HP ProBook 6440b upon upgrading ram to 8gb enters a bootloop

[AdamVarga]

HP 6440b Bootlooping after ram replacement. The original ELPIDA ramstick which is a 2gb stick works fine, however when I replace the ram stick it just enters a bootloop- by boot loop I mean I dont even get to see anything on the screen. It just shines the lights for a few seconds then shuts down. After this happens a few times it just locks up full fan speed and doing nothing - black screen with no backlight on.

Interestingly enough rapidly switching the ram sticks old stick and new stick sometimes I did get it to the bios and it would actually detect 8gb of RAM but when I try to boot it, it refuses to do so. No warning just the windows logo for a few very short seconds and it just goes black again and back to bootlooping.. 

Im not sure whats the deal here. It has a2010 bios which I ried to update to the lates 2015 version and it didnt update. Though me occasionally getting it to recognise the ram is there makes me think of a different idea than a bios problem. The ramstick Im working with is a Apacer 8GB DDR3L-1600, and its not faulty since it works on my lenovo. So not sure where to go about this further..

[Paul_Tikkanen]

Hi:

I suspect the problem is the notebook only supports 2 x 4 GB of memory and the slot can't support a single 8 GB chip.

See chapter 1 of the service manual.

570786m3.book (hp.com)

There is another issue with HP notebooks with the Intel 1st gen core processors and that is they use a very specific type of memory.

You can read this discussion...your notebook would use the same type memory as the 6550b.

Solved: Memory upgrade 6550b - HP Support Community - 5340551

[AdamVarga]

This explanation does sound likely. I wasnt the one buying the ram sticks so I only figured out after the fact. 

What is interesting that I can somehow force it into the bios with even two 8GB ramsticks in it and it would say total memory 16GB but if I try to run windows actually from it it would basically crash and not work at all after that. But it does detect it and knows its there..it seem just it cant handle it. The replacement memory is also DDR3L so dual voltage which in itself would suggest it could work but apparently no..

[AdamVarga]

I have tracked down the memory by its spare part number 599092-002 that a Apacer SO-DIMM 4GB DDR3 1600 MHz CL11 should do the trick (PC3-12800 CL11).

I will update this thread (hopefully) upon arrival of the memory. 

[Paul_Tikkanen]

The main thing is the clock speed.

DDR-1600 memory can't go back two speeds to 1066 MHz, which is one of the reasons I think there is a problem.

If the notebook has an Intel i7-720QM quad core processor, that should unofficially support 16 GB of memory.

The dual cores will not.