25€ per table.

I then sell the fixed ones for a perverse amount online. With the proceedings, I buy records. The ones I can't fix, I post as pick'm'up for nothing on that same auction site.

 

What's Wrong with This One?

 

Almost nothing. It's in good condition and I'm sure it can be brought back to specs. Except for the power button.

 

for this blog, I'm often using other people's photos, even though I have the TT here on the bench.

For two reasons: to show that this one is loved by many, and to show that the issues are common. They have known failure modes.

The TT in the video is my own.

 

Power Switch

 

That's not an electronic defect but a chemical one. Philips used a type of plastic in the power switches that deteriorates.

Nothing you can do about that. They all have it. It's not even worth looking for a defect TT with a working switch, because it'll break as soon as it's used.

The plastic has gone brittle - loosing all its structural coherence.

My solution is to mount it in a way that you don't see it's broken, and include a switch in the power cable (from a dead IKEA lamp).

A completer solution would be to look for a clunky power switch where I can mount the original button knob on, or "something else". I will not include that in this exercise.

 

Speed Correction

 

The first fixable thing is that both speed correction dials don't work.

image source: a UK Audio Mart auction

 

This issue can have different causes. It can be electronic - either the circuit or the potentiometer defect.

More likely, it's a mechanical issue caused by not properly assembling the TT after opening it.

 

Switch Off at the End of the Record

 

This is also a common issue. There are several causes again.

The mechanism was advanced for its time (many of the concepts in this turntable were novel but turned out to be causes of issues in the long run).

 

In the HiFi days, auto-switch-off was seen as a bad thing by some.

Because the mechanics to detect it could slow down the TT near the end of the record or cause mechanical noise, even before the mechanism engaged.

I think this is ~€@#{, but anyways .

Philips solved it by putting a circuit in place that used a light bulb, LDR and a light filter inside the turntable.

I'll explain it in a future blog. It's very novel, very ingenious. But it doesn't pass the test of time.

The TTs that used a mechanical system typically survive for ever and work again after a clean-up. A handyman can fix those.

The Philips design needs electronics skills to fix.

 

That's it. There are, as far as I know, no other issues at this time.

It had other issues: the belt was melted and the speed selection capacitive touch buttons failed.

That's also to be expected with this TT. But I fixed those in the past, so won't be covered in this blog series.

 

 

Why Follow this Blog Series?

 

All repairs are on the electronics circuits. And everything is discrete electronics.

Electronics Basics at work ....

 

Hang On.