Z600 gives 4 beeps at startup, but only sometimes

[Tiresias77]

I have an aging Z600 workstation that has been souped-up in a few ways (24 GB RAM, SSD, etc.). Unfortunately I did most of those upgrades at once, so when the machine started giving the 4-beeps (bad power supply) and failing to startup, I'm not sure which component to suspect. And the problem is intermittent--if I remove the power supply (and unplug it from the graphics card) and then re-install it, the machine starts up and runs just fine.

Does anyone have a hunch on which component could cause an intermittent 4-beep situation? Thanks so much!

[DGroves]

do a power supply "BIST" test which is covered in the user and service manuals and if ok,

then i would first try replacing the video card with a cheap 10/15 dollar one and if no issues

then replace the video card with your preferred one, if this new card uses the AUX pwr and again causes issues then the problem is  most likely isolated to the power supply specifically the "aux gpu" power supply section

[Tiresias77]

Thank you DGroves. With the power supply completely removed from the machine, its fans do spin up and the BIST LED illuminates (but does not illuminate with it installed and the 4-beep condition occurs). I'll try to round up another video card and do what you suggest. It seems like you suspect one portion of the power supply may be bad, despite the good BIST test?

Additional info: When the 4-beep condition occurs, the machine makes no other sound--no fans even start to spin up. And it will enter the same condition consistently when trying to come back from sleep/power-save mode as well.

[Tiresias77]

Okay I've got some more clues here. Short version: I've determined the machine will not start up with a monitor connected to the DisplayPort connector of the graphics card.

I tried completely removing the graphics card (Sapphire Radeon R9 270X Dual-X Edition) and the machine got through POST (but then of course failed with the 6-beep code). I reinstalled the graphics card; no 4-beep code. I connected one monitor to the DVI port: boots fine. I connected a monitor to the DisplayPort port: 4-beep failure. The DisplayPort cable can be connected and works fine after boot is complete, but if it's connected at power-on I get the 4-beep failure.

Funny thing is that I thought removing and reinstalling the power supply was getting me the occasional good startups, but really it was that I needed to unplug the DisplayPort to lay the case down sideways. 🤣 Oops--not my best troubelshooting.

The way the previous owner had this thing set up: The graphics card has two 6-pin aux power connectors, and apparently will not work without power supplied to both connectors. The HP power supply has the single 6-pin aux connector. So they got the power for the other 6-pin connector by using an adapter and pulling power form the end of the (not sure about the terminology here) wiring harness that powers the optical drive. It's only the optical drive and the graphics card on that chain of wiring, but maybe that's not supplying enough power to the graphics card somehow? Would it be better to power the graphics card another way?

[DGroves]

actually i suspect the video card

the z600 only came with a 650 watt power supply as i recall (SDH am i correct here?)

what is the make/model of the video card? i suspect that the video card is pulling more than the power supply can reliably supply due to ageing of the system and or add-in cards

it is possible to replace the HP specific power supply with a industry standard "ATX" power supply using a adapter

https://www.amazon.com/Eyeboot-18-Pin-Supply-Adapter-Motherboards/dp/B01HQ2JQ3G#feature-bullets-btf

then  use a name brand 750/850 watt power supply skipping the no name Chinese 800 watt supply for only 29.00

Delta/Corsair/Cooler-Master are just a few quality makers/resellers of good power supplies

or buy a newer video card that uses less than 150 watts if using the HP pwr supply

[SDH]

Yes, only one. It is 650W rated, and quite proprietary in size and shape. It slides into the very bottom of the case, is long and low, has a meshing attachment into the rear of the odd shaped power supply "bay". Kind of like a magnified BlindMate electrical connecting system. Major project due to lack of spare space inside the case... I think a non-HP one would have to be outside the case... a ghetto mod for sure. Certainly not worth the effort.

Video cards keep getting better, faster, and use lower power for same or better performance as time goes forward.

[SDH]

To OP:

You and the original owner did not know that the HP power supplies are built to higher-than-ATX standards and capabilities. The 6-wire PCIe supplemental power cable is rated to 18A of 12VDC current with the ability to supply a max of 216W of power to a video card. HP makes a very high quality splitter that takes the cable's output from its black plug end and splits that out to two 6-pin plugs. The advice is to get one of those or near equivalent quality rather than a no-name cheap low quality one given the amperage. This has been posted about many times in the forum here, even providing the HP part numbers for that special quality splitter and some less expensive quality alternatives.

https://www.techpowerup.com/gpu-specs/radeon-r9-270x.c2466 is a link to the GPU specs archive they keep... your card has a 180W max TDP so your single cable with a quality splitter can handle that with no problem (even if zero power came up via the slot it is plugged into, which is not the case). Though yours is a two-slot-wide card it has only 1 PCIe x16 connector along its bottom and gets up to 75W from the video card slot it is plugged into on the Z600 motherboard. It appears the one supplemental power cable from your power supply should be able to serve that card without issue. I'd use what HP engineered in.

Z600 power supply 650W max

High wattage PCIe supplemental power cable

[Tiresias77]

I was wondering if a 6-pin power splitter would work and possibly solve the graphics card problem. I think I found the part number for the HP splitter here: https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/HP-Z840-with-850W-... and the part number 721858-001. I'll try that, and then move on to replacing with a lower-power-consuming graphics card if that does not work. Also I have a viable workaround in the meantime: just start the machine with the DisplayPort cable unplugged, and don't let it go to sleep. Thanks so much for all the input and advice, folks!

[Tiresias77 · Accepted solution]

Alright folks, I just had to post this follow up because the solution was so weird (and somewhat embarrassing!)

I tried the high-grade HP-branded 6-pin power splitter for the two 6-pin connectors on the video card. It is indeed a high-quality connector and built like a tank, but it did not solve my problem (it does seem more elegant/correct than powering the 2nd connector off the drive power wiring, and I'm glad I installed it).

Then on a whim, I tried a different (brand new) DisplayPort cable, between the same monitor as before and the same graphics card port. Problem solved. I've rebooted multiple times now with no issues. I have no idea how a faulty DP cable caused the machine to not start up, but that seems to have been the real issue.