My Lenovo Thinkpad T420s laptop boots only about 10% of the time
I bought this laptop as per description, I bought it refurbished since I wanted a cheap and light laptop to carry around, I just love it.
The laptop worked flawlessly for 8-9 month then suddenly it started to have problems.
At the beginning it started to freeze when using it (screen freezes or BSOD and that's it), I had to power it off with the power button and then restart it.
After 2-3 months of this it started to refuse booting, sometimes it boot, sometimes it doesn't; all the LED are on (power and HD) but the screen is off, it doesn't even show the BIOS screen.
The laptop boots about 10% of the times I try to start it, the other 90% nothing but the LED as described above, sometimes it freezes during use (very rarely) or it freezes at the LENOVO initial splaschscreen, but again all of this is completely random, I have no idea why it happens.
What I know is this:
- I'm pretty sure it's not the LCD panel, I tried to connect an external monitor but it's the same erratic behavior all over again
- I'm pretty sure it's not the HD since I tried with a new one, same story...
- According to he LENOVO user manual it can be one of these two things (in order of probability): 1 RAM Failure - 2 Motherboard failure.
Well, I hope it's the RAM of course (because it's 30 Euros and easy to change), if it's the MB I can pretty much kiss it goodbye because it would be cheaper to buy an other one than buying the MB.
I ran memtest but it seems ok, I disassembled the laptop completely to check for any loose connection but nothing I still get the same behavior.
Now I'm using it, when it boots it works pretty well (except for the very rare occasions when it freezes during use) but I'm puzzled by this completely erratic behavior.
Should I just buy a new RAM stick, do you have any suggestion?