exxos's Atari, Amiga & retro forum

Good news on the classic.

@Kai Robinson I believe he is working on a clasic ram board replacement

Tom

Tomswork wrote: 11 Jan 2022 16:56 Good news on the classic.

@Kai Robinson I believe he is working on a clasic ram board replacement

Tom

Indeed I'm rather pleased :)

Cool, I do have a Simm board that used to work, but has decided not to :(

@Kai Robinson are you building a replacement by any chance?

@rubber_jonnie

Whats next on the repair list ?

Tom

Tomswork wrote: 12 Jan 2022 02:32 @rubber_jonnie

Whats next on the repair list ?

Tom

Well, the good news is that the Mac powered up first thing this morning, which has been a problem in the past, so fingers crossed the replacement QP2 is the final fix. I did replace a LOT of caps, but I don't think that's a bad thing, and the ones I originally replaced when I first started looking at this back in my old house were actually all leaking anyway.

Picture is good now, but I think the deflection yoke needs a tweak as the image is ever so slightly rotated anti-clockwise, but that's no big deal.

Then it's just the RAM. It sometimes works, sometimes doesn't and it feels like it's a connection problem, which is annoying, but once that is done and the final tweaks are done to the display, it's good.

Meanwhile I'm waiting on parts for the Aquarius and need to replace some sockets on the 600XL, see if that resolves its problem.

Then I have a repair job on an STE from somebody else on the way. I don't usually do repairs, but offered on this occasion.

rubber_jonnie wrote: 12 Jan 2022 08:50 Picture is good now, but I think the deflection yoke needs a tweak as the image is ever so slightly rotated anti-clockwise, but that's no big deal.

Says you. That would drive me absolutely batty! :lol:

derkom wrote: 12 Jan 2022 10:04

rubber_jonnie wrote: 12 Jan 2022 08:50 Picture is good now, but I think the deflection yoke needs a tweak as the image is ever so slightly rotated anti-clockwise, but that's no big deal.

Says you. That would drive me absolutely batty! :lol:

I meant it was no big deal to adjust :)

As it happens I have adjusted it and it looks way better :)

Of course now the centring and image size is off slightly, but they can all be adjusted by the pots on the back, so quick and easy to do. Will probably do that at lunchtime today :)

rubber_jonnie wrote: 12 Jan 2022 10:10 I meant it was no big deal to adjust :)

As it happens I have adjusted it and it looks way better :)

Phew! :dizzy: :D

derkom wrote: 12 Jan 2022 10:12

rubber_jonnie wrote: 12 Jan 2022 10:10 I meant it was no big deal to adjust :)

As it happens I have adjusted it and it looks way better :)

Phew! :dizzy: :D

What is mad is that the picture shape is controlled by 8 magnets around the deflection yoke, that can all be rotated to tweak the image :dizzy:

One thing this whole adventure has taught me it that as long as you respect the CRT and follow some basic rules, then it can all be done safely.

I just need to get the RAM upgrade sorted really, and it's done :)

rubber_jonnie wrote: 12 Jan 2022 10:20 One thing this whole adventure has taught me it that as long as you respect the CRT and follow some basic rules, then it can all be done safely.

Yeah, I found the same when first working on a SC1435 and the after that a SM124. It is safe, as long as you follow the rules, and actually kind of fun to be working in the analog domain, where a lot of the technique ends up being "shove this around until it works". :lol:

derkom wrote: 12 Jan 2022 10:22
Yeah, I found the same when first working on a SC1435 and the after that a SM124. It is safe, as long as you follow the rules, and actually kind of fun to be working in the analog domain, where a lot of the technique ends up being "shove this around until it works". :lol:

Yeah, I found that as I replaced caps in the analog board video circuit, things changed on screen, so then I had to tweak the pots and deflection yoke, (And later the magnets) to get it back to normal.

It is a totally different way of working to what I'm used to and definitely much more of a vague way of working, as you described :lol:

What's quite nice is one of my uncles was a TV engineer back in the 70's and did all this sort of analog stuff, and I'd like to think he'd be proud of where I'm at if he were still around :)