A4000 ATX PSU problems

[amiga4001]

I have got me a A4000D with cyberstormppc mediatorwith all ports filled and a buddha flash with the delfina(which workes nice now) and this is all stuufed into a tower with 2 cdrom drives and a ide zip drive and 2 uwscsidrives.
This was all linked to a AT PSU of 250 W I believe.
This old PSU gave problems with booting of the cyberstormppc sometimes it did and sometimes it did not.
So I tried a other PSU of same rating but this one didn't boot at all.
Now I have me a ATX to A4000 adapter with a 300W PSU(brandnew) and it still doesn't boot.
Only PSU which does the job 100% is the original desktop PSU!!
This one bootes every time and give no problems what so ever but I had to modify it so much to let the print fit into the AT case it isn't secure anymore so i'll have to find me a replacement.
Any reccomandations for PSU rating?
Is the cyberstorm taking that much drain while booting?

[amiga4001]

Ok update I tried it with the 300W ATX PSU with only the mobo connected and offcourse the cyberstromppc processorcard.
Does boot up till the diskflop animation but image is heavy dissorted.
Only way to reach this is by powering the psu up with the ps on wire to ground(as you should fire it up I believe).
But still no luck so far.
What is the difference between the two types of psu?
I mean the original 145W workes nicely and this 2 times heavier psu doesn't work?
Maybe the powergood line has a different voltage?

[Framiga]

How is done those "A4000" adapter? selfmade or . .

EDIT- theres a nice article here

http://www.aug.org.au/augmag/WB_September_2002.pdf

page 8: ATX>A4000 connector

. . . just to be 100% safe :-)

[amiga4001]

It is an original adapter which is hooked up like the schematic on the pdf file.
Only some shortcuts there is only one connection to a +5VDC instead of 3 or 4? connections with the pdf schematic.
But if it only has to boot the cyberstorm this wouldn't be the problem right?
In the meantime I also tried a AT psu of 150 W.
This one also has problems it only boots up the naked mobo and no drives attached to it.
Is the original psu capable of producing more current in a short time maybe?
Want to invest in a nice psu of 500W or so but it has to work first.
And can not understand why it won't boot with the other psu's AT/ATX of same rating or more..

[Framiga]

don't wast your money . . . theres a problem with your adapter.

Where? . . . no idea. The PowerGood is a signal thet "tell" to the mobo that the lines are stabilized and then, the power is delivered to the devices.

Are you powerON the ATX PSU from its PowerON line? or have you shorted the PowerON with the GND and you switch the rear AC button?

This is a wrong way to powerON an ATX PSU.

Take the AC switch always ON and powerON the system, trough the PowerON>GND wires via a switch.

[Brian]

The computer requiers quite a bit of +5V and +12V .. you should try get more than 1 cable to supply this to the motherboard or you might experience problems. If you look at the original PSU plug you see there are some cables that are far thicker than the other cables so that they can supply more power to the motherboard. Look at the motherboard plug of a PC and you will see that there are several cables that supply the same current, same reason.

[amiga4001]

Think there is a problem on the moboconnector also.
The thick yellow wire is getting extremely hot.
And when I switch to AGA screen instead of picasso96 it is missing colours/freezes and the ppc is freezing also after a short time.
It is the +5vdc line I think.
This was never the case before only now after I have tried these other psu I have problems with the original desktop psu.
Maybe the soldering contact has come loose on the mobo?
Got to remove all my boards and so to get to the backside of the mobo to see what is going on.
Will also try to modify the adapter to carry more load through thicker wires.
As I am comparing the original wires with the adapter wires these are extremely thin.
Let you guys/girls know if succes.

[amiga4001]

So I soldered some xtra thicker wires to the powerplug off the amiga4000.
Powered up the atx 300W supply no nothing.
measured again the voltages on the plug of the original psu and the atx and they match perfectly.
Why won't it boot with a other psu?
Same kind of problem occured in the past with a AT psu of 250W that one did boot cold but when it was running it wouldn't boot anymore.
Don't want to place 2 psu in my tower so please let me now what kind and brand of psu your using in your cyberstormppc setup which works.