Old A500+ issue..

[mastersetter]

Hi all, first post here. Long story short, old amiga user, back messing with my old machines. Escom a1200, works fine, old a500+ doesn't. When switched on, I get different colour screens. Initially I was getting red consistently, I read to try a different kickstart rom chip. Did that no change. Put the old back in and reseated a few other chips apart from agnus. I'm mostly getting a black screen now, although light blue and pink? aswell. The power led is flashing.
The battery did a little leak and there is signs of some damage but I didn't think it was too bad compared to some. Here are a few pics.










Board seems in good condition?
If I leave it running for a while, denise, agnus, the cpu are warm to touch, gary and the cia brothers are cold.
Anyone any ideas? I would like to get this old girl working again..

Thanks for any advice

*ps* sorry for the large photos.

[mastersetter]

Thanks all. I have a new gary chip in the post, will try that and see how it goes

[mastersetter]

Thanks, see that's the thing i'm confused about, im getting different colours on the boot than are in that list, it shows pink quite a lot ?! As for traces, maybe they are broken, the copper is discoloured due to the leak, hard to see really?

[mastersetter]

Thanks guys, I will try the chip and if nothing works then I will forget it, not worth the hassle and certainly not worth the money

[mastersetter]

Update, the gary chip had no effect. Thought about stashing this thing but I think I will have a go at a repair myself. Borrowed a multimeter, and using the pcb explorer (incredible) I have done some minor checking on traces around the leaked area. All of the ones that look bad are in fact fine, I get continuity through all of them, I could only find 2 that didn't work for me. One goes under one of the chips (74LS244N) and the other goes from a hole underneath a component and down to one of the pins on the expansion slot. Any idea why there is no solder in this hole? There are a few dotted around the board that I can see. I have treated and cleaned the area. Just waiting on my wire traces to appear in the post, and I will try and patch these two. Also the ground trace is fine.



You can see the clear hole underneath the lower leg of the upper yellow component here..

[mastersetter]

Thankyou Scuzzb, that is a help, im sure it's prob a through hole that was missed when it went through the wave, as many are filled. I may fill it when I put in the patch wire. Another question, are the chips replaceable? I can find them online, 74LS244N, so can I just swap one out for a new one?
 
 Glad you managed to get the battery off, hope the board is ok

[mastersetter]

I am not sure whether you can desolder the fixed chips and replace in truth. I am sure someone else here could advise on that. I wouldn't have thought it was a problem though for me I would be swapping out the motherboard because you are hoping to fix a problem that may in truth just expose another. I have spent way too much time trying to get busted kit working just to find its a hopeless case. Saying that I tend not to give up and do come back to problems over and over.

Keep a search open on Ebay and watch for old 500s [ busted and broken ] to appear and snaffle what you can for as cheap as you can. Having spares is always very useful.

Your photography and cleaning processes are excellent. I trust you are going to try an make a log of your efforts and create a little web page for it. That way others can learn from your experience.

Matters not in the end whether you are successful or not in truth as long as you enjoy yourself. Getting the Amiga working again would be a real bonus. So I hope you are successful. Don't give up.. but maybe do some sideways thinking [ get some spares ]

Yes indeed, your right in many ways. Fixing one thing may reveal anoother issue. It seems to bother me that it doesn't work, i'm enjoying researching and tinkering with it but like you say in the end it may not be enough, but im learning so it's worth it. I have just finished restoring my a1200 (cleaning, retrobrite etc) and it turned out well. I have been watching some old amigas on ebay, but they are not really cheap, even in non working condition, around £40 and up
 
 But will see where we end up :laugh1: I will try and update this thread with progress.

[mastersetter]

Just a quick update, 2 trace links soldered, switched on & held my breath..



Incredible! What a surprise to see that lovely boot screen after so many years. This a500 was bought by my father back in 92, and he loved this machine. Just wish he were around to see this working again, I'm sure he would be very happy.. just as I am. I will press on now, and continue to restore this old girl back to her former glory, just hope she works when it's all back together!!

Thanks for all the help and advice here, much appreciated
I will continue to post some progress when I have the time.

Michael T

[mastersetter]

Thanks all, I have no expertise in electronics at all, just got lucky with it maybe. I would have been lost if I didn't have the pcb explorer to tell me where the traces link, I printed a load of them out and checked one by one. 2 faulty is all I could find. I have used the vinegar, and cleaned with ipa, hope that's enough. Another update, the floppy drive isn't working. Tried a good clean of various parts and little oil on the motor screw, still no luck. Disk in, 3 ticks, then back to boot screen. May have to get an old one on ebay but not sure I want to spend 20£ on an old floppy drive! Madness!!

[mastersetter]

Hi, just a quick note. Case & keyboard restored as best as I could manage. All back together, still with a faulty floppy (for now)

Very happy with how it turned out.







Will make up a nice new box for it and store it safely.

[mastersetter]

Orange, tried that buddy, same thing, 3 ticks then back to loading screen

[mastersetter]

I only have an escom a1200, which isn't much use in this regard I don't think?

[mastersetter]

The 1200 has an old seagate 2.5 210 mb hd, the a500+ is stock apart from the marpet 1mb expansion card. The joystick is a cruiser, it's as old as the Amiga. It took many a beating on all my games over the years, but still works fine!

[mastersetter]

I'd connect the a500+ floppy drive to escom A1200. just take care of the READY signal.
IIRC, escom ignores it, so it should be easier than other way round.
If it has the same symptoms, at least CIA chips are ok.
then you can run X-copy on A1200 to test drive.
recalibrating is fiddly, but not too hard, I've done it by hand.

Thanks for the tip Orange, maybe try that. I have looked at adding a gotek, but that probably would be better in the 1200. I have been looking into getting a flash drive for the 1200 too, but then I see I cant use whdload on a stock machine, always needing more memory, accelerator, etc. All expensive items, for 2 old computers that are probably going to be stored again in the near future. For 50£ I could set up a pi with none of the issues of running this old hardware, will have to see if it's worth doing that instead.

[mastersetter]

Vampire is nice but really way too expensive for what I want or need to be honest.