A1200 boot problem - help!

[mongo]

Ok, I pulled the PSU and opened it up.

http://www.flickr.com/photos/blakespot/4856309117/in/set-72157604300573758/

Leaky caps, and two smaller caps are slightly bulged...

So I've got a working, standard ATX PSU in there all wired up, but the PSU that came with this Mediator A1200T case from Revanche LLC has a little two-wire line running out that ties to the front of the case power switch (since it's not gonna detect it from the mobo, as it would with a PC).  

What do I do to get this standard ATX supply to soft-switch on?  The little line runs under the board of the old PSU and I'm not too keen on handling the board directly to see where it runs.  Is there a way to wire something up to the main ATX header (which is not being used on this Amiga setup)?

Thanks.




blakespot

Connect pin 14 (Green wire) to GND (Black wire) to turn it on.

[mongo]

Check here for connector Pinouts...

http://pinouts.ru/Power/atx_v2_pinout.shtml

DONT ground the purple wire that +5v...

The Pinouts on this Schematic and my own one use PIN 16 not 14 !!!

Pin 14 on a 20 pin ATX connector (v1.x) = Pin 16 on a 24 pin ATX connector (v2.0+).

Just use the green wire, whatever pin it is.

[mongo]

Hm.  Ok, I see you can tie the PWR ON (green cable) to GND permanently and you're set, if your PSU has a physical switch, as mine does. I did this, but I just get a blip of power on this replacement PSU.  Power light comes on for just a sec.  I untied the lines and just touched them for a moment, in case it was a toggle w/ a short window -- no better luck.

This PSU worked fine in a P3 700 tower I don't need anymore.  Did it coincidentally die just now?

There's no way the A1200 w/ one HD and 060 accel is drawing more power than that P3 system.

Thoughts?  Thanks.



blakespot

Check for +5v on the purple wire. It should be there even when the power supply is off.

If you have a brown wire (+3.3v sense) on pin 13, connect it to one of the orange ones and see if that solves your problem.

[mongo]

Can you explain what that's about, the orange / brown connection?

Thanks



blakespot

The orange wire is +3.3v, the Brown wire is the +3.3v sense line. The sense line is used to monitor the voltage at the motherboard and is normally connected to +3.3v. If the sense line isn't getting any voltage, the power supply might determine that something is wrong and shut itself down.