PC doesn't boot after adding RAM

I have Lenovo M91P 7052-b5u i5-2400 (spec sheet) with 2+1 GB RAM

look like this .

Because I have 4 sockets, I decided to add 2 more.

Yesterday I added Kingston 4+2 GB RAM 99u5471, but the PC didn't boot. It was black screen - no POST.

I thought maybe the new RAM wasn't compatible - but after I took out the old 2+1 RAM, everything worked just fine.

So right now the PC boot only if I putting OR only the old RAM OR only the new RAM but not both of them.

What can cause this? Is it because the size is different? (the Kingston is smaller than the old ones)

(I already tried to switch between the sockets)

Thanks!

Dvir Naim

Posted 2017-01-22T09:26:47.530

Reputation: 1

My best guess is a difference in speed between different types of RAM chips. Getting the same make/model for all chips may fix this. (Yes, that might mean replacing some working equipment in order to get some more-compatible equipment.) – TOOGAM – 2020-01-21T12:41:30.447

Answers

Sometimes ram is required to be upgraded in pairs with the same size and spec. Use the Crucial Ram Scanner which will tell you what ram you need and if it needs to be upgraded in pairs or not

http://www.crucial.com/usa/en/systemscanner

Exhausted

Posted 2017-01-22T09:26:47.530

Reputation: 55

http://www.crucial.com/usa/en/compatible-upgrade-for/Lenovo/thinkcentre-m91p - can't see nothing about it... – Dvir Naim – 2017-01-22T10:07:43.783

Try resetting BIOS battery before adding new rams, then check new rams one by one to see which works. when you dealing with RAMs, sometimes PC doesn't boot, because it need BIOS reset. even if rams are working good. also different types of memories doesn't work together at some cases. they must be similar to work correctly...

George G.

Posted 2017-01-22T09:26:47.530

Reputation: 73

Tried.. didn't work... Why different types are causing trouble..? – Dvir Naim – 2017-01-22T10:20:34.773

Even if specs are same but because they are from different manufacturers that may cause compatibility problems... Some different RAMs works together, some not. I think that's the case – George G. – 2017-01-22T10:33:50.047

there is nothing to do ha..? Out of curiosity - does the size says something about the performance? – Dvir Naim – 2017-01-22T11:11:19.307