wont accept more than one sodimm but has two slots

[dicobalt]

I do most of my computing on enthusiast hardware so I am unfamiliar with the proprietary design choices of OEM hardware. I seem to have an unusual HP laptop but I'm not sure if something is broken or this is just how the laptop is. I just got two matching sticks of ram, 2x8GB 2400MHz 17-17-17-39 1.2V, xmp/docp is not necessary for these sticks. The board has two sodimm slots but it will only boot up with one stick of ram. I can put that ram into either slot and it boots, but if I plug in both sticks the laptop always refuses to boot. I only get a slight flashing of the display but no error message, lights, or beeps. Both sticks complete 4 passes of memtest86 without errors. I also disconnected the battery and discharged the caps to clear the BIOS but it still did not allow two sticks to boot. Upon taking out the old ram I noticed the words "one dimm only" silkscreened on the board. I bought this laptop thinking that I could use two sticks because it has two slots. Is this something that HP does with its laptops? Is this normal? It seems so bizarre and I can't imagine what the purpose of this configuration would be. Furthermore I noticed one of the screws holding the battery was slightly stripped. I'm wondering if this an open box item that is damaged? Does anyone have an idea of what's going on here?

[banhien]

@dicobalt 

The specs of your machine is

           https://support.hp.com/us-en/document/c07042414

It has AMD Athlon™ Silver 3050U (2.3 GHz base clock, up to 3.2 GHz max boost clock, 4 MB L3 cache, 2 cores) CPU/Processor therefore it should have 2 slots of RAM.

But it has words "one dimm only" silkscreened on the board there fore it only works with ONE slot, doesn't matter which one.

Regards.

[dicobalt]

This begs the question though, if it only supports one dimm why are there two dimm slots? It's just so weird man. You'd never see something like that on a desktop board. 

[dicobalt]

Looks like it does support two sodimms, I left the old stick in its original slot and one new stick in the second slot and it booted enough to boot and run CPUz but then it crashes because HP BIOS memory support tables don't support this ram. It may also be that the motherboard doesn't support two dual rank sticks of ram, I say this because the original 4gb stick is single rank. It would be nice if HP documented their hardware more thoroughly like any enthusiast motherboard would be. Even the Crucial memory website tool can't figure out what the heck is going on with this weird hardware. Anyway I found the service manual for this laptop and according to it I should be able to run at least 12GB (4+8), which is currently booting but then crashing under use. Page 10 of the pdf covers memory use: http://h10032.www1.hp.com/ctg/Manual/c06242992.pdf 

Unfortunately there is no mention of ranks  - but they do a good job giving replacement part numbers in an attempt to sell me stuff.

[dicobalt]

Well, to complicate matters even further it seems that the HP approved 8GB stick part number 820570-005 is impossible to search for on HP's own site because https://parts.hp.com is a blank webpage in all browsers except Internet Explorer 11. Seriously?! What the heck?! Then this website wants to sell me a mere 8GB at 2666 for $265!!!! https://parts.hp.com/hpparts/Search_Results.aspx?mscssid=7DDAF9ED91644160827826DCF969F0D4&SearchIn=P...

Other suppliers list the 8GB memory stick part 820570-005 running at 2133 rather than the 2400 that the service manual lists on page 10 http://h10032.www1.hp.com/ctg/Manual/c06242992.pdf but it's around the standard price of $42 per 8GB.

Meanwhile... HP's other part search tool (https://support.hp.com/us-en/products/accessories-parts) gives me totally irrelevant results when I search for 820570-005. 

If someone at HP is reading, all I have to say is, comon man... you need to hire me to get your stuff together.