Lenovo Ideapad S145-15IIL RAM problem

[FZG]

I have a strange problem with an Ideapad S145-15IIL (nm-c711). This computer has 4 GB of RAM soldered to the board and works absolutely fine as long as the additional SODIMM slot is not populated. When additional RAM is inserted then sooner or later the machine will freeze and show glitches on the screen. Mostly happens in Windows but can also happen in BIOS and also happens when booting a live Linux. Most times it happens straight upon booting the OS but sometimes it works for some minutes before it crashes.

I tried different sticks of RAM, checked the slot and its connections, flashed the BIOS... but nothing helped.

What I find strange is that I never get bluescreens, it´s always graphic glitching that looks like VRAM errors. The laptop does not have a discrete GPU, it is integrated in the CPU (i5-1035G1).

Any ideas for possible causes and things I could try to fix it?

[FZG]

Nobody?

[mcplslg123]

Since there is no issues with onboard ram and issue arises only with ram slot,very likely the slot itself is defective(cpu memory controller should be ok as its working with onboard ram). The best idea is to use a ram slot tester.

[FZG]

RAM slot looks okay though. No corrosion, nothing bent. I checked every single pin is soldered solid. I´m not ruling out the CPU yet, maybe a cracked solder ball corresponding to DDR channel A (the slot).

Another thing that seems strange but might be normal: I checked resistance to ground and voltages on all coils. CPU coils (PL3400, PL3401) read 128 Ohm and voltage can be up to 1,6 V. Both values seem quite high to me. But I don´t know unless someone with the same board can confirm this.

[Stevedb]

Is it soldered memory with those black glue. Does it has slot also pressure on the ramstick while starting board does it help?

[FZG]

Yes, the onboard RAM is stuck down with black glue. Putting pressure on the RAM stick or rattling it never really changed anything.

I have now resorted to re-soldering every pin of the RAM slot (to eliminiate possible cold solder joints) and the machine is now running for over an hour without the issue appearing. But I am still very hesitant to call it a fix. Will need to leave it running for some time and run some tests.

Still don´t understand (if it was bad connections) why it never resulted in bluescreen errors but always graphical glitches. Is that expected behaviour?

[FZG]

Ran fine for a few hours, then the problem reappeared. It is a very intermittent fault.

[mcplslg123]

A ram slot tester comes handy in this type of scenario. The ram slot is very shoddy in HP's but cant rule out any other brand.You know the quality of the mb's these days are awful.To mee it still seems like an issue with ram slot itself.

[Stevedb]

With onboard ram only it works perfect then?

[FZG]

Yes, no problems at all with onboard RAM only.

About the RAM slot tester: how do they work? Would like to know more. If they check the connection between the slot and the CPU, then what would that tell me? A missing or weak signal could still be caused by the slot or the CPU.

[Stevedb]

Clean the boards. Check the ddr slot for lose pins or dirty pins

[FZG]

Already cleaned it and resoldered the pins. Laptop is in a stable phase right now but I fully expect it to fail again. But thanks for the input.

[mcplslg123]

Cpu is very unlikely at fault since it works fine with both onboard ram and slot,hence the doubt towards ram slot. Slot tester will confirm whether the slot is bad or not.Yes i agree no tester can guarantee 100% but it gives you a close idea about the fault.

[FZG]

Laptop has just passed two complete runs of Memtest86 without errors so I might call it fixed for now, even though I have changed nothing since the last time the fault occured. Strange one. Thanks for your help, guys!

[tomodachi]

Same exact issue happened to me with few units.
I do believe DIMM slot is failing due to poor soldering from CPU side. I strongly believe a proper reballing would solve this issue.

[FZG]

I do believe the same but CPU reballing is out of my league and the laptop is running fine at the moment.

[tomodachi]

" if it works, don't touch it " is my motto when it comes to Lenovo lol

[FZG]

Exactly 😅

[hakusembons1993]

Is it soldered memory with those black glue. Does it has slot also pressure on the ramstick while starting board does it help?

Hi, i have an issue with the soldered module (NM-C711), if the ram module has touched, appears artefacts on the display, so, if i installed any stick on the SO-DIMM module, the laptop power on but doesn´t have image.

Sorry for my bad english.

[mcplslg123]

You need to disable onboard memory and then try with a ram stick in slot.