Amiga 500 boot issues

[dbain21]

I have a "spare" Amiga 500 that I haven't tested in quite a while. The system powers up and I hear the floppy drive being accessed (although the sounds are pretty faint). No red light for the drive access and no video. I removed the A501 expansion card. The battery has leaked so I will remove that and attempt to clean the PCB. All of the chips appear to be seated properly.

Please advise regarding next steps to troubleshoot this system.

Sincerely
Derek

[eliyahu]

@dbain21

although i can't help you here, i would like to welcome you to the site. welcome to amiga.org!

-- eliyahu

[jdupuis]

I have a "spare" Amiga 500 that I haven't tested in quite a while. The system powers up and I hear the floppy drive being accessed (although the sounds are pretty faint). No red light for the drive access and no video. I removed the A501 expansion card. The battery has leaked so I will remove that and attempt to clean the PCB. All of the chips appear to be seated properly.

Please advise regarding next steps to troubleshoot this system.

Sincerely
Derek

Hi,

First order of business. Visual inspection is non distructive. Closely inspect the A500 motherboard for leaking capacitors. Electrolytic caps will have a powdery look at the base of the legs or the top will bulge if they are leaking or bad. Ceramic disc caps will be burnt or cracked. Bad traces. Cold solder joints. Loose chips (found by pressing down on them). There is also a weird thing that takes place with socketed chips - leg corrosion (you can't see). Simply and very very carefully removing these chips and reinstalling them mysteriously fixes enigmatic problems. Same for the floppy connectors and keyboard connection. Agnus is a PLCC chip. Hard to remove carefully without a PLCC chip puller but it can be done. Pull up and out carefully and evenly. Same with the other chips. Hope this gets you in the ball park to troubleshoot further. Side note - The RF composite video RCA connector is not very reliable. An A520 or a monitor connected to the RGB connector is the best way to go. We all know this I am just throwing it out there. Leave your 501 expansion out as you troubleshoot. Focus on the A500. Get it going, then work on the 501. One thing at a time.

Cheers!!

[jltursan]

Welcome aboard!

...and, what about some pics to see what's about this A500?, motherboard rev (probably a rev.8?), visual damages and so on...

[Oldsmobile_Mike]

It's not super-clear from your post.  Is this a regular A500, or an A500 Plus?

[dbain21]

@jdupuis - Thank you for the detailed response. Other than installing and removing expansion cards in various systems, I can't say that I have any experience with some of the other items that you mentioned with the exception of replacing a CPU fan and processor on my laptop several weeks ago.

I'll post a few photos of the current condition of the system later this evening if time permits. Perhaps that will assist with diagnosing the issue(s).

[dbain21]

@Oldsmobile_Mike  - it is an Amiga 500 (I'm not familiar with the Plus or how to distinguish that model from a 500 ?) I will attempt to upload a few photos later this evening.

[Oldsmobile_Mike]

@Oldsmobile_Mike  - it is an Amiga 500 (I'm not familiar with the Plus or how to distinguish that model from a 500 ?) I will attempt to upload a few photos later this evening.

https://en.wikipedia.org/wiki/Amiga_500_Plus

Is the battery on your motherboard, or on your RAM expansion board?  If it's on the RAM expansion board, then it's irrelevant to your problem for right now since you can just remove the entire board.  That was the question, LOL.    In any case, sounds like it's a plain A500, go with the above - check all the socketed chips for looseness, etc.  

[dbain21]

Here are the photos from my Amiga 500 - Rev 6a. None of the chips appear to be loose. Battery leak / damage is clearly visible on the third image (the A501 expansion board). I did not notice any capacitor leaks but I am not an expert in this area.

[ATTACH]4801[/ATTACH]

[ATTACH]4802[/ATTACH]

[ATTACH]4803[/ATTACH]

[ATTACH]4804[/ATTACH]

[ATTACH]4805[/ATTACH]

[Oldsmobile_Mike]

Try it without the ROM switcher.

[dbain21]

@oldsmobile_Mike - where is the ROM switcher located?

[Oldsmobile_Mike]

@oldsmobile_Mike - where is the ROM switcher located?

Um, it's that huge ribbon cable and circuit board sticking out your ROM socket. Remove that whole mess. Just stick one ROM directly in the socket. Test that way.

[dbain21]

Sorry for the delayed response. I removed the ribbon cable and circuit board as suggested and plugged one ROM directly into the socket. Tried both ROM's, no luck, same problem as before. I also pushed down on all of the internal chips (I did not remove and re-seat them). Any other suggestions? If someone was looking to buy this system for spare parts or to try to resurrect it, what is a reasonable asking price? (system includes the extra ROM and expansion board, no power supply, no peripherals).

[Oldsmobile_Mike]

You probably ought to at least reseat the Agnus, because of this:

http://eab.abime.net/showpost.php?p=91131&postcount=3

Even if you decide to sell it, you'll get more for a "tested, working" system than for one with "unknown issues".  Or the scammer's favorite on ebay "untested, sold as-is", haha.  

[dbain21]

thanks I will try that and post the results :bump: