Use ATX PSU With HP Motherboard That Uses Proprietary PSU (& Add a GPU)

Many newer HP Desktops come with a proprietary PSU. These PSU's are often low wattage leaving little room for system expansion. A higher wattage PSU can be purchased but they are usually overpriced & still quite limited.

A PSU upgrade will allow you to add a more powerful Graphics Card (GPU) to your system, some extra hard drives, or even just replace a broken one on the cheap.

Many of the HP desktops can be booted with a standard ATX PSU but it requires the ATX PSU's green wire to be always grounded, resulting in the PSU always running. This is fine for many, but can causes issues. Luckily we can fix this problem. Just follow this guide.

This guide will only work with HP PSU's that used 2 x 4 Pin(CPU style) connectors for power & a 7 pin connector for the motherboard. Does not matter how many of the 7 pins are used, will work for any configuration. (See Step #2 for help). This will not work with 6 pin connector HP power supplies

Compatible PSU Models:

1. D16-180P2A*
2. PA-3401-1
3. DPS-310AB
4. D19-180P-1A*
5. & many others

*= Personally Confirmed

There are a few ways to approach building the adapter. Many pieces can be substituted depending upon your personal needs.

Materials:

1: ATX PSU:

1. Can be ATX, TXF, Flex ATX, Pico PSU, etc. As long as follows ATX standard with a 20/24 pin connector.
2. Needs minimum 2 amps on 5v VSB rail. Should not be a problem on modern supplies.
3. Look for one with hefty 12v rail(s). The entire PC will be powered off 12v. If using a GPU this is extremely important.

2: Boost converter:

1. Needs to support 5v input & 12v output. A minimum of 2 amps output.
2. I used a MT3608. Xl6009 is another common choice

3: 4-Pin CPU Power extension cable:

1. Get one long enough to reach from the adapter board you are making to the 4_Pin_#1 connector.
2. Only the male end is needed. Any cable with a male 4 pin connector will work. Can even cut it off the original HP PSU.

4: 2 x relay modules:

1. 2 are needed. A development board with 2 stuck together will also work.
2. One needs to support a 5v trigger signal and have the option to be triggered via a LOW signal (Usually via jumper).
3. Other relay can be either 5 or 12v. 5v is preferred.
4. Most common relay modules are rated at 10 amps. 2 x 10 amp relays will provide the motherboard with 240 watts. That should be fine for most PC's as is greater then the OEM supply. I used a 30 amp relay.

5: ATX Female plug/board

1. Any type of female ATX plug(Same end as a motherboard).
2. I purchased one designed to run 2 ATX supplies in 1 PC. Search "Dual power Supply Sync Adapter".
3. An extension cable will also work.
4. Be cautious with ATX breakout boards as they do not always break out the PWR OK & 5v VSB lines.

6: 1000uf capacitor (or larger):

1. Value is not critical. I found 1000uf to be the minimum required for my PC.
2. More power hungry machines may require a bigger value. Adding a GPU may require a different value.
3. 16v minimum.

7: Some type of header/Dupont wires:

1. Dupont connectors or a servo wire will fit. You can also buy the correct header.
2. You also can cut the original one off the HP PSU (PWRCMD).
3. Need to connect a minimum of three wires to the PWRCMD connector on the HP motherboard

8. Scrap Wire:

1. I used 16 AWG for the 12v, ground, & boost input. Used 22awg for relay power & signals.
2. Thicker is better for the 12v PWR & Ground. Other lines are okay with a smaller gauge, just don't skimp.

9: Mounting Block & Screws

1. You are going to want to secure your adapter component down. I used a piece of wood. Use whatever you want, just make sure it is not conductive.
2. If your tech savvy print up a PCB :)

Tools:

1: Small Screwdrivers:

1. The relays have small screw blocks. A small Philips & flat headed screw driver is needed.

2: Wire Strippers/Scissors:

1. Someway to strip & cut the wire to length.

3: Solder Iron & Solder:

1. Needed if attaching wires to ATX board, boost converter, & capacitor. Wont hurt to solder connections.
2. Can be avoided if purchasing all components with screw blocks & some splicing.

4: Multimeter

1. Never hurts to check things before plugging into PC. Debugging too.

To make this tutorial easier, here is a breakdown of the terminology that will be used.

Adapter Board = The adapter made from this tutorial.

Connectors:

PWRCMD Connector = 7 pin connector on the motherboard. HP PSU Connects to it. Not all PSU's use all 7 pins. Some may only have 3 positions populated.

4_Pin_#1 = 4 Pin connector closest to the PWRCMD connector. Location varies depending on motherboard. Typically is closest to the PSU, HDD Power Header, & SATA Ports.

4_Pin_#2 = 4 Pin connector closest to the CPU. Sometimes is under a plastic fan shroud. Location varies depending on motherboard. Typically is closest to rear IO ports.

Wiring:

ATX:

PS_ON = Green wire on ATX PSU that turns on PSU when connected to ground.

PWR_OK = Grey wire on ATX PSU that tells PC the Power supply is started up and ready.

5V_VSB = Purple wire on ATX PSU. Supplies a constant 5v source to the PC even when powered off. Used to power on motherboards & supply power to USB ports when off.

HP Motherboard/PSU:

PWR_ON = Green wire on HP PSU that motherboard uses to power on. Is 3-3 - 4v when PC is off. 0v when PC is on.

PWR_ID = Grey wire on HP PSU that motherboard uses to ensure PSU is started & ready. Needed or will not boot.

FAN_TACH = White wire on HP PSU. Used by the motherboard to control the PSU fan in order to be used as a cooling fan. Not present on all systems. If present will need to be bridged to a fan TACH pin (see Step #6)

Electronics:

NO = Normally Open. Terminal that is not connected to output by default. Becomes connected when signal is applied.

NC = Normally Closed. Terminal that is connected to output by default. Becomes disconnected when signal is applied.

COM = Common. Terminal that either the NO or NC terminal gets connected to depending upon signal.

Active High: Triggers when a positive biased signal is received. Ex: 5v signal.

Active Low: Triggers when a negative biased signal is received. Ex: Ground. (5v disappears).

Relay #1 = Relay that connects the ATX PSU_ON with GROUND. Uses signal from HP motherboard.

Relay #2 = Relay that switches between 12v Boost Converter & ATX PSU 12v rail when HP motherboard is powered on.

The original HP PSU is always outputting 12v to the two 4 pin connectors. This is the equivalent of keeping the green & black lines on an ATX PSU always jumped.

4_Pin_#1 must always have a 12v source connected. The power on circuitry is connected to it.

When the power button is pushed the motherboard pulls pin #4 (PWR_ON) of PWRCMD connector LOW. Pin stays LOW until the PC is shut off or power is lost. It then returns to HIGH. Inverse of an ATX PSU.

Pin #3 (PWR_ID) of the PWRCMD connector the equivalent of ATX PWR_OK. If the line is never OK (High) the PC wont boot. This wire must be connected directly to the ATX PWR_OK wire.

The pins on the PWRCMD connector are:

#1 Ground (Black wire)

#2 PWR Meter (Purple wire)

#3 PWR_ID (Grey wire)

#4 PWR_ON (Green wire)

#5 Ground (Black wire)

#6 Fan_Tach (White wire)

#7 Fan_CMD (White & red striped wire)

Not every PSU uses all the pins. Some only use 3 (GND, PWR_ID, PWR_ON). I have not found any issue leaving PWR_METER & Fan_CMD disconnected.

How this project works:

2 relays are used. Relays are powered off the ATX 5v_VSB line.

Relay #1 connects the ATX PSU PWR_ON & ground wires to turn it on. This relay triggers on a signal from Pin #4 of the PWRCMD connector. This relay is configured to enable on LOW. (Flip the jumper)

Relay #2 has the COM terminal connected to the 12v pins of the 4_Pin_#1 connector on the motherboard. The NC terminal is connected to the boost converter output. The boost converter input is connected to the ATX 5v_VSB. The NO terminal of the relay is connected to the 12v line of the ATX PSU. The capacitor is connected in parallel with the NO terminal. The relay triggers on a signal from a 5v line on the ATX PSU(Not the standby).

The boost convert supplies constant 12v to the 4_Pin_#1 connector. When the power button is pressed; relay #1 is triggered; which switches on the ATX PSU. Once the PSU is on it triggers relay #2 which connects the ATX PSU's 12v lines to the motherboard, cutting off the boost converter. A small interrupt of power occurs, which is minimized by the capacitor.

Wiring is simple. Follow the images for guidance.

Diagrams are all the same concept. They are just tweaked for different relay types & power sources.

I made many revisions to my adapter throughout the process. Some images may be inconsistent due to changes/improvements.

If you chose to use a dual power supply adapter for the female ATX plug such as I did here is how I soldered it.

You can use different pins for the 5v, & Ground. The 12v does not need to be attached to here if using the other half of CPU connector. I did it due to ease.

You could also use an ATX extension cable or a Complete ATX Breakout Board. Those will not require any soldering. Just splice or use the screw terminals accordingly.

1. Make sure PSU is unplugged from AC Mains.

2. Plug the 4 or half the 8 pin(4+4) pin connector(Depending upon ATX PSU) into the 4_Pin_#2 connector.

3. Plug the 4 pin connector from the adapter board into the 4_Pin_#2 connector.

4. Connect the PWR_ON & PWR_ID from the adapter board into the corresponding pins on the PWRCMD connector. See step #2 for pin locations.

5. Connect the 24 pin ATX connector of the ATX PSU to the adapter board.

6. Attach any 6/8 pin connectors to GPU & any Sata/Molex connectors to HDD/SSD's.

7. Plug the PSU into the AC Mains

8. Hit the power button on the motherboard....

The relay's should click & the PC will power up! Success!!! If not see Step #7 Debugging.

On some HP PSU's the PSU fan is used as a system fan. Without this fan present the PC will error 90E on POST saying a PSU fan is not present. The PC will still boot but the error is annoying.

An easy way to tell if you need this fan modification is to see if you have a wire in position #6 (Fan_Tach) on the PWRCMD connector. If so you, will get a fan error. An Elitedesk 800 G3 is an example that needs this fan mod.

The PSU fan communicates with the motherboard via Pin #6 (Fan_Tach) on the PWRCMD connector. This pin is simply looking for a Tach signal from a fan. You have a few options:

1. Run a jumper wire from a different fan in the PCs Tach pin to the Fan_Tach pin. Any fan will do, even the CPU.

1. Rig up a fan in the PC. Tie into any 12v & Ground from the ATX PSU to power the fan. Connect the Tach pin to the Fan_Tach pin on the PWRCMD connector. Note: Fan will always run full speed.

1. Add a fan controller. Wire it up however. Just connect one of the Tach pins to the Fan_Tach pin of the PWRCMD connector.

1. Add a Tach controlled fan to the ATX PSU. Remove the original fan from the ATX PSU & swap in a new 3 or 4 pin fan. Run a wire outside for the Tach connection. Connect to the Fan_Tach pin on the PWRCMD connector

CAUTION: Be careful when opening an ATX PSU. Dangerous voltages are present & lethal.

Both 3 & 4 pin fans will work.. On a 4 pin fan the PWM pin will remain unused.

If your PC will not start up with the new adapter board there could be a few things wrong. Here are some common issues:

PC tries to boot but immediately powers down:

1. Make sure all wires are tightly connected and all connectors are fully seated.
2. Make sure the capacitor is connected in parallel with the 4_Pin_#1 connector.
3. Try a larger value capacitor.
4. Make sure the boost converter is set to 12v output. A lower voltage will cause no boot. If using a 12v relay it may not fully trigger on a lower voltage.
5. Try a larger gauge wire.

Relay keeps triggering/light flashes:

1. Double check all wiring.
2. Make sure you have the wires connected correctly & securely in the PWRCMD connector. Reversed or missing wires will cause this.

Red Light on HP Power Button:

1. Power supply is not providing enough power.
2. Boost converter can not supply enough current. Try a different one or a PSU with a larger 5v_VSB current.
3. Check all wiring and connections. A loose 4_Pin_#2 connector can cause this.
4. Make sure the ATX PSU has enough wattage on the 12v rail.
5. Try using a larger gauge wire for your adapter.

PSU Fan Running Full Blast:

1. Check to see if Fan_Tach pin on the PWRCMD connector is connected. Without it the fan will constantly run full speed.

Note:

Some ATX PSU's will not work properly without a load on the 5v rail. A motherboard typically loads this rail, but the adapter in this guide will not. A dummy load may be need on the 5v rail. A 10 ohm, 10 watt resistor or an incandescent automotive style light bulb may be used. A few old HDD's will also work.

Attached Videos demonstrate some common issues.

Motherboard & relay lights flashing, CPU fan spinning briefly:

1. Check if PWR_ID & PWR_ON connectors on PWRCMD connector are reversed.
2. Check if PWR_ID Wire is disconnected
3. Disconnect the capacitor.

1. Issue with the 12v boost converter current. Try the following:

1. Unplug the ATX PSU from mains
2. Disconnect the 12v output of the Boost Converter from the rest of the circuit
3. Plug back in ATX PSU to mains
4. Connect the 12v output of the boost converter to the rest of the circuit.

If it boots, I am currently working on figuring this issue out.

Motherboard & Relays Power On briefly but power off:

Capacitor Issue.

1. Try disconnecting the capacitor and trying to boot
2. Try a larger value capacitor.

Everything Worked fine until I added a GPU:

1. Try disconnecting the capacitor and trying to boot
2. Try a larger value capacitor.
3. Try a power ATX riser. (Uses Sata, Molex, or 6 Pin).

If it boots with the riser installed congrats. Seems a power issue. I am working on figuring out the issue.

Everything works fine until randomly powers off:

Power or heat issue

1. Make sure you have adequate cooling & airflow.
2. If you had to bypass the fan error (See Step #6) additional airflow in your case may be needed.
3. PSU is not enough wattage. The entire PC is powered off the 12v rail unlike a regular ATX motherboard. This requires a lot of current, especially if a GPU is installed. Try a larger PSU
4. Try moving any HDD/SSD to the ATX PSU connectors. The HP motherboard converts 12v to 5v for the SATA power connectors. By connecting the HDD/SSD's to the ATX PSU directly the load on the 12v rail is reduced.

Most issues I have found result from a lack of current on the 12v standby from the boost converter. This is due to the low current output on the 5v_VSB rail. Here is a way to eliminate that as a potential issue:

You will need:

1. Adapter board
2. 12v power supply of some sort. 2+ amps. Make sure is a regulated 12v. The OEM HP PSU will work.

1. Unplug the ATX PSU from the mains power.
2. Disconnect the boost converter from the circuit.
3. Connect the Ground of the 12v power supply to the ground of your adapter.
4. Connect the 12v positive of the 12v power supply to where the output of the boost converter should be connected.
5. Plug in the ATX PSU & the 12v Power supply.
6. Press the power button on the motherboard

If it boots it means the issue is related to the 5V_VSB & boost converter. if not, continue through the debugging.

If using the OEM HP PSU, the yellow wires are 12v, the black Ground.

To boot the HP Motherboard from an ATX PSU without the adapter board:

1. Plug in the 4 pin CPU connector to 4_Pin_#2 .
2. Connect 12v & GND lines from the ATX PSU to the 4_Pin_#1 connector
3. ATX PSU will always be on. Needs to be unplugged to power off. HP motherboard should work as intended.

Extra Info:

1. The 12v lines used to power the motherboard can be taken from anywhere on the ATX PSU. I used the ATX connector but you can use any Sata, Molex, 6 or 8 pin . An idea is to split the CPU 8 pin (4 + 4) plugging one side into the CPU 4 pin connector & the other into your adapter board. If you purchase a 4 pin CPU power extension cable you can cut it in half & have all the connectors you need.

1. I designed my adapter board to fit in the 2.5" HDD bay & mounts using the original holes. You can put yours wherever.

1. The Molex & Sata wires from the new PSU can be used to add additional drives to the motherboard eliminating the need for HP's proprietary cable.

Some Ideas:

1. Make a custom PCB to minimize the mess.

1. Try it with MOSFETS or transistors. Definitely a better idea then relays.

1. Try to fit it all inside your ATX PSU or the ATX guts & adapter in the original HP PSU shell.

1. Make an enclosure for the adapter board.

1. Power 12V standby rail off original HP PSU or USB-C adapter. Usefully if Boost converter isn't cutting it.

1. A dual relay board would be smaller & neater. Requires less wiring & room.

A PicoPSU can be used instead of the ATX PSU & boost converter. Make the adapter according to this guide except instead of a boost converter; connect the 12v input from the PicoPSU to where the boost converter output would go. This allows you to avoid any case modifications. Great for GPU-less setups.

The OEM HP PSU's make a great 12v source. They have decent amperage and built quality. They can be used on a regular ATX/MATX motherboard with the help of a PicoPSU. Just use the HP PSU as the 12v input on the Pico.

Modify it however you want! Hopefully my explanation & diagrams will provide a solid understanding of how it works.

Many images were taken by me. Those that were not are from the following sources:

ATX PSU:

https://www.computeralliance.com.au/power-supplies

HP White Desktop:

https://www.hp.com/us-en/shop/pdp/hp-pavilion-desktop-tp01-3025t-bundle-pc

HP Elitedesk:

https://www.amazon.com/HP-EliteDesk-800-G3-DVD-Writer/dp/B01N27S6NF

Dupont Wires:

https://www.rexqualis.com/product/120pcs-multicolored-dupont-wire-40pin-male-to-female-40pin-male-to-male-40pin-female-to-female-breadboard-jumper-wires-for-arduino-raspberry-pi-2-3/

Capacitor:

https://www.amazon.com/5pcs-1000uF-Electrolytic-Capacitors-11X18/dp/B07GCV44GM

Solder Iron:

https://www.temu.com/8pcs-digital-display-80w-electric-soldering-iron-kit-180-450-degree-adjustable-adjustable-temperature-button-for-electronic-diy-kits-with-5-tips-solder-wire-tip-cleaner-g-601099522270700.html

Screw Drivers:

https://i.ebayimg.com/images/g/x1QAAOSwGqtjxGly/s-l1200.jpg

Scrap Wire:

https://png.toolxox.com/pngi?p=wTioxo_wire-png-electrical-wire-clip-art-transparent-png/

MultiMeter

https://www.superiorelectric.us/superior-electric-t3000-digital-multimeter-ac-dc-volt-test-volt-ohm-meter-vom

Wire Strippers:

https://www.lowes.com/pd/IDEAL-Wire-Strippers/3370008

Pico PSU:

https://www.amazon.com/Mini-PicoPSU-150-XT-DC-DC-power-supply/dp/B0045WFZSQ

3 vs 4 pin fan diagram:

https://www.cgdirector.com/3-pin-vs-4-pin-pc-case-fans/

PCB:

https://www.wevolver.com/article/trace-pcb-a-comprehensive-guide

ATX Breakout Board:

https://www.ebay.com/itm/224599257814

ATX Extension Cable:

https://www.amazon.com/StarTech-8-Inch-Power-Extension-ATX24POWEXT/dp/B000FL60AI

HP 7 Pin plug:

https://superuser.com/questions/1713585/how-did-hp-made-their-power-on-bottom-work-with-no-vsb-standby-on-their-pro-29

HP 3 Pin Plug:

https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/Power-Supply-Upgrade-for-an-HP-590-P0033W/td-p/6987299

Circuit schematic was created in: Fritzing.

The original design & circuit layout is 100% original to myself. Pinouts & functionality was discovered by disassembly & probing of the original HP components. No 3rd party was involved.

Hope this has helped out!

Feel free to comment with any questions/suggestions. Will do my best to answer & help out!

Also if you know models of HP PSU's this works with please comment them so I can add to list.