Z840 workstation will beep when power on

[xskan]

I have one Z840 workstation with 16G memory and I add another 16G memory (from another Z640 workstation with same type). Then when I press the Power button, it will beep 4 times continuously with red light on the power button. If I press the button again, it can boot up correctly. I re-installed the memory but the error still there. Even if I remove the extra 16G memory, the symptom still the same. What is the problem and how to fix it? Thanks! 

[DGroves]

either wrong type ram, mismatched ram, or improper dimm load order 

please follow the dimm load order that is attached to the z840 side cover,

note the dimm load order changes depending on if one or two cpu's

make sure all dimms match by checking the label on each dimm

ECC REGISTERED ram,.............. or non registered ram can be used (if less than 32GB)

ECC non registered ram can not be used, you cannot mix ram sizes within a memory bank, although each bank can be different (again check side panel for which sockets comprise each memory bank)

you cannot mix Load reduced ram and normal ram

[SDH]

I recall you also can't mix memory ranks either. It would be helpful if you posted here a good picture of your old and new memory so we can see the labels.

It is not clear to me if you have one 16GB stick and wanted to add another 16GB stick. Or, do you have four 4GB sticks and want to add 4 more?

[xskan]

Hi, thanks for your replying. Here is more details.

1. Only CPU0 used, no 2nd CPU.

2. All memory stick are 4GB each. Four of them from Z840 and the other four from another Z640 workstation. All memory sticks are original with both workstations. Unfortunately I cannot identify which four sticks from which workstation now...

3. Memory installed on CPU0 memory rank. CPU1 and its memory ranks are empty.

4. Each time when first press the Power button, there will be four beeps with red light. When I press again, it can power on and works fine.

5. Windows 10 Task Mgr can detect 32GB memory and 8 slots used.

6. Even when I only keep four memory sticks on this Z840, the four beeps will remain and only can power on upon press it again.

In short, everything works fine, except the four beeps upon the first press of the power button.

(I've tried to reset the BIOS but no use.)

Anything else I can try? Thanks!

[SDH]

I'm pretty compulsive on matching memory. Those 8 all have the same HP part number on the right-hand side HP label of each stick. Those are official HP numbers, and don't look printed by some scammer. All are rank-matched (the "1Rx8 designation) The far right 4-digit number on the left label has to do with date of production. 1605 means year ending with 16; week 5. I'll assume it is 2016, week 5 given the other documentation available.

The only odd one is that one made by SKHynix, rather than Samsung. It would be easy to get a Samsung stick to replace that. However, HP in the past has said that if you use the same exact HP part number you should be able to mix and match assuming it is truly an approved HP part number for the workstation. Yours all fit that, to the best of my knowledge. It is for sure at least perfect for the Z440 v2 workstations because I double checked that and have bought exactly that to get 8 matching sticks in place in the past for some of my Z440 souped-up projects that don't need more than 64GB quality RAM.

DGroves is highly experienced with the Z840. Me more so for the Z440/Z640. I'd follow his advice without hesitation. I'm stuck now other than suggesting you get one matching Samsung stick via eBay, price and shipping lowest filter and make sure it has that specific HP sticker on the right-hand side. A RAM stick can go bad, rarely, either HP-sourced or straight from OEM from another brand. HP still supposedly "bins" their RAM to above-OEM-vendor specs. You can find good deals by searching for the part numbers on the left-hand label and then only buying the HP ones once you see the right-hand HP label in the ad. Don't share that trick with anyone...

[DGroves]

the modules are correct and matched and approved for the z840 and yes HP can and does use different ram makers dimms with the same part number

these different modules have been tested and validated by HP to perform similarly when used together 

i would clean the dimm's contacts and also use a commercial contact cleaner on the dimm sockets

pay attention to the bios on boot, is it decreasing the found ram count downward from the expected value?

since the memory controller resides in the cpu(s) try swapping cpu's and note any changes it's remotely possible for a bent cpu socket pin or a bad cpu to cause this however the much more common problem is wrong dimm load order in sockets or bad dimms/dimm sockets

[xskan]

@DGroves, thanks for your advise and I did cleaned the DIMM connectors but the beeps remain the same...

In the BIOS, it can correctly detect the 32GB Memory. (After I reset to factory default, the next restart it reminds me to confirm the memory size changed.)

Also I did the memory test from the BIOS startup menu and it passed all.

Is there any other places I can check and try? Thanks again!

[xskan]

One more question. Is there any possible Power supply issue, or any related settings need to check? Cause the beep always four times which should be the power supply related issue?