A1200 random reboots and hangs - PSU issue?

[john1979]

I own a stock A1200 with an Amigakit 2.5" IDE CF and Classic WB installed.

Before I got the CF card I can't remember that I ever had this problem, although I cannot be sure since I have only had the machine a couple of weeks.

Quite randomly the Amiga will hang, reboot or just switch off completely. Sometimes this is in games but most often it is in Workbench. It could take 1 min or several hours to happen and there will be no warning. When the amiga is downgraded via relokick the reboots seem to happen less often, but still do occasionally.

Over the last few days it has been happening more frequently with complete shut offs (all leds and screen goes off) more usual.

I thought it might be bad chip memory at first but memcheck comes back clean. I also did a scan with VirusZ which came out good. Finally I checked the IDE cable connection for the cf card and this looks okay too.

I would have thought the standard PSU can handle a CF card? Is it possible the PSU is just weak or could it be something totally different?

Appreciate any ideas!

[Zetr0]

Hello John,

Powering off comes down to only one thing - the PSU.

Do you have a spare to test it with?

[john1979]

Unfortunately I don't since this is the first system I've had since I sold my 1200 in my teens.

Just to add to the powering off issue. If I don't touch anything for a few seconds the Amiga will usually kick back into life and boot again.

So it looks like the PSU is the first thing to try then. I'm just wondering what is the best way to go with this. Order a "new" one from Amigakit or get an old A500 one off ebay?

For the time being I'll remove the CF card and run completely bare bones and see if that helps.

[Zetr0]

hmmmm

well the problem with eBay is that you can run into the same problem you have now, while cheaper - its not guaranteed and could be DOA or end up as bad as you got within a few short months.

With this in mind I would plumb for one from AmigaKit, as you get perhaps the best service from a store as well peace of mind knowing if there's a problem it will be handled in the best possible manner.

Amiga Power Supply Unit (PSU) £16.33

(stock photo from www.amigakit.com)


If you have any problems or concerns you can drop 'em an eMail or pick up the phone.


Now with that out of the way, once you have a fully tested and known working power supply - should there be any more problems we can then begin to isolate known faults with the motherboard - but you need good clean power first =D

[john1979]

Thanks for your help. Ordered one! I hope it is just the PSU as it just required throwing some money at the problem to make it go away

I'll update the thread once the new PSU is in place.

[duga]

The one you have now, is it 2.5, 3.0 or 4.5A@5V?

[Foul]

if nothing change, try to find a capkit

Caps are old and can do stranges things

[john1979]

Originally Posted by duga

The one you have now, is it 2.5, 3.0 or 4.5A@5V?

I believe it is the standard 3.0A@5V 22.2W A600 PSU. I'll add a part no. when I get home later.

Originally Posted by Foul

if nothing change, try to find a capkit

Caps are old and can do stranges things

If it is this I will have to try and find a company that will work on the board for me. I'm terrible with a soldering iron!

Edit:
Just found that amigakit do a capacitor replacement service for 30 quid.
http://amigakit.leamancomputing.com/...roducts_id=932

[roy bates]

try an a500 psu ive got an a600 psu that does axactly the same thing when used on an a1200 with extra ram harddrive etc.

[john1979]

My unit is totally stock apart from the CF card and IDE adapter. No idea how many watts they use but I would have thought it'd be under 1 or 2 watts? It really shouldn't stress standard 22W PSU I would have hoped.

Anyway even though I have ordered a new one from Amigakit I am actively looking for an A500 one on ebay. Unfortunately it seems the one that does 4.5A@5V is rather rare. Everyone I have messaged so far gives me the part no. for the 2.5A@5V one which is worse than the stock A1200 PSU!

All A500 ones do manage an extra 0.5A on the 12V rail over the 1200/600 PSU, so I wonder where the power is most needed on mig's, 5V or 12?

[Zetr0]

@John1979

12v is mainly used for the sound and filtering

5v for everything else =)


while the floppy drive might take 12volts from its connector - its actually a 5 volt unit.

[roy bates]

as zetro has rightly said amigas mostly use the 5 volts rail.


it could be that your supply is on its way out,these units are very old now.

i was going to suggest hacking a pc power supply,but you have already ordered a new one.

[clauddio]

5v is for everything > the most important line
12v is only for the floppy drive in the A1200
on the A4000 also is for hardisks,cdrom

[john1979]

Well since Amigakit took some time to post out the new PSU I thought I'd have a go at the ATX conversion instructions here:

http://www.stone-oakvalley-studios.c...g/?page_id=126

The only things I had to go buy was a couple of glue sticks from the local hardware shop and a 5pin din to headphone connector (just to rip the pins from it!)

This was my first ever time soldering anything and the result was a horrible mess but it was enough to allow me to push the pins into the back of the Amiga with some wires stuck to the end of them!

Anyway the upshot is so far a cautious smile. 3 hours and no crashes. I have made it this far on the stock PSU before so anything can still happen.

[Retrofan]

Great that you have it working, but I have to say the connector is horrible, much more when you still can use an original one:

http://a4000t.com/store/index.php?ma...roducts_id=204

And I did my own guide in a post:

http://eab.abime.net/showpost.php?p=819819&postcount=89

In your place I would just change that connector.

[john1979]

Originally Posted by Retrofan

Great that you have it working, but I have to say the connector is horrible, much more when you still can use an original one:

http://a4000t.com/store/index.php?ma...roducts_id=204

And I did my own guide in a post:

http://eab.abime.net/showpost.php?p=819819&postcount=89

In your place I would just change that connector.

Thanks. On your advice I chopped the connector of the old weak supply and connector blocked it on to the ATX PSU. The setup looks a lot more safer now. As an added bonus, due to the low power draw, the fan on the Antec spins very slowly, keeping things silent.

It does feel good knowing I can expand now without ever worrying about potential power issues. No crashes or hangs yet too!

Thanks to to all who gave advice! You've helped keep another 1200 rocking

[Zetr0]

Good work John1979


I think this Amiga Hackery lark is just the thing for you =)

[keitha1200]

Nice one

You'll be able to rig-up a cd/dvd rom etc now