ACA 500 not booting

[AmmoJammo]

pics? lol

[guest7146]

A few thoughts:

• My advice is not to complete any rework on the ACA500 unless you are happy with voiding its warranty and potentially ending up with a broken board that cannot be returned regardless of why it's faulty.  If you have problems it would be best to talk to AmigaKit (I assume that's where you bought it?), who will be able to advise further.
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• Regarding the 'suspect' solder joints, these are through-hole joints and will be plated through.  As long as there is a sound joint on the top-side then an electrical connection is made and you can rule this out as being the cause of any fault.

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• The fact that the power LED goes off suggests a power problem.  Either a problem with your supply in terms of its ability to supply current, or a short circuit on the 5V rail when your expansion board is connected.  The third pin down on the expansion edge connector is VCC.  Also you can get to VCC via pin 4 of the 8-way keyboard connector.  With the ACA500 disconnected I would measure the resistance between VCC and ground.  Then plug in the ACA500 and, without applying power, try to measure between VCC and ground again.  This might help you determine whether a short circuit condition is being applied to the edge connector.
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• You could also try measuring the voltage at VCC with the ACA500 disconnected and the Amiga powered ON.  Then connect the ACA500, power the Amiga ON, and measure VCC again.  It would be interesting to see what's happening to the 5V rail.  I kind of doubt that it's being completely shorted to ground because then I wouldn't expect the CPU to be able to run ANY code, and I guess it is at least running its self-test because it's reporting errors to you via the coloured screens.

Out of general interest:

The power LED should illuminate immediately as the 5V is applied. The only control that the Amiga exercises over the power LED is a switched dimming of the LED which it uses for error reporting.  Otherwise, as long as 5V is present and the keyboard is plugged in, you should have some kind of power illumination.  The only condition under which the power LED does not illuminate at all is a problem on your 5V rail.

[spirantho]

Only the later revisions dimmed the LED. The earlier versions turned it off instead. In this case, it's starting up but crashing before it's turned on the power LED. If he had no 5V, he would have no display at all and the Caps Lock light wouldn't work.

It's a CPU problem. probably a bad connection stopping the CPU connecting to the motherboard, so it's waiting for the chipset to acknowledge, and it's never happening so it's stuck waiting all the time.

[Chartus]

I just started a return authorization ticket with AmigaKit.  Looks like I will have to wait another month or 2 before I can enjoy my 500.

I hate floppies.

Oh yeah... no pics of my A600 ....well maybe...hmmm... no

[duga]

Have you tried without Kickstart on the motherboard?

[guest7146]

Only the later revisions dimmed the LED. The earlier versions turned it off instead. In this case, it's starting up but crashing before it's turned on the power LED. If he had no 5V, he would have no display at all and the Caps Lock light wouldn't work.

It's a CPU problem. probably a bad connection stopping the CPU connecting to the motherboard, so it's waiting for the chipset to acknowledge, and it's never happening so it's stuck waiting all the time.

That's good information - I didn't know that! :hat:

For my understanding, would this be the model that had the red power LED? I never owned one of those.  My A500 has a green power LED, the same as the A500+.

In light of the information you have given I agree; it sounds unlikely that this would be a problem on the 5V rail.

[spirantho]

It will almost certainly have a red LED, yes. My first A500 was like this

[Chartus]

Yes both of my A500s have the red power led.   Probably a higher number of 500s in the US are earlier versions in comparison to the EU  versions.

I wish I could get an A500+ MB

I read that you could take out the Kickstart chips and it would still boot.  I might try that just for kicks.

I think the bad solder job with the edge connector is probably not the problem it's just not something you like to see when you get a new part.

[lantus360]

I am reporting the exact same issue on my ACA500 - i am running A500 Revision 5 mobo. I have a ticket open with Amiga kit but they are just telling me to clean the connectors. I have done that of course but it does not work - i get the exact same black screen as what you are experiencing. It wont boot.

Now whats interesting is i can get to the boot screen if i attach an ACA1232 but most of the time it wont boot to CF and locks up. Right now my ACA500 is rather worthless. The ACA1232 is working incidently as its been tested in my A1200.

Incidently my solder joints are horrible also - it looks like it was hand soldered and could be a refurbed unit. Here is what mine looks like.

[Chartus]

They told me to clean my connecters also.  I tried with an eraser but it didn't have any affect.  I will make a trip to Austin on Friday an pick up some chemical cleaner and try that.  I really don't want to ship it back because that would be a pain.

You have a A1200 .  Why are you messing with an A500

[Damion]

I know it works without the ACA connected, but have you re-seated the socketed chips inside the computer? Simply giving them all a firm push until they stop making "crunch" noises is usually enough.

[Methuselas]

Glad I opted out of buying one of these. I always thought it was sub-par performance, but owning a rev 5 motherboard, I'm glad I avoided it, all together.......

Sorry for you people that got duped into buying one.

[Chartus]

I was looking forward to using my 500 and have a little extra speed.  Too bad it doesn't work with my rev 5 MB.  

oh well...I guess I will start working on my second A600.  I need to replace all of the caps on it.

ACA 500 goes back in the box.  I might get another MB if I can find a later revision.

[joekster]

I can pretty much confirm the a500/rev5 compatibility problem. I have 3 rev5's and none of them work with the aca500... They all work with other side expansions and have perfectly clean connectors.

[Chartus]

I looked on the BBOAH site and I found out that mine is a rev.5 type 2

I think.  That picture matched my MB layout.  Commodore made some weird tweaks to the MBs

[lantus360]

yep, ive tried everything here

- eraser
- IPA board cleaner
- Reseated all chips

as for why? Well i have an Indivision ECS and an ACA1232 board. I wanted to implement Indivision ECS chunky mode in my ports. Looks like ill be waiting a while before that happens now :\