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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 15th Nov 2021, 5:27 pm   #401
ajgriff
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Default Re: Commodore PET 2001 voltage regulators

That's odd Tim. I suppose I could be mistaken about the three prongs. Let's see if anyone else has a view.

Alan
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Old 15th Nov 2021, 5:33 pm   #402
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Default Re: Commodore PET 2001 voltage regulators

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That's odd Tim. I suppose I could be mistaken about the three prongs. Let's see if anyone else has a view.

Alan
Thanks, Alan. Looking at the area on the CRT where everything has to go, it really doesnít seem very deep; so not sure if the two longer prongs should sit inside (which they can), then the smaller clip rests on the metal rim on the outside? Iíve tried to get the smaller clip in first, but as soon as the longer prongs go in, then the smaller clip pops out.

Tim.
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Old 15th Nov 2021, 6:09 pm   #403
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Default Re: Commodore PET 2001 voltage regulators

I have to admit that, with the smaller bit being electrically connected to the two longer bits, it does seem that the smaller bit should go inside the tube as well. I could be wrong though.

Did you (Tim) remember what we said about how pinching the round centre part on the cap from the sides should make the two prongs retract inwards towards each other so they will fit through the hole they are supposed to grab onto from behind when they are released? If you do that, does that allow the prongs + extra bit to go deeper in?

I wonder if AJ or Colin might be able to look to see what theirs looks like in-situ, after discharging them first of course. Maybe Colin might remember having to negotiate the same problem. The main thing to note is whether there is a dark coating on the main body of the tube, and then to observe how close to the edge of the hole it approaches. Normally there is a fairly wide un-coated gap surrounding the hole.

If that's the case here as well then maybe that bent 'hook' is supposed to be the 'spring' which pulls the hooks on the ends of the prongs firmly up against the inside of the hole, in which case it may well be meant to rest on the outside of the hole.

Last edited by SiriusHardware; 15th Nov 2021 at 6:18 pm.
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Old 15th Nov 2021, 6:36 pm   #404
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Default Re: Commodore PET 2001 voltage regulators

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I wonder if AJ or Colin might be able to look to see what theirs looks like in-situ, after discharging them first of course.
Done. Only the two splayed prongs sit in the recess and the curved part rests against the outer surface. Life is full of surprises.

Alan
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Old 15th Nov 2021, 6:38 pm   #405
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Default Re: Commodore PET 2001 voltage regulators

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I wonder if AJ or Colin might be able to look to see what theirs looks like in-situ, after discharging them first of course.
Done. Only the two splayed prongs sit in the recess and the curved part rests against the outer surface. Life is full of surprises.

Alan
Thatís great - thanks for doing that, Alan. Right, I should now be able to get the two prongs in, then get ready for testing.

Thanks again,
Tim.
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Old 15th Nov 2021, 6:46 pm   #406
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Default Re: Commodore PET 2001 voltage regulators

Having caused the confusion in the first place Tim, I was obliged to take a look. Better still the PET is still working!

Alan
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Old 15th Nov 2021, 7:03 pm   #407
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Default Re: Commodore PET 2001 voltage regulators

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Having caused the confusion in the first place Tim, I was obliged to take a look. Better still the PET is still working!

Alan
Itís good news the PET is still working! Thanks once again. Iíll go and get the cap attached, then look at getting it connected to the PET. Fingers crossed!

Tim.
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Old 15th Nov 2021, 8:08 pm   #408
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Default Re: Commodore PET 2001 voltage regulators

Everything has been put back together and the monitor mounted onto the PET. I'm pleased to say it all still works!

That's a big relief, and not something I'd really like to do for quite a while again! A really fiddly job trying to get the CRT in (and out) of the case. Thanks again for all your help and support.

The gloss paint had hardened well, and it certainly looks better inside the monitor case now. Hopefully the rust is now a thing of the past. The PCB also had a light clean, as well as the anode cap. I've kept the cable airbourne as SiriusHardware mentioned (sorry, I had to google LOPT!), and it's not touching anything, nor the case.

Next job is to finish off the case, then we're onto the keyboard.

Tim.
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Old 15th Nov 2021, 9:02 pm   #409
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Default Re: Commodore PET 2001 voltage regulators

Oops, I did it again, yes, LOPT = Line OutPut Transformer, that chunky thing which the thick, high voltage cable comes out of.

It looks very smart now, well done.
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Old 16th Nov 2021, 1:09 pm   #410
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Default Re: Commodore PET 2001 voltage regulators

Good work. The PCB is nice and clean too.

Getting there.

Colin.


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Everything has been put back together and the monitor mounted onto the PET. I'm pleased to say it all still works!

That's a big relief, and not something I'd really like to do for quite a while again! A really fiddly job trying to get the CRT in (and out) of the case. Thanks again for all your help and support.

The gloss paint had hardened well, and it certainly looks better inside the monitor case now. Hopefully the rust is now a thing of the past. The PCB also had a light clean, as well as the anode cap. I've kept the cable airbourne as SiriusHardware mentioned (sorry, I had to google LOPT!), and it's not touching anything, nor the case.

Next job is to finish off the case, then we're onto the keyboard.

Tim.
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Old 16th Nov 2021, 5:40 pm   #411
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Default Re: Commodore PET 2001 voltage regulators

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Next job is to finish off the case, then we're onto the keyboard.
If the keyboard is still working well without any sticky or erratic keys I'd be tempted to just remove it, give it a good skake upside down and then simply clean the keys with a moist cloth without removing the caps. Don't see the point in disturbing things just for the sake of it.

Alan
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Old 17th Nov 2021, 5:08 pm   #412
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Default Re: Commodore PET 2001 voltage regulators

You have no sense of adventure.

Colin.

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Next job is to finish off the case, then we're onto the keyboard.
If the keyboard is still working well without any sticky or erratic keys I'd be tempted to just remove it, give it a good skake upside down and then simply clean the keys with a moist cloth without removing the caps. Don't see the point in disturbing things just for the sake of it.

Alan
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Old 17th Nov 2021, 5:30 pm   #413
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Default Re: Commodore PET 2001 voltage regulators

True and I can't type accurately either (skake!?).

Alan
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Old 17th Nov 2021, 9:24 pm   #414
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Default Re: Commodore PET 2001 voltage regulators

The case has now been cleaned, so they keyboard beckoned. It turned into a rather large job. On taking out the keyboard, I was hoping I might get away with what Alan suggested; however, the keyboard was absolutely filthy. So I ended up having to remove the keycaps in order to give it a good clean, then the keyboard itself. After a lot of cleaning, it was put back into the PET and all works as expected. So another job off the list!

Tim.
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Old 17th Nov 2021, 9:26 pm   #415
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Default Re: Commodore PET 2001 voltage regulators

All of the exterior cleaning has now been done; screen, casing, and keyboard. The rust has been addressed in the monitor case, and the very small specks on the case have had a drop of the rust neutraliser. The whole lot has then had a polish. I donít think Iíll do anything further as I think it looks okay now.

With that now done, itís time to address the inside of the case (mainly dust again in the bottom under the PCB), and the transformer.

It's getting there.

Tim.
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Old 17th Nov 2021, 10:13 pm   #416
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Default Re: Commodore PET 2001 voltage regulators

Stunning! Strange to think that this thread started with a question about voltage regulators.

Alan
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Old 17th Nov 2021, 10:34 pm   #417
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Default Re: Commodore PET 2001 voltage regulators

The two prongs fit in the crt cavity, the third bit stays in the final anode rubber cap, don't worry about it, it is only a monochrome crt, the voltages here are fairly low compared to colour tubes.
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Old 18th Nov 2021, 10:53 am   #418
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Default Re: Commodore PET 2001 voltage regulators

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Stunning! Strange to think that this thread started with a question about voltage regulators.

Alan
Thanks, Alan. Yes, all started with no 5V in the PET and the wrong assumption (on my part) that it could have been the voltage regulators! It's certainly come a long way, and I couldn't have done it without the help from all of you on the forum.

Thanks once again!

Tim.
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