Replace HP EliteDesk 705 M1 MT Power Supply

[Luna27500]

Hello everyone,

I would like to replace the power supply of my HP EliteDesk 705 G1 MT because I would like to add a graphics card but the basic power supply does not have connectors for the graphics card. Do you know of a power supply that would fit in the case?
Good day to you !

[NonSequitur777]

@Luna27500,

Unfortunately, your OEM HP 280 watt PSU (HP p/n: 758652-001) is, as you found out, a proprietary HP power supply equipped with non-industry standard power connectors and no 6+2 / 8-pin PCIe power cable(s). Even with a compatible OEM HP 400 watt power supply, you still don't have sufficient juice and you still wouldn't have one or two PCIe 2+6 / 8-pin power connection cable(s) that just about any high performance graphics card requires.

There is, however, a very effective mod-fix to reliably power any high(er) end graphics card that would fit inside your desktop.  This can be accomplished through a synced, dedicated externally connected standard industry ATX power supply.

But be forewarned, it requires moderate to advanced mechanical/computer skills to make this happen.  If you are that guy, let me know if you are interested.  Be reminded: this is not a simple plug-in and play solution. And -DISCLAIMER: it would be a power modification that is not endorsed, approved or recommended by HP.

Kind Regards,

NonSequitur777

[Luna27500]

Hello @NonSequitur777 

Thank you very much for responding so quickly.
My EliteDesk 705 G1 MT tower has already been modified:
- The original processor which is an AMD A8-7600B has been replaced by an AMD A10 PRO-7850B because it was defective.
I wanted to put a card that would power up through the PCIe slot but the A10 despite its TDP of 95W consumes more than 185W when I use it intensively. Sometimes when I turn on my computer, I see under the HP boot logo written in red "PSU Overcharge" or something like that. I already have a graphics card on the PCIe slot but it's old (it's an ATI HD 5550).
Do you think that an ATX power supply would fit in the case and would be really compatible with the motherboard?

Have a good day !

[NonSequitur777 · Accepted solution]

@Luna27500,

Yes, you can power any graphics card with an externally placed, dedicated synced ATX power supply using a so-called ATX PSU ADAPTER ATX 24-Pin to SATA Power Supply Adapter -but more about that in a moment.  However, for this power mod to work, the expectation is that the original internal power supply is able to provide sufficient power for everything else: CPU, RAM, drives, etc...

So, the issue appears to be that the AMD A10 consumes so much power that your internal power supply struggles to meet demands. At least some of the time.  Your ATI HD 5550 only uses 39 watt max, that is almost negligible.

So, hypothetically, let's say you wanted to replace the ATI HD 5550 with a compact RTX 3060 graphics card.  Most of this graphics cards' power demand can be supplied by hooking it up to an externally synced ATX PSU with its PCIe 6+2 / 8-pin power connection cable(s).  However, the potential power draw of an RTX 3060 through your PCIe x16 graphics slot -and thus from your internally placed PSU, will most likely increase to up to 75 watts. That means, potentially, that your system will crash because it has now become internally catastrophically underpowered...

So, from my perspective, the external power supply mod for a high(er)-end graphics card will not work for you unless you upgrade your internal PSU also.  But that would make the entire upgrade project more complicated and definitely more expensive.  Anyway, I hope I haven't 'lost' you by now.

All this is certainly doable -I have spent some serious money to create these extreme upgraded legacy HP desktops for example -most powerful of their kind/HP model globally still: Solved: Upgrading HP Compaq Elite 8300 USDT - HP Support Community - 8118827 or this: Solved: Upgrading HP Compaq Pro 6300 SFF - HP Support Community - 8184303 or this: Solved: Upgrading HP EliteDesk 800 G3 SFF - HP Support Community - 8251218, but it is only worth-it, to be brutally honest, for dedicated and slightly eccentric computer nerds and geeks with too much time and money on their hands, plus being experienced mechanically/computer savvy.

If you want to read up what I have been talking about, please see this recent thread I contributed to.  -At least the intent was to contribute: https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/Gpu-upgrade-Only-180-watts/m-p/....

Hope this was helpful.

Kind Regards,

NonSequitur777

[Luna27500]

Thank you for responding.
I just tested a configuration on my PC:
- AMD A10 PRO-7850B
- 2x 8 + 2x 16Gb DDR3 2133MHz
- Nvidia GTX 1650 Super
- Samsung 860 EVO 2Tb
- Seagate Barracuda 8Tb
- A fan sufficient to cool the A10 (Be Quiet)
The Power button of my PC is red but when I put back my 4Gb DDR3 1600 it lights up but with the same error message during the boot and with the processor not exceeding 1.6GHz.

[NonSequitur777]

@Luna27500,

The Nvidia GTX 1650 Super is a very nice card. Try to run your rig with 2 x 8GB only -16GB is sufficient for almost all gaming, and without your Seagate 8GB Barracuda.

Kind Regards,

NonSequitur777

[Luna27500]

I use 100% of 32Gb of RAM...that's why I use more than 32Gb

[NonSequitur777]

@Luna27500,

Understood.  The problem, or so it appears, remains your low wattage internal power supply.  There is a possibility that your internal power supply is defective.  However, replacement 280 watt HP 758652-001 power supplies are expensive, and it may not be a fix anyway.

I'm going to do some more research to see if there are additional options.

Kind Regards,

NonSequitur777

[DGroves]

for those reading this thread keep in mind that the "MT" (micro tower) model/SFF model  use a ATX style power supply and the

EliteDesk 705 G1 DM Mini model uses a external power brick, they are not interchangeable

the HP 280/240 watt supply's appears to be the HP specific 6 pin power connector for on-off/fan speed  that also has the 4 pin CPU pwr and the 6 pin connector that supplies the motherboard with pwr and other voltages

this ATX adapter just might be compatible with your system,  (check with the vender)

https://www.moddiy.com/products/HP-EliteDesk-800-PSU-Main-Power-24-Pin-to-6-Pin-Adapter-Cable-30cm.h...

[Luna27500]

Hello, I replaced the original power supply with a modified power supply that I was given (550W) and now I can use my processor at full capacity. The power supply seemed to have a problem because the performance of my processor tripled and its consumption went from about 185W under load to 255W with this power supply. What surprises me is that the motherboard is supposed to support processors with a max TDP of 100W but according to AMD the base TDP is 65.2W so that's why it should work. I had to replace the fan because the processor was easily approaching the maximum operating temperature. I'm not surprised that an AMD processor heats up and consumes so much power because the base processor consumed 125W at full load and the FX 770K on this PC was 175W~.

Have a good day !