English Amiga Board - View Single Post - Choosing a new ATX power supply for an expanded Amiga 4000

grelbfarlk · 28 August 2019, 04:00

Well not many people run really fully loaded A4000s any more. There are a few of us, sure, but how many times do you see a post about power supplies with say, A4000D with a fully loaded Toaster System, including say, a pair of 10,000 RPM drives? They'd probably have the same problem with the Amigakit adapter.

It's like this, here's what I did with one of the Amigakit adapters:
1) Use a pin to push the little metal latches in on the A4000 side of the adapter, and extract the 5V err pin.
2) Use a pin to push the little metal latches in on the ATX side of the adapter and extract the 5V ... pin that goes into the ATX cable from the power supply
3) Crimp a new A4000 side pin onto a pair of copper wires and on the other end, insert them back into the ATX adapter which goes to two different ATX 5V pins on the ATX connector which goes to the ATX power supply.

The reason I asked if the case was open or not, the original A4000 power supply was designed for the only exhaust and airflow in the system. If you don't have a closed system the heat is just radiating into the air and parts around it, even though it's open this is not how the system was designed to operate. And I don't know how hot it is in the room, or any kind of airflow. Which is why I said just in case, point a big fan at the system.

As far as other places to "inject" 5V power into the system, sure you could just pick any old place on the motherboard (that has thick traces and is connected to 5V supply) to solder a 5V onto, which you would plug into any of the extra free 5V pins on the ATX cable. Some folks like Wrangler made a "5V Injector" out of veroboard and plugged that into a Zorro connector, for him the problem was getting enough 5V supply to the Zorro/PCI busboard.

What I do, is just buy the connectors and pins for the A4000 Motherboard connector, ATX female connector and make my own with copper wire (not the tin that Amigakit uses). Also get the gold plated connectors as the price isn't really much more and might oxidize less over time (?). Also since it's going on 25 years, replace the A4000 motherboard connector again with rich heavy yellow gold, or at the minimum clean the inside of those pins with alcohol or some "safe" electric cleaner, use a tool that can abrase the inside of those pins until they are not coated with a layer of gunk.

The Amigakit ATX adapter is probably ok or just fine for A4000D Tower conversions, as those Mediator busboards have the P9 connector to get a little more 5V supply onto the busboard/motherboard.

Specs for reference just because, maybe gives a little perspective:
A4000D
Warpengine 060/66MHz will run 80MHz, but I don't really need the speed.
Mediator
Ragnarok PPC @ 800MHz
Voodoo 3-3000
SB128+LAN
256GB SSD (used to have 10K 300GB SCSI drive but I didn't want the noise)
Optical Drive
CF Reader
Ratte Switch
64MB motherboard mod
PSU is a Corsair SF450 SFX
+Fan in busboard area
+Voodoo exhaust fan at the Expansion slot between the Zorro slots and the PSU

28 August 2019, 04:00	#8
grelbfarlk Registered User Join Date: Dec 2015 Location: USA Posts: 2,944	Well not many people run really fully loaded A4000s any more. There are a few of us, sure, but how many times do you see a post about power supplies with say, A4000D with a fully loaded Toaster System, including say, a pair of 10,000 RPM drives? They'd probably have the same problem with the Amigakit adapter. It's like this, here's what I did with one of the Amigakit adapters: 1) Use a pin to push the little metal latches in on the A4000 side of the adapter, and extract the 5V err pin. 2) Use a pin to push the little metal latches in on the ATX side of the adapter and extract the 5V ... pin that goes into the ATX cable from the power supply 3) Crimp a new A4000 side pin onto a pair of copper wires and on the other end, insert them back into the ATX adapter which goes to two different ATX 5V pins on the ATX connector which goes to the ATX power supply. The reason I asked if the case was open or not, the original A4000 power supply was designed for the only exhaust and airflow in the system. If you don't have a closed system the heat is just radiating into the air and parts around it, even though it's open this is not how the system was designed to operate. And I don't know how hot it is in the room, or any kind of airflow. Which is why I said just in case, point a big fan at the system. As far as other places to "inject" 5V power into the system, sure you could just pick any old place on the motherboard (that has thick traces and is connected to 5V supply) to solder a 5V onto, which you would plug into any of the extra free 5V pins on the ATX cable. Some folks like Wrangler made a "5V Injector" out of veroboard and plugged that into a Zorro connector, for him the problem was getting enough 5V supply to the Zorro/PCI busboard. What I do, is just buy the connectors and pins for the A4000 Motherboard connector, ATX female connector and make my own with copper wire (not the tin that Amigakit uses). Also get the gold plated connectors as the price isn't really much more and might oxidize less over time (?). Also since it's going on 25 years, replace the A4000 motherboard connector again with rich heavy yellow gold, or at the minimum clean the inside of those pins with alcohol or some "safe" electric cleaner, use a tool that can abrase the inside of those pins until they are not coated with a layer of gunk. The Amigakit ATX adapter is probably ok or just fine for A4000D Tower conversions, as those Mediator busboards have the P9 connector to get a little more 5V supply onto the busboard/motherboard. Specs for reference just because, maybe gives a little perspective: A4000D Warpengine 060/66MHz will run 80MHz, but I don't really need the speed. Mediator Ragnarok PPC @ 800MHz Voodoo 3-3000 SB128+LAN 256GB SSD (used to have 10K 300GB SCSI drive but I didn't want the noise) Optical Drive CF Reader Ratte Switch 64MB motherboard mod PSU is a Corsair SF450 SFX +Fan in busboard area +Voodoo exhaust fan at the Expansion slot between the Zorro slots and the PSU Last edited by grelbfarlk; 28 August 2019 at 04:29.