Problem with Lenovo P50 laptop's RAM
Problem with Lenovo P50 laptop's RAM
I possess a Lenovo P50 i7-6700hq with expandable capacity up to 64GB using four SSDs. Upon receiving the laptop, it came with two 8GB 2133MHz Samsung DDR4 modules. I purchased two additional 8GB 2666 modules and installed them, but the device failed to boot. Here’s what I’ve tried so far to diagnose: 1) I installed only one module instead of two, and it started working. I assumed a defective stick was the cause, but swapping them didn’t fix the issue. 2) I suspected a faulty socket, so I changed the slot where the single module was placed. Still, the machine booted. 3) After removing the Samsung memory and replacing both modules with two new ones, it booted after one addition, then failed when a third module was inserted. It only worked with up to three modules. I also experimented with a 4GB Samsung 2133MHz stick and a 16GB Crucial 2400MHz module, but the same problem persisted. I’m unsure what to do next—consider updating the BIOS to check for possible fixes. Any suggestions would be greatly appreciated. EDIT: BIOS update didn’t resolve the problem. Updated December 5, 2022 by Arethusa update
You're trying to adjust the RAM voltage but might not have enough power for all four slots. Consider using Samsung memory and sending it back via RMA. Check if your BIOS allows changing the voltage or what the current specs are for each RAM stick. When three slots are filled, what are the voltage requirements for each RAM?
Thanks for the update. I'm proceeding with the RMA process and agree to use standard RAM. It seems there might be an issue with the dimmer settings and timing. Here are the voltage requirements: KLLISRE: 1.2v Samsung: CPU-Z displays the same voltage as the specifications. I also considered the possibility of mixing ECC and non-ECC, but that hasn't been confirmed yet.
In case someone looks into this thread later, I managed to get it working by setting the dims in a series or matching channels. There are two RAM slots beneath the keyboard and two on the bottom of the laptop. If you're using separate dims, the top slot under the keyboard must match the type of memory on the underside. I believed I had already checked that setup, but after another attempt it functioned! All four dims settled at 2133mhz, which is the CPU's maximum support.