Lenovo Ideapad 3 wont post when additional ram is inserted

[kulokutoys]

I have an Lenovo IP 3 that doesn't post when open ram bank is seated. I already tried many rams and different frequency's and update the latest bios still doesnt post when ram is put on the empty bank. working when onboard alone but onboard is only 4gb. any ideas or solution would be helpful.

[Sephir0th]

Re: Lenovo Ideapad 3 wont post when additional ram is inserted

Look for cold solder joints at the slot and broken slot pins. Same manufacturer boards have this kind od design fault.

[kulokutoys]

Re: Lenovo Ideapad 3 wont post when additional ram is inserted

did some reflow on all the pins.

[silvake]

I encountered the exactly same symptom on another IdeaPad 3 with 10th gen i7 CPU.
Onboard RAM working fine as expected, passed any tests I put it through.

As soon as I add another SO-DIMM in the extra slot, the board doesn't POST, no matter what module I use, e.g. 4g, 8g,16g, different frequencies and various brands, same result.

Under the microscope I checked the SO-DIMM pads for any possible cold or cracked joints, but found no evidence of such problem. Nevertheless, I resoldered all the SO-DIMM pins, just in case, but no change afterwards either...

At this point, I tend to suspect a failure of the CPU or some soldered memory chips (those infamous black-glued cips Lenovo is using on those IdeaPad models), but I simply can't ignore the laptop in working fine with the CPU and the onboard RAM...

kulokutoys, did you find a solution?
Sephir0th, any other ideas?

[tomodachi]

Reball the CPU