A1200 boot problem - help!

[blakespot]

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

[Franko]

I was convinced that it was the PSU, I'll have to open up mine and see how I wired up the On/Off switch at the front of the case, I think it was just a simple case of the switch when grounding the purple wire from the PSU for on and leaving it open for off. Can't remember now, I'll have to open up the case and have a look. Just don't try this right now till I double check. :eek:

[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.

[Franko]

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 !!!

[Buzzfuzz]

http://pinouts.ru/Power/atxpower_pinout.shtml
 
So wire them up to 14 and 15 an that should start the ATX PSU.
 
Franko was a bit faster, this for older ATX models

[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.

[blakespot]

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

[Buzzfuzz]

Hmm, you could try to remove the SCSI kit and see if it will boot on it's own with the 1260.
Best thing is start blank and then each time add something to it, something could not be working.

[Franko]

Test the power supply without any connections made to the amiga, try just connecting the green wire straight to ground without the switch first, if the fan comes on and stays on then the PSU should be ok (no blown fuse). If this is the case then perhaps the switch your using is just a momentry switch (ie: non latching) or is faulty. Its always wise to check the PSU out first without conecting anything up first. If nothing happens open up the PSU and check the internal fuse, you might have blown it...

[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.

[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.

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

Thanks



blakespot

[Franko]

Test the power supply without any connections made to the amiga, try just connecting the green wire straight to ground without the switch first, if the fan comes on and stays on then the PSU should be ok (no blown fuse). If this is the case then perhaps the switch your using is just a momentry switch (ie: non latching) or is faulty. Its always wise to check the PSU out first without conecting anything up first. If nothing happens open up the PSU and check the internal fuse, you might have blown it...

Did you try this yet... to make sure the new power supply is ok...

[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.

[Bamiga2002]

Or you could just get an ATX to AT converter and be done with it.

[Homer]

That switch on the front is probably a momentary close action switch, i.e it's only closed when you are pressing the button. You need to keep the green and black connected to keep a ATX psu going, so that is probably the reason the psu blips on then off. Different switch required (and a temporary test with the green and black connected to ensure everything else is working).

[scuzzb494]

I had this with a hard drive on my towered A1200 and a guy pointed me to a utility called ' SlowBoot ' .

http://aminet.net/package/util/boot/SlowBoot

...The problem with buying a large IDE drive is that it has a long spun-up
time... When booting from cold you have to bootup and then reboot...
SlowBoot fixes this

May help.