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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Laughy on July 14, 2013, 08:01:44 PM

Title: A500 PSU problem!
Post by: Laughy on July 14, 2013, 08:01:44 PM: Hello,

I need a little help.

Just turned on my Amiga, to try out a game. It booted fine, had a quick go. Then I heard a shorting out noise from one of the plugs, noticed that the Amiga had no power light!

Pretty sure that the PSU is shot, turned it all off, pulled out the PSU from the Amiga and tested the pins. Get absolutely no readings from any of the pins.

Does this mean that I will need another PSU?

I am going to take the Amiga to a friend's during the week, to use his PSU to see if there has been any damage to the Amiga's chips.

Thanks for any advice anyone can give!!
Title: Re: A500 PSU problem!
Post by: vince_6 on July 14, 2013, 09:51:05 PM: Check your Amiga with your friends PSU and if it works then make a simple cable to power your machine via an ATX PSU. There are many schematics on the internet, choose the simplest one without custom boards (just rewiring)

Good luck!
Title: Re: A500 PSU problem!
Post by: sim085 on July 14, 2013, 10:20:47 PM: I do not know about other countries, but UK plugs have a fuse in them ... maybe this fried up and the psu is ok (given the sound came from the plug not psu)
Title: Re: A500 PSU problem!
Post by: curtis on July 15, 2013, 01:24:39 AM: simo85 is correct. First check for a fuse.

Second, the A500 power supply is a switching power supply meaning if there is no load on it, it doesn't put anything out! Just turn on the power supply and check pins with nothing plugged in and you'll probably get no readings.

If you have a test bed/motherboard (don't we all?) you might plug the power supply into it and try getting readings at the plug on the motherboard.

Better yet, if you've got a motherboard that's bad, but you're keeping as a chip and parts source, plug it into that! As long as there's some sort of load on the power supply, you'll get voltages.

Good luck!

Curtis
Title: Re: A500 PSU problem!
Post by: Laughy on July 15, 2013, 09:35:36 PM: Thanks everyone!

I changed the fuse, and plugged back into the Amiga, but nothing happened. Strange as you say sim085, because the sound came from the plug..

I will hopefully be able to pick up the PSU tomorrow or Weds..fingers crossed!
Title: Re: A500 PSU problem!
Post by: Laughy on July 16, 2013, 05:52:44 PM: I got the PSU from a friend, it works! I just wonder if there is anything I can do to fix my own, or should I just buy a new one from Amigakit? They aren't too expensive..
Title: Re: A500 PSU problem!
Post by: curtis on July 16, 2013, 10:32:36 PM: If you're handy with a soldering iron and pretty good at electronics, a power supply is USUALLY fairly easy to repair. If not, Amigakit...

Quote from: Laughy;740952
I got the PSU from a friend, it works! I just wonder if there is anything I can do to fix my own, or should I just buy a new one from Amigakit? They aren't too expensive..
Title: Re: A500 PSU problem!
Post by: Laughy on July 17, 2013, 02:04:18 AM: Quote from: curtis;740982
If you're handy with a soldering iron and pretty good at electronics, a power supply is USUALLY fairly easy to repair. If not, Amigakit...

Thanks, I'd give it a go, it can't get any worse!! How hard could it be...I have seen a few PSU's on ebay, so I'm going to try to get one of those.
Title: Re: A500 PSU problem!
Post by: mechy on July 17, 2013, 02:37:10 PM: Quote from: Laughy;740805
Hello,

I need a little help.

Just turned on my Amiga, to try out a game. It booted fine, had a quick go. Then I heard a shorting out noise from one of the plugs, noticed that the Amiga had no power light!

Pretty sure that the PSU is shot, turned it all off, pulled out the PSU from the Amiga and tested the pins. Get absolutely no readings from any of the pins.

Does this mean that I will need another PSU?

I am going to take the Amiga to a friend's during the week, to use his PSU to see if there has been any damage to the Amiga's chips.

Thanks for any advice anyone can give!!

It could be a case of the wiring has shorted/broken inside the 5 pin square din plug. it does happen from years of use sometimes.

Mike
Title: Re: A500 PSU problem!
Post by: Laughy on July 20, 2013, 07:14:55 PM: Thanks Mechy,

I haven't looked yet, but is it possible to buy a replacement 5 pin plug and cable? And then just wire it back up to the PSU?
Title: Re: A500 PSU problem!
Post by: Coolhand on July 20, 2013, 09:11:01 PM: http://www.ebay.co.uk/itm/Amiga-power-lead-plug-ideal-for-towers-and-projects-good-condition-used-/121133762365?pt=UK_VintageComputing_RL&hash=item1c3422873d
Title: Re: A500 PSU problem!
Post by: Laughy on July 20, 2013, 09:27:00 PM: Thanks Coolhand!

That's great, and a real kick in the teeth, as I just bought a game from that guy! Then my PSU stopped!! Never mind!!
Title: Re: A500 PSU problem!
Post by: Laughy on September 15, 2013, 10:08:28 PM: Just in case anybody was bothered, just thought I'd let you know I finally solved the issue with the PSU...

It turned out to be the 400mA fuse! To my untrained eye it looked alright, so never tested it..oh dear it would have saved a lot of time! But never mind, live and learn, and at least I can now enjoy using my Amiga again!

Happy days!