A590 power supply schematic

[fiat1100d]

Hello!

I have the A590 service manual but it lacks information about the power supply... Does anybody know where can I find a schematic? My unit is giving out about 20V on the 5V line :-o

[rkauer]

 That doesn't sound good.

 Try to use your A590 without the PSU, only the A500 unit and measure the A590 connector again.

 If no-go, ask it again I'll find some pages to you.

[leofoe]

As fas as I know you can use a PSU from a CD32 directly or from an Amiga 500/600/1200 PSU by replacing the connector.

[orange]

or any other +12V, +5V PSU for that matter.
just leave the "power on sense" pin not connected.

[fiat1100d]

rkauer wrote:
 That doesn't sound good.

 Try to use your A590 without the PSU, only the A500 unit and measure the A590 connector again.

 If no-go, ask it again I'll find some pages to you.

I am not sure I understand you... The A590 won't work without its PSU, it only gets from A500 a "power sense" signal (which is the 5V from A500 PSU, when it turns on) and of course GND connections. Since my A590 PSU was frying fuses and ICs, I tested it without equipment attached and measured more than 19-20V, then I though it could need a load and attached a power resistor but voltage dropped to only 15V...
I think it could be a PWM regulator (3524) inside the unit which may have gone bad, but if I find a proper schematic it would be better.
I may decide to power the A590 directly from A500, it's just a matter of soldering a couple of wires (I already use a bigger AT PSU on A500), but if I manage to repair original PSU it would be better
(got this A590 NEW in box from a dealer who had lot of surplus, some years ago)

[Zac67]

That PSU probably fried close to everything on the A590...  :-(

A good chance to switch to the PC PSU. It may be an original part, but it's hardly worth bothering otherwise. I don't think schematics for it are around; C= (OEM?) used to constantly change those things slightly.