Any suggestions what else to try?
Any suggestion can be tested in the name of good experiment
This is what is it all about , to learn something

Thanks for reply!
The only thing I'm still thinking here is something wrong with the slot is because the LED are going on and off while massaging the slot while the tester is locked in it.
I tried press on the CPU it self and there is no change how the testing board is lit.
You said Lenovo used low melt solder, does this mean that the 370F temperature I used to bake it was sufficient to reflow the board?
Board is NM-C421
This is just a project, nothing crucial so I'm willing to try anything for good experiment ...

Thanks for your reply as well!
I just posted pics when you posted, yes, that epoxy is seen on the memory socket as well.
I pick the temperature from ideas while goggling on the subject.
Check all the pins and didn't find any cracked....

Well, I did check it and don't see any problems with the socket but it is virtually impossible to see the underside contacts in the socket.
I ordered new slot and will replace it just for the fun of it I think the most difficult thing will be the old socket removal since one the left and right side (about 10 pins each side)
there is blob of some kind of glue, probably epoxy.
Reball of the CPU is probably not worth it.


...

Thanks for reply!
The test module it self there isn't much to it, no active components on it and I did test the traces going to those LED's
Memory it self was tested and works fine.
What I find strange is how the LED blink moving the test module when it's locked in the memory slot
I also applied soldering paste around the CPU while it was baking.
What do you think about the time of the baking and temperature?
From experience how often do you se bad memory socket?


Thanks for your time! You are great!...

Hi folks!
I have some kind of memory problem on Lenovo laptop. I was initially able to install windows after several tries since the laptop did freeze in middle of those attempts.
Eventually I discovered that it was related to moving the laptop.
Later on it even stopped booting unless I pressed around the memory slot. (no keyboard LEDs only power button responds)
If I remove the RAM I get the beeps that RAM is missing. Inserting the RAM there is silence and it will not boot most of the time. No picture.

I removed the board got one of those memory slot testers...