Hi there, hoping to get some help with a possible purchase.
Been offered a 464 (spares or repair) with an MP-1. Spares or repair as faulty as the screen isn't displaying correctly (see picture) and after checking the tape deck only rewinds and won't go forward.
I'm curious as to if it's worth getting to fix up; I'm after a project of sorts and can't get a 6128 yet so this 464 might do as a stop gap!
Any thoughts or opinions greatly appreciated.
Dabooka
Well, if you have it already there, why not repairing it? Nothing to lose and a good chance to learn new things and practice :)
464 is a simple machine to repair, if you cannot do that someone near you can do it for you.
If it's not possible then you can summon the ultimate Bryce killer card... (sudo Bryce)
And if everything fails then sell me the tape deck ;D
It's a weird looking picture not seen it before, maybe it's just the modulator thats faulty???
Looking at the picture the colours haven't been changed, so the gate-array hasn't been setup and it's in the default settings.
The CRTC seems to have been setup, because the image is a good size. I think I can see some text there too?
Could be a bad ROM.
Well I've took the plunge, I figured what the hell it'll be a learning curve if nothing else!
Hoping to pick it up later in the week and then we'll see what we have. If nothing else it can sit next to my GX4000 while I figure out my next move ;D
HUzzah! I've collected it and got it home.
Good news - MP1 works. Well it powers up :D
Bad news - once I turned it on it crackled; I appear to have a slightly loose power socket (not the plug on the MP1). So off it's been since. It also appears to have a rather slack / less than positive power switch which I need to look at in detail.
So it will remain untested and unplayed with for the next few days or so >:( while I get some time and space it strip it down, and look for dry joints and what not. I had hoped I could spend my energy figuring out the display problem....
Bah!
I'd see it as a great project and see if you can diagnose and fix it yourself. When I started doing this a few years ago, I cannot tell you the feeling of achievement I had from fixing my first C64 (sorry dirty word on here). Since then I've fixed loads of retro machines including a CPC 6128 (thanks to Bryce for his amazing help with that one). The more you do the better you understand the machines and early electronics is not only fascinating but a solid foundation for all the amazing stuff we have today :).
Thanks for the replies chaps.
I did want a project after all, so in that regards I'm well sorted I suppose ;D . I'm looking forward to getting in there and trying to clear it up.
Does anyone know what size power inlet I need or about replacement switches? Just so I can get them ordered in ready (Links for CPC or RS appreciated if possible!). Already got my new iron, solder and flux pen winging its way over to me.
Quote from: endangermice on 23:57, 15 March 17
I'd see it as a great project and see if you can diagnose and fix it yourself. When I started doing this a few years ago, I cannot tell you the feeling of achievement I had from fixing my first C64 (sorry dirty word on here).
Does anyone have a recommended set of resources for learning to repair these kind of machines? like we do for learning z80 programming? Is there a 'fix retro computers for dummies' type book!?!
I was able to recap my Game gear, but I wouldn't know where to start or what to do if I had to fault find a broken machine - but it's something I'd be interested in trying to learn - these old systems aren't going to get more reliable with age!
Well, we have the service manuals in the Wiki. These are really useful. Then, there are many things covered in a lot of threads in the forum. For example, in some cases RAM ICs that go bad tend to get really hot. You can also try to start diagnosing your unit according to what you see in the screen. For instance, if you see a stable screen with a border you can suspect, again, that is going to be the RAM. However, a CPC that tends to type random characters by itself is likely to have an AY problem. A machine that works well but fails under heavy load is probably suffering from a bad cap. Bryce saw recently this when installing the 5VCPC in a unit, but it is true, in general, for many electronic devices that work and are not stable. If you Google your issue you will probably find an answer in the forum, although I think that not all the fixes have been compiled in a single document :) .
The most difficult systems to repair are those of the Plus range. If the ASIC fails you will probably end with a proper brick, since sourcing a new one is really difficult if not impossible and replacing IC, even if you had one, not an easy task.
Quote from: keith56 on 00:51, 17 March 17
Does anyone have a recommended set of resources for learning to repair these kind of machines?
Yes, you're a member of it, it's called The CPCWiki Forum :)
There have been a few books published, but they are all specific to particular machines. The problem is, that once you've passed steps one and two (1 - Check that all voltages are present and correct and that the current being pulled isn't too high. 2 - Check that the clock signal is present) it then becomes very device specific, which means that any book would need to be thousands of pages long.
My recommendation would be first to learn and understand the basic electronics principals (at least the digital principals) and after that you learn from experience.
@Dabooka (http://www.cpcwiki.eu/forum/index.php?action=profile;u=433): Both the power inlet and the power switch are both very robust components and should only need to be cleaned, there should rarely be a reason to replace them.
Bryce.
@keith56 (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1886)
There is a topic on the forum of what I went through to repair a 464 and a6128 this might help with comments from Bryce
http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/repairs-to-a-cpc6128/
Good luck and have fun
Ray
Thanks for the comments Bryce and Audronic.
Hopefully I'll have some time over Easter to get it apart and cleaned up, a few supplies needed (not to mention time) and then I'll try and get cracking.
In the meantime lots of reading up to do, in part to fix and in part to decide what I actually want to do with it all!
Dabooka