A4000D Power Supply upgrade question

Magic · 31 January 2018, 17:59

I am working on installing an ATX power supply in to the A4000's power supply case. I have it all done and I am testing my voltages at the A4000 motherboard plug. I am not getting the 5 volt "power good" signal on the gray wire. It is only showing about 200 millivolts. Could it be that it won't supply the "power good" signal without a load connected? All of the other voltages are within spec. I wanted to resolve this before plugging it in to my A4000D's motherboard.

Thank you for any ideas.

alexh · 31 January 2018, 18:18

Yes it needs a load connected.

Here when we want to use an ATX PSU and no motherboard (say for powering a custom device) we use a special load connected to a HDD molex and jumper the ATX connector green wire (PIN 16 POWER ON) to a black wire (PIN 17 GND) to turn it on.

In the old days we used to use HDD's as the load but newer PSU's don't turn on with only a single HDD for load

Magic · 31 January 2018, 21:44

You are correct! Once plugged in it works great. My A4000D - Mediator 3.3 - Sonnet machine now has a modern 450 watt power supply. Thank you for the fast reply.

[EDIT] The machine feels more stable and responsive now. The system fan doesn't slow down every time a CD spins up anymore either. The Mediator - Sonnet combo seems to be stable now too.

31 January 2018, 17:59	#1
Magic Registered User Join Date: Aug 2007 Location: USA Posts: 359	A4000D Power Supply upgrade question I am working on installing an ATX power supply in to the A4000's power supply case. I have it all done and I am testing my voltages at the A4000 motherboard plug. I am not getting the 5 volt "power good" signal on the gray wire. It is only showing about 200 millivolts. Could it be that it won't supply the "power good" signal without a load connected? All of the other voltages are within spec. I wanted to resolve this before plugging it in to my A4000D's motherboard. Thank you for any ideas. Last edited by Magic; 31 January 2018 at 21:59.

31 January 2018, 21:44	#3
Magic Registered User Join Date: Aug 2007 Location: USA Posts: 359	You are correct! Once plugged in it works great. My A4000D - Mediator 3.3 - Sonnet machine now has a modern 450 watt power supply. Thank you for the fast reply. [EDIT] The machine feels more stable and responsive now. The system fan doesn't slow down every time a CD spins up anymore either. The Mediator - Sonnet combo seems to be stable now too. Last edited by Magic; 01 February 2018 at 17:54.

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31 January 2018, 18:18	#2
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,337	Yes it needs a load connected. Here when we want to use an ATX PSU and no motherboard (say for powering a custom device) we use a special load connected to a HDD molex and jumper the ATX connector green wire (PIN 16 POWER ON) to a black wire (PIN 17 GND) to turn it on. In the old days we used to use HDD's as the load but newer PSU's don't turn on with only a single HDD for load

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