Just drove 101 miles to pick up an Amiga 500

[Zap!]

Long story short, it was listed as untested. A couple about 70 came in an SUV and met me in a parking out. They said it was their son's, who are now 45 and 49, and it's been sitting in their attic for decades. They said it powers on, but they can't test it. It just comes with what's in the pics. I'll power it on as soon as I finish this post and eat. I paid $200, btw.

 

They also had an Atari 1200 XL, Atari 7800 Pro System, and a couple of other things. The only other thing I bought was a weird 70's computer that seems to be in kit form. It's still in my trunk, but will post pics if requested. I paid $20 for that.

 

Looks clean from what I can see, but I'm far from an expert. So, does anything stick out? I will first check the expansion for a batter and leakage. Is there any way to test this today? I have a PVM and an Atari SC1435 RGB's. Looks like I'll have to order one. Anyway, here are the first few pics. I'll be back here within the hour...

[Zap!]

Hmm, isn't there supposed to be a metal housing protecting the RAM expansion? This has none. Battery unfortunately has leakage, but that was expected...

 

So, just tried a composite cable plugged into the mono port (I had mis takingly thought it was an audio port before I read that it's composite b&w). Anyway, nothing. A greyish signal of some sort changed on my monitor, but nothing else. I tried a disk (that may or may not be working). Nothing, although I hear the disk slide when powered on, but no boot. No power LED either, just the screen turning to that grey color.

Edited August 6, 2022 by Zap!

[Zap!]

It's alive! Without the RAM expansion, it fully powers on! Hmm, so what next?

 

[+OLD CS1]

1 hour ago, Zap! said:

Hmm, isn't there supposed to be a metal housing protecting the RAM expansion?

Not all of them do.

 

1 hour ago, Zap! said:

It's alive! Without the RAM expansion, it fully powers on! Hmm, so what next?

KS1.3 is great for games.  Plenty of options.  Gotek and disk images.  Internal hard drive and accelerators.  Plenty of options.  Do you know what motherboard version is in the system?

[Zap!]

Good news, after pulling the battery, it cleaned up real nicely with vinegar to neutralize the acid, and them some alcohol to finish cleaning. Seems like the corrosion isn't bad. Put the board back in and it powers up! I guess the acid was affecting something before when I had no screen. Hmm, either that or it was off pin somehow.

 

Anyway I ordered a battery holder and an SDBox (I'm rushing things, I know). Tried to order an RGB SCART but the cable store I always order from (CoolNovelties) is on vacation until mid-August.

 

So what else? Should I take it apart and snap some pics? Anything else I need to order? Disks? I have several joysticks, btw, so I won't be needing that.

[Zap!]

10 minutes ago, OLD CS1 said:

Not all of them do.

 

KS1.3 is great for games.  Plenty of options.  Gotek and disk images.  Internal hard drive and accelerators.  Plenty of options.  Do you know what motherboard version is in the system?

No I don't, but I think it would be a good idea for me to open it up in the morning, as I would like to give it a good cleaning anyway. I will keep you posted with pics. Just researching a ton before I go to bed.

[Keatah]

That doesn't seem to be a Commodore-branded memory card. The C= ones come with a metal shield.

 

And to get it working, you'll need to do some more thorough cleaning. If it was myself, I'd remove the RAM and inspect and repair the traces underneath. Pretty much guarantee there's shorts and corroded traces there. Them vartabombs are relentless and extraordinarily reliable. Nearly a 97% kill rate. The surviving boards are the ones that have undergone extensive rehabilitation.

[Zap!]

5 minutes ago, Keatah said:

That doesn't seem to be a Commodore-branded memory card. The C= ones come with a metal shield.

 

And to get it working, you'll need to do some more thorough cleaning. If it was myself, I'd remove the RAM and inspect and repair the traces underneath. Pretty much guarantee there's shorts and corroded traces there. Them vartabombs are relentless and extraordinarily reliable. Nearly a 97% kill rate. The surviving boards are the ones that have undergone extensive rehabilitation.

Yup, it worked after I removed the corroded battery and gave it a thorough cleaning.

[Keatah]

Very good then. If you have any wonkiness going on later, that's the first place to start. Otherwise it looks like a clean machine. What revision motherboard?

[Zap!]

Just now, Keatah said:

Very good then. If you have any wonkiness going on later, that's the first place to start. Otherwise it looks like a clean machine. What revision motherboard?

BTW the board says "MicroNotics 1987" on it under closer look. Is that an aftermarket board? Sure wish I had a Sysinfo disk. I don't know the revision, but I'm going to open it in the afternoon when I wake up. Will post pics.

[Keatah]

Must be.. It's not a C= board.

http://amiga.resource.cx/exp/m501

http://amiga.resource.cx/exp/a501

[Keatah]

For added longevity, try some vinegar to neutralize the acids. When I do such repairs I also replace copper strips and ensure nothing's going on on the inside of the board (multi-layer). Then I coat over with a conformal coating or epoxy or lacquer nail polish. that shit's insidious.

[Keatah]

1 hour ago, Zap! said:

Good news, after pulling the battery, it cleaned up real nicely with vinegar to neutralize the acid, and them some alcohol to finish cleaning. Seems like the corrosion isn't bad. Put the board back in and it powers up! I guess the acid was affecting something before when I had no screen. Hmm, either that or it was off pin somehow.

OK I see you did that. The acid is both conductive and capacitive. Even generates power all by itself. Yup. And that's sure to mess up RAM signals. And messes up low-power CMOS stuff more like RTCs and BIOS settings memory on PCs.

Edited August 6, 2022 by Keatah

[Zap!]

Here's how it looks after just the vinegar and alcohol, and gentle scrubbing. Do you think I need to add a coating? 

[Zap!]

Here's the mouse, btw. No yellowing, must have really been packed tight in that attic!

 

 

[Keatah]

I would install a NiMH battery, 3.6v, same size. That'll keep the RTC running.

 

The discolored masking tells me there is acid under it. Hard to say if its neutralized or not. When I see that shit I remove the green insulating masking and the green/black corroded pieces of the traces. Replace with bodge wires or strips of copper.

 

You don't want to seal anything with a coating until it's cleaned and dried. Several 4 or 5 days. Or bake it in the oven at 170`F for a couple of hours. It may work now, but in 3 years? 5 years? Who knows.

 

There's a bit of shit left on the capacitor above IC with datecoded 8933. I'd address that and insure none has gotten into the capacitor itself. I just replace those.

 

I almost promise you if you try reflowing (which I do in this case) the IC's for fun, you'll see this brown stuff form up in the flux. That's because acid is inside the solder, look with a microscope to see it. Trust me it's there.

 

It all sounds like a lot, and it is. If you don't wanna go through all that, then just hope for the best, and at the first sign of weird behavior do all the above or replace the board. They can't be that expensive and I will guess there's modern replacements sporting even moar memory. Not an Amiga repair person, but these are techniques and methods that apply to commercial hobby-grade 'tronics. Automotive and Aerospace is a whole different ballgame and beyond the scope of what we're doing here.

 

But most of all enjoy the machine and build up a set of tools and utilities and games. I'm not a fan of accelerators unless they're very full-featured and can have their speed set to original. But I am a proponent of and advocate purchasing a modern storage solution - of which there are several to pick from.

Edited August 6, 2022 by Keatah

[Atariboy]

This video might be of some help if you want to dig deeper to try to stop future corrosion like Keatah recommends.

 

 

[Zap!]

7 hours ago, Keatah said:

I would install a NiMH battery, 3.6v, same size. That'll keep the RTC running.

 

There's a bit of shit left on the capacitor above IC with datecoded 8933. I'd address that and insure none has gotten into the capacitor itself. I just replace those.

 

I almost promise you if you try reflowing (which I do in this case) the IC's for fun, you'll see this brown stuff form up in the flux. That's because acid is inside the solder, look with a microscope to see it. Trust me it's there.

I actually ordered a CR232 battery holder, and it's coming from the UK.

 

I'll clean the cap more. Not sure that I have the means or skills to completely restore it, but I'll look into it.

 

7 hours ago, Atariboy said:

This video might be of some help if you want to dig deeper to try to stop future corrosion like Keatah recommends.

 

 

Interesting. All I did was pour a little vinegar on it last night, scrub, and then followed with alcohol. No water. I'll try this method of soaking with the vinegar, then water and alcohol. I won't do just yet is that intense scrapping that he did (and wiring mods). His seemed more corroded anyway than mine. As I trye, it's soaking in vinegar for an hour. Thanks!

 

So while I wait for the SDBox and battery holder, what to do next guys? Cleaning and opening in a little while.

Edited August 6, 2022 by Zap!

[Keatah]

Since that Cr2032 isn't recharchable, what are you going to do about the charging circuit that formerly charged the NiCd battery?

[Zap!]

1 hour ago, Keatah said:

Since that Cr2032 isn't recharchable, what are you going to do about the charging circuit that formerly charged the NiCd battery?

Not sure, but this is what I ordered:

 

https://www.ebay.com/itm/154520476301?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=TrdFe4T4TpO&sssrc=2349624&ssuid=_65O1jNOS96&var=&widget_ver=artemis&media=COPY

 

Anyway, here are pics of the motherboard. See anything interesting?

 

[+save2600]

The coin cell adapter you bought from AmigaKit includes the diode needed to prevent the charging circuit from blowing up your battery.  ??

 

You've got an older Revision 5 mobo there, and an 8370 512k Agnus chip which is unfortunate if you want to run PAL software without chopping off the lower 1/5 of the screen. Or ability to run some PAL software at all or without corruption. 

 

There's a simple mobo hack that allows 1mb of ChipRAM that I'd recommend doing*. See the interwebs for details on that. 

 

*And/or skip the hacks + Kickstart upgrade (do still replace Agnus with an 8372 chip - this is important) and just get an Indivision ACA500 sideport accelerator and expansion system later for a real capable Amiga computer and games experience:  

 

https://icomp.de/shop-icomp/en/shop/product/ACA500plus.html

 

There's modern internal accelerator + CF<>IDE options today too which are nice, but are much more involved. Need to get a 68000 CPU relocator, update your Kickstart, etc. The ACA500+ is basically plug and play. Excellent bit of hardware.

 

 

 

[Zap!]

38 minutes ago, save2600 said:

The coin cell adapter you bought from AmigaKit includes the diode needed to prevent the charging circuit from blowing up your battery.  ??

 

You've got an older Revision 5 mobo there, and an 8370 512k Agnus chip which is unfortunate if you want to run PAL software without chopping off the lower 1/5 of the screen. Or ability to run some PAL software at all or without corruption. 

 

There's a simple mobo hack that allows 1mb of ChipRAM that I'd recommend doing*. See the interwebs for details on that. 

 

Maybe update the Kickstart chip to 3.1 if you want. 1.3 can run PAL software just fine, but can't switch between modes easily without software to do so. 3.1 allows easier switching at the early startup menu, but can break compatibility with some games at the same time. If you're sticking with a floppy based system and as OLD CS1 alluded to, I'd be tempted to just leave 1.3 in there. 

 

*And/or skip the hacks + Kickstart upgrade (do still replace Agnus with an 8372 chip - this is important) and just get an Indivision ACA500 sideport accelerator and expansion system later for a real capable Amiga computer and games experience:  

 

https://icomp.de/shop-icomp/en/shop/product/ACA500plus.html

 

 

 

Thank you for all the info! So it's an older Rev 5? I will look into that hack. That Indivision ACA500 looks awesome! I will strongly consider!

 

Anyway, deep cleaning now, including the mouse. Might take 24 hours to dry and get all those damn keys back in there. ?

[+save2600]

I edited my response above to remove the Kickstart 3.1 blabber. On second thought, I'd really only upgrade Kickstart on such a machine if you plan on adding an internal accelerator. Otherwise and as mentioned, Kickstart 1.3 is super capable and super compatible.  ?

 

The ACA500+ adds an entirely new dimension to such a setup though. So if later you want to experience WHDLoad, a better Workbench experience and the (large) handful of games that benefit from acceleration - something to look forward to. 
 

BTW: I wouldn't let the keys (or anything) dry on its own. You're likely to leave tiny but visible water spots, and water in the tiny key cap stem holes! Toohtbrush/washcloth and dish detergent to clean, water to rinse and a hair dryer to fully dry after you've blotted "dry" with a cloth... is a best practice of mine.  ?

[+save2600]

 

 

 

...yep, Rev. 5. Not that there's anything wrong with it. ?

[Zap!]

5 minutes ago, save2600 said:

I edited my response above to remove the Kickstart 3.1 blabber. On second thought, I'd really only upgrade Kickstart on such a machine if you plan on adding an internal accelerator. Otherwise and as mentioned, Kickstart 1.3 is super capable and super compatible.  ?

 

The ACA500+ adds an entirely new dimension to such a setup though. So if later you want to experience WHDLoad, a better Workbench experience and the (large) handful of games that benefit from acceleration - something to look forward to. 
 

BTW: don't let the keys (or anything) dry on its own. You're likely to leave tiny water spots! Toohtbrush and dish detergent to clean, water to rinse and a hair dryer to try after you've blotted "dry" with a cloth is a best practice of mine.  ?

Thanks, right now the first thing I need is to get an RGB SCART. That b&w composite is rough!  Looks like I made a mistake by ordering an SDbox, right? I asked the store owner if I can cancel.  I actually have one Amiga game called Amberstar. I can test when it's put back together.

 

Thanks for the drying tip. I will dry right after this post. I already used laundry detergent. Hope it's ok, but I've done this many times before without problems. I am also one of the few people who use bleach. This horrifies some who have never used it on old cases, but I have been doing this for years, even on black hardware.