Z840 Startup Problems - Single White Flash. No Beeps

[DGroves]

i cannot stress this enough,..... you must use RETAIL cpu's

eval units will not work or will not work reliably

your 2699 cpu's must be "SR2JS" any other code indicates it is a non retail ES/QL cpu

[pavel210]

They are both SR2JS:

[DGroves]

since your system boots with the v3 cpu but not the v4 2699(s) a last test is to buy one (or two) v4 cpu's from a reseller that is willing to take returns.

if you go this route please make clear to the seller before buying that your existing v4 cpu's will not work  but that a v3 cpu does and that if the v4 cpu's from him fail, it's not the cpu's but your system that is at fault and the returned cpu's are most likely fine and offer to pay for the return dhipping even if the seller said he will cover return shipping

https://www.compeve.com/Documents/HP%20Z840/hp_Z840_quickspecs_compeve.pdf

[SDH]

Grasping at straws now...

Small size memory is cheaper/GB than more desirable larger size sticks. I'd cough up about 20.00 for 2 or 4 4GB sticks and see if it was a memory problem all along (despite being able to boot from that v3 processor with that one 32GB LR stick you show). Note that in the Z840 QuickSpecs DGroves provided a link to there are single processor and double processors charts on where to put 2 or 4 sticks, and those even rank the resulting memory performance.

I agree with you and DGroves that at least one those processors should work in that workstation... hard to believe you got 2 duds. I've gotten a few over the years, but never 2 at the same time. I've never seen a case where HP-approved v4 processors could not work in our dual processor Z640 workstations and same with our single processor Z440 ones that came with v3 processors. We don't have any Z840s.

EDIT: LR memory also was approved by HP but to my knowledge you could not mix it with non-LR memory. Personally I never use those... seen issues over the years. Here's an easy way to get some inexpensive recycled eBay non-LR ECC buffered HP sticks that can run at the fastest (2400MHz) those workstations can ever accomplish with v4 processor(s): Look up 854912-001 (which will get you more than one HP OEM source, mostly Samsung) or look up M378A5244CB0-CRC (Samsung only). I'd pick Samsung and make sure the HP bar code label is present on the right side of each stick.  Supposedly HP bins their OEM memory to higher-than-minimum specs before their sticker goes on (but I've bought it both ways without issues). Message the seller the HP sticker has to be present as you pay.

Later on, HP also sold 2666MHz non-LR memory for the Zx40 workstations because it actually became cheaper to source than the 2400 version. The memory controller will downrate it to 2400 automatically. For example, check eBay for 933274-001. As above you want to match ECC buffered, rank, speed and OEM source plus the HP sticker being present. For those I'd also search via Samsung M378A5244CB0-CTD and look for the HP sticker.

[pavel210]

Thanks for the ideas.

I have ordered a 2640v4 (its ~20USD from another seller) and will report if it works.

I don't think its a memory issue because if I remove RAM all together, so all DIMM slots are empty, with the 2630v3, the fans spin up and I see the predicted red LED. With the 2699 everything halts right away.

In your experience, could it be a PSU issue? For example, could the PSU be "on its last leg" - it powers the 2630v3 but then doesn't have enough juice for the 145W 2699v4? If so, the PSU seems to be harder to come by.

[SDH]

Good to try another v4 processor. Never have seen another case where a single (or 2) higher power processor stressed a power supply to the degree that this happened. DGroves has much more experience with the 8 series than we do.

I was swinging for an inexpensive home run with that memory idea (which I'd still do here because I have spares in my stash).

[DGroves]

as unlikely as it sounds i suspect the original 2699 cpu's to be the cause of the no boot issue which is why i recomended a replacement test v4 cpu

no, the HP power supply is not at fault here your no boot issue with the original 2599 cpu's is not power supply related

[pavel210]

Thanks for the reassurances on the PSU.

Both of my 2699 chips were form the same seller. So I do wonder if that could be the problem.

I will see how the one I ordered goes and if that works, then it might be worth getting another 269X series form a different seller.

[pavel210]

The 2640v4 arrived, and..... it booted!

So it sounds like your theory of multiple bad 2699s is the more likely version at this point. I will see if I can source another 2699 or similar from a different seller to confirm.

Incidentally, just curious if the machine supports running with two different processors? Assuming they both support same memory and QPI, can I run, say a 2699v4 + a 2667v4?

[SDH]

We wish you could but you surely can't. DGroves looks like he got the home run!