04-25-2019 02:53 PM
Currently I am trying to upgrade memory modules on my ThinkPad P51 of type 20HH. It was planned to have maximum, i.e. 64 GB, instead of original 8 GB. After some research four of Crucial 16 GB DDR4-2400 SODIMM CT16G4SFD824A have been obtained.
With absolutely no problems two of them have been inserted in slots under the bottom cover. On that stage the laptop starts up and works perfectly with total 40 GB of RAM consisted of new 32 GB and original 8 GB. However, after adding a new memory module under the keyboard and/or replacing original 8 GB memory module with new 16 GB, and/or even putting original 8 GB memory module in the neighbouring slot, the laptop doesn't start up.
Several attempts have been done to solve this problem, i.e. BIOS has been updated to 1.47 version, CMOS battery has been removed and returned back to its place, SSD drive has been removed and returned back to its place, the laptop has been turned on with a battery only, with AC power adapter only and with both of them. Nothing of the listed above helped to solve a problem.
Did someone face the same problem? Is there a solution for it?
04-26-2019 07:13 PM
I would start with running memtest86 .
I have had this problem in the past . if there are no error's on module , then most likely mobo .
But not on any thinkpads the last 5-6 years .
Also another thing is try to get the modules under keyboard with recomended part nos.
Don't buy them from lenovo though . overpriced for no reason .
04-26-2019 08:48 PM
You may not be waiting long enough. After memory modules are changed, there are lots of tests run in order to configure slots as to memory speed, dual channel, etc. This is only the first boot. I have seen it take 2 full minutes or even longer. I turn it on and go make a cup of coffee.