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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Munchkin on January 28, 2015, 06:23:34 PM
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Hi.
Haven't been around for quite some time due to a difficult case of life. Decided to start playing around with my Amigas again though and started having some trouble.
Through the years I've had my A4kD on from time to time and haven't had any issues. Now, it stood unused for about 6 months and then when i started it up again I experienced some graphical problems.
It works just fine as long as I use the CV64/3D as output. It doesn't crash more often than it used to and everything seems to work as it always has. However, when I try to do anything through the onboard gfx I experience problems.
First time I noticed was when starting DeLuxeGalaga and all I got was a garbled output on my old 1084. I see colours but it's only rapidly rolling stripes and I can't really see what's on there.
To begin with I thought it might be the monitur that's gone bad but after putting in my scandoubler and connecting an old 17" monitor that's worked before I started seeing issues on that as well. Mainly that the system locks up after a few seconds, I never even get a picture. This could of course be bad contact on the board so I guess I need to clean it up properly to begin with.
Getting into the boot screen at startup i experience slight distortions and sudden flickers but it tends to get more stable after a little while. Though, after doing this I can, after bootup, get Galaga to fire up and show the game screen for a few seconds before it loses it again.
I've checked the battery, there's no leakage so it can't be that. I've been thinking about the PSU being the culprit, it is over 20yo after all. Besides that I can't really think of anything myself. Should I take it all apart, circuit after circuit and clean everything up properly before reseating again?
I might take a picture and post of how the distortions look.
Ideas?
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I think you should check capacitors, esp. audio ones. Also, check the PSU connector.
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Yup, problems that correct themselves after the machine "warms up" might indicate bad capacitors.
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Bunches of people do the re-capping service. Depending on where you live and shipping costs, I've been seeing some good things about this fellow (http://maccaps.com/MacCaps/Repair_Service.html). Looks like he now has an ad on ebay, too. ;)
http://www.ebay.com/itm/Amiga-A4000-Re-Cap-/181650361953?pt=LH_DefaultDomain_0&hash=item2a4b348e61
Alternatively you can send it to AmigaKit, or buy a kit of caps and do it yourself (think they run about $10), etc. IMHO get this done before you waste any more time troubleshooting. ;)
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Don't have an answer about graphics...
watch that battery! It's a ticking time bomb!
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Don't have an answer about graphics...
watch that battery! It's a ticking time bomb!
I'm aware of the battery. Had it replaced at one point but that didn't last very long either. Been meaning to remove it completely but haven't gotten round to it yet. Will do at once. Should really rebuild to have a clock battery instead but I've just been to lazy.
About the problem though. First thing I will do is take it all apart and clean it up properly, not just dust but also check for oxidation in the zorro slots and so. Perhaps try and replace the PSU if I can find a suitable one to replace it with.
If this doesn't work I'll try and replace caps to see if that does the trick. I wouldn't be surprised if this is part of the problem, it's 22 years old after all and have been doing a lot of work, for a few years it was on 24/7 when I ran an irc server and a bot on it.