New HP memory modules are rejected by my HP Z440 workstation.

[WalkCycle]

Hi there.

I wonder if anyone can help. I ordered and received today two HP 8 gig memory modules from the United Kingdom HP Online Store. These are for for my HP 2440 Workstation.

The memory modules are being totally rejected now. I’m getting the red flashing light, loud beeps and no boot up.

I took them out and machine is fine again now.

I thought I had checked for compatibility.  I’m worried now I didn’t look closely enough and have screwed up.
Does anybody know for sure I bought incompatible memory ? Or what options there might be now ? Could I partly trade them in somehow for the correct memory ?

So this is the memory product description I have in the emails.  There are eight memory slots in two sets of Four. There are two existing eight gig memory modules in slots One and  Two.  I installed the new Eight gig memory modules in slots Three and Four.  Possibly this order was wrong ?  Clasping at straws now,  I know.

Item ...0100 Description ... HP 8GB DIMM DDR4 Memory Product ... P1N52AA
quantity ... 2

If anyone can help. Thank you so much, and all the best. If this isn't enough to go on I'll try to find out more.

[Red5_1]

https://support.hp.com/us-en/product/hp-z440-workstation/6978828/document/c04506309#AbT2

One of the important requirements for this PC is that the memory must be registered.

It took some time to track down whether PN#P1N52AA is registered or unregistered memory or not. Practically all of the listings omited 'registerd' and 'unregistered' from the product descriptions. Finally I came across PN#P1N52AA listed on NewEgg and their spec section confirmed it is indeed unregistered.

I did come across this document for your workstation that suggests compatible kists on Page 12. You probably want PN#J9P82AA.