Question RAM failing stress test

olip74

Distinguished
Dec 10, 2007
18
0
18,520
1
Hi, I'm upgrading the RAM in my neighbours laptop which is an Acer Aspire 5742, model PEW71. It came with 3GB RAM from Kingston, ACR256X64D3S1333C9 and ACR128X64D3S1333C9, which are 1.5V, PC3-10600.

I purchased 2 modules from eBay, both Kingston 99U5469-045.A00LF, which are 1.35V PC3L-12800. I understood that PC3L should be compatible with 1.5V and that the RAM should simply clock down to 1333MHz. BIOS registers the full 8GB but Memtest 86+ just crashes with both sticks installed or individually and the laptop obviously won't boot. This makes me think the likelihood is incompatibility rather than a fault with the memory.

Was there another factor I should have taken into consideration?
 

SteveRX4

Notable
BANNED
Sep 29, 2020
1,477
135
890
20
The ram itself could be faulty. It could be that it just won't work with your motherboard.
Most ram is only made up of kits of sticks that have exactly the same part number. Yours doesn't.
On a pre-built, such as you've got, you might not be able to find info on what ram has been tested for what CPU and found OK for your motherboard. Whereas I can find that easy on self built PCs by a quick google search of the motherboard.
 
Reactions: olip74

egda23

Prominent
Jun 14, 2020
669
120
640
20
Hi, I'm upgrading the RAM in my neighbours laptop which is an Acer Aspire 5742, model PEW71. It came with 3GB RAM from Kingston, ACR256X64D3S1333C9 and ACR128X64D3S1333C9, which are 1.5V, PC3-10600.

I purchased 2 modules from eBay, both Kingston 99U5469-045.A00LF, which are 1.35V PC3L-12800. I understood that PC3L should be compatible with 1.5V and that the RAM should simply clock down to 1333MHz. BIOS registers the full 8GB but Memtest 86+ just crashes with both sticks installed or individually and the laptop obviously won't boot. This makes me think the likelihood is incompatibility rather than a fault with the memory.

Was there another factor I should have taken into consideration?
What is your Bios version ?
Updates can be have here
https://www.acer.com/ac/en/GB/content/support-product/3277;-;AS5742
 
Reactions: olip74

olip74

Distinguished
Dec 10, 2007
18
0
18,520
1

olip74

Distinguished
Dec 10, 2007
18
0
18,520
1
Thanks. (y) I'm going to go for the same spec this time (PC3-10600) from a seller with a returns policy and not be clever. There's always a bit of hit and hope with these things, especially as you say, with pre-assembled HW.
Got some new RAM, works a treat. Also found another laptop to test the original RAM, which also works so I'm confident to resell on eBay. Thanks for the pointers all!
 

ASK THE COMMUNITY