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General Category => Technical Support => Hardware related => Topic started by: thomas on 18:35, 11 June 21

Title: An Ebay bargain ...
Post by: thomas on 18:35, 11 June 21
Nice surprise when you buy a 464 from fleebay advertised as "yeah, working except for the tape drive, might need a new belt" and you switch it on and get a black screen ... and have to botch 4 wires from the RGB port ... but this did it! :-) Machine sprang to live. Yeah!

I know, the botch job is miserable, but the joints were really bad and I just wanted to see if it works. Will try to make it better.

Minor issues left:
- one of the case screw holes broke off (but it's there, have to glue it back)- pause button does not snap in (a white wedge like thingy fell out of the case)- dirt, blue buttons discolored (but I knew that)
- would not accept a Dandanator

Sound chip and internal speaker work. :-)
- thomas


Title: Re: An Ebay bargain ...
Post by: Gryzor on 21:50, 11 June 21
Every CPC is worth saving🙂
Title: Re: An Ebay bargain ...
Post by: thomas on 10:11, 12 June 21
I will do what I can. But I already consider it "saved", more or less! :-)  Now, lets make it beautiful again.

- thomas


Title: Re: An Ebay bargain ...
Post by: Bryce on 11:36, 12 June 21
You've by-passed the RGB capacitors. Were they damaged or are the PCB tracks damaged? You should try to keep the capacitors in the circuit. It will give you a better picture.

Bryce.
Title: Re: An Ebay bargain ...
Post by: thomas on 13:04, 12 June 21
Bryce,

thank you for your message; your eyes are much better trained than mine, but the three botches go to C133-C135, which are (imho) directy connected to the resistors R126, R128, R120. (?)  The resistors are good, only the pads on the RGB out are bad. So it would not make a difference, I thought?

Picture is crystal clear (which always makes me smile when I switch from the C64 to an Amstrad ...:-), but the colors are still a bit off (what is supposed to be yellow is green at the moment ...).

But this was just a really quick fix to prove my assumptions, still have to improve! :-)

- thomas
Title: Re: An Ebay bargain ...
Post by: thomas on 21:36, 12 June 21
Making progress with the case.
However, the pause button is not fixed yet: I have the wedge and my Roomba picked up this tiny plug, which I later noticed can be seen being stuck in one of the case slits in the picture of my first post (I lost it without noticing ...)!
 
:-)

But there is supposed to be a spring between the peg and the wedge or beneath the wedge? (one YTer I don't remember right now has made a video about that mechanism; I'll have to check!)

- thomas

Title: Re: An Ebay bargain ...
Post by: gerald on 23:07, 12 June 21
But there is supposed to be a spring between the peg and the wedge or beneath the wedge?
Yes, there is a tiny spring !
Title: Re: An Ebay bargain ...
Post by: thomas on 10:03, 13 June 21
Gerald, thank you! :-) I think I found the spring! :-) It dropped on the ground when I first opened the case. Spring's length is 8 mm.
Title: Re: An Ebay bargain ...
Post by: thomas on 10:21, 13 June 21
yes, the spring fits! :-)
Title: Re: An Ebay bargain ...
Post by: Bryce on 12:18, 13 June 21
Bryce.

Title: Re: An Ebay bargain ...
Post by: gerald on 21:07, 13 June 21
Gerald, thank you! :-) I think I found the spring! :-) It dropped on the ground when I first opened the case. Spring's length is 8 mm.
Good new. That spring always want to make secession  :D
Title: Re: An Ebay bargain ...
Post by: thomas on 16:57, 14 June 21
I made a picture of the pause button mechanism parts for reference.

Title: Re: An Ebay bargain ...
Post by: Bryce on 17:10, 14 June 21
Another Slide Rule (Rechenschieber) fan among us?

Bryce.
Title: Re: An Ebay bargain ...
Post by: thomas on 17:35, 14 June 21
The Rechenschieber is an heirloom, probably older than the 464!  ;D
Title: Re: An Ebay bargain ...
Post by: thomas on 17:38, 14 June 21
Noel gave attention to the pause button: https://www.youtube.com/watch?v=aC0WpCXMPno (https://www.youtube.com/watch?v=aC0WpCXMPno)

Title: Re: An Ebay bargain ...
Post by: Bryce on 20:11, 14 June 21
The Rechenschieber is an heirloom, probably older than the 464!  ;D

My "pocket calculator" is an Aristo 868 Studio from 1952. Bugs the shit out of my colleagues when they ask for a calculator and I hand this to them :)

Bryce.

Title: Re: An Ebay bargain ...
Post by: ComSoft6128 on 20:29, 14 June 21
Many of my customers were retired and the CPC was their first computer. One of them phoned looking for help with MD+ and we started chatting - he told me that "back in his day" he was part of the design team on the Concorde and much of it was designed using slide rules and tables though they did have occasional access to a computer with a massive 4K (6K?) of memory!
The 128K of the 6128 was a minor wonder to him.
Title: Re: An Ebay bargain ...
Post by: Bryce on 21:10, 14 June 21
Really showing my age now, but at my first job in engineering I didn't have a computer on my desk. They were only for the CAD guys. Computers existed, this was the early 90's, just that engineers had no reason to have a computer as there was no software that would have assisted us and internet and e-mail weren't really a thing yet.


Bryce. 
Title: Re: An Ebay bargain ...
Post by: thomas on 22:47, 14 June 21
Bryce,
I grew up in the spoiled 80ies and we had Casios; if I had to CALCULATE anything with the rule, I would be totally lost ... but this stirred up my couriosity and I took a closer look: mine is from "Nestler" and has "Darmstadt" printed on it. My first thought: "Oh, this was made in Darmstadt, which is nice, since I live closely." But no, it is the SYSTEM Darmstadt, developed in the 30ies at my Alma Mater! :-) I know nothing, but humbly willing to dive deeper into that topic. This will keep me busy for a while (and postpones the CPC restoration, which in turn postpones the restoration of my A2000 ...).
- thomas
Title: Re: An Ebay bargain ...
Post by: Bryce on 09:48, 15 June 21
I grew up in the not so spoiled 70's. We had calculators too, but I found slide rules cooler. Aristo were made in Germany (Hamburg), Nestler were made in Schwarzwald as far as I know.

Bryce.
Title: Re: An Ebay bargain ...
Post by: thomas on 19:56, 15 June 21
Ok after reading a few hours I learned to multiply!  ;D
Title: Re: An Ebay bargain ...
Post by: thomas on 10:35, 16 June 21
Some more progress with the case: I tried to restore the small blue enter key and put it in 12% H2O2 and left it under the sun for 4 days. It's not perfect, some grey mist is still visible, but the difference to the big enter key is obvious. Doubt it would fully restore if I brighten it for some more time ...

One of the pegs holding the cassette player broke off. I either leave it as is, print a replacement, or I could glue in a screw anchor. Haven't decided yet.

- thomas