Old A500+ issue..

[scuzzb494]

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

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 ]

[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

[mechy]

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

Nice work,you need to neutralize that leakage with vinegar or some such then clean it well with isopropyl alcohol or it will continue eating traces.
you can de-solder any chip and replace it on that board, all common ttl parts(if you have the skill).

[scuzzb494]

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

I admire all your efforts. I just wish I had that level of expertise with electronics. It really is just magical to see the Amiga back up and running. Well done.

I took the easy way out today and just swapped out the motherboard. She was the only one that I just couldn't get working.

http://www.scuzzscink.com/amiga/scuzzblog_november17/scuzzblogdnovember17_1001.htm

If you check out the blog I've done several pages on the 500Plus computers that I checked. Like I say the one above was the worst. No chance.

Anyway.. have fun. When she finally works you will feel an empty feeling. So just get yourself another challenge. Mend some more. Seriously... well done.

[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!!

[stefcep2]

Vinegar?  Why vinegar?  Vinegar is water and acetic ACID.   We have battery ACID leaks causing corrosion, yes?  How does adding more ACID help?

I used baking soda and a tooth brush.

[zipper]

Because the batteries are alkaline, elementary!

[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.

[orange]

nice work.
about the floppy drive, try cleaning the two sensors (disk_present+writable) with alcohol.

[mastersetter]

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

[orange]

then try recalibrating it, do you have another Amiga or working external fdd?

[mastersetter]

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

[Oldsmobile_Mike]

Looks great!  What in the world is that model of joystick off to the right?

[scuzzb494]

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!!

Did you neautralise the vinegar. I dilute my vinegar and then use liver salts [ Andrews ] which contains sodium bicarbonate. [ baking soda ] . Another use for these two items is to create your own mini vulcano. Mostly the combination turns to water in the form of bubbles. Dry very carefully.

Also return to your work on a regular basis to see if there is any further damage.

Problems are not just Amiga related by the way....

http://www.scuzzscink.com/amiga/scuzzblog_november17/scuzzblogdnovember17_1702.htm

http://www.scuzzscink.com/amiga/scuzzblog_november17/scuzzblogdnovember17_1704.htm

[orange]

@mastersetter
I take it you don't have HDD+controller either?

@mike
I have exact same joystick, bought it brand new few years ago from Vesalia:
 http://www.vesalia.de/e_cruisercolour.htm