T420 - rebooting in the middle of booting

[karlosss]

Hello!

I encountered a problem that not only my ThinkPad friends never seen before, but I also failed to find any clues using google.

I have a SSD with GRUB and dual boot Windows 7/ArchLinux. I was in the middle of working in Linux when my computer suddenly turned off immediately. When I tried to boot it back up, I never more managed to do so: after I hit enter in GRUB screen choosing Linux, I see "loading Linux" and "loading initial ramdisk", then everything freezes for about 5 seconds, and then the computer restarts. I noticed that the HDD LED never flashes during the boot attempt. When I try to boot into Windows instead, i can see the "starting Windows" screen for about 5 seconds and then the exact same restart happens. I also tried moving my SSD to UltraBay slot and also the same thing happened. Then I tried to boot a live Linux from a flash drive and the same thing happened again. And now I ran out of ideas.

To summarize: booting any OS from any kind of media plugged in to any suitable port of the computer results in the HDD LED not flashing and a restart after about 5 seconds since the start of the boot process.

I checked the startup options and it looks like T420 has nothing like diagnostics at the BIOS level. At least BIOS seems to work fine, though I have no idea how to make use of it. Also I probably have the command line of GRUB, which I never used before and I have no idea if it might be useful here somehow.

Any ideas are highly appreciated!

[atagunov]

Hi, I'd probably put Ubuntu distro on a USB and then attempt to use "Try Ubuntu" feature to see if the OS manages to boot from the USB stick. I suppose you could do a couple of runs: one with the SSD present and one with SSD absent. Could it be a dodgy SSD?..

[karlosss]

Hi, thanks a lot for the prompt reply! That is basically what I did, except I used Manjaro instead of Ubuntu. It behaves exactly the same like booting from the SSD.

[axur-delmeria]

See if that Ubuntu disk has memtest86+.

[karlosss]

It has. I run it - no errors. I also tried using both front and back RAM slot and two different RAM modules - the result is always the same.

[atagunov]

Hmm.. so this T420

- is able to enter BIOS and run memtest86+ w/o issues
- cannot finish boot process for Linux from a USB stick even with the SSD taken out

Just shooting in the blind - can something bad be happening the moment it tries to properly switch to graphics mode?
Is there some way to push your favorite version of Linux to boot into console mode?
I'm sorry, an Ubuntu user myself I have forgotten how things like this are done...

Also I'm sorry I don't know if this T420 is likely to have a discrete graphics card.. Is there anything to toggle in BIOS related to graphics? And while at that you could probably "run wild" switching off various other things in BIOS too.. probably best to keep a record of what you changed.. and double-check computrace is "disabled permanently" in BIOS too..

P.S. I'm pretty clueless here, sorry Just shooting some ideas into the void but I don't really know what I'm talking about..

[karlosss]

Hmm.. so this T420

- is able to enter BIOS and run memtest86+ w/o issues
- cannot finish boot process for Linux from a USB stick even with the SSD taken out

Yes, exactly.

Just shooting in the blind - can something bad be happening the moment it tries to properly switch to graphics mode?
Is there some way to push your favorite version of Linux to boot into console mode?

This is actually an interesting idea - all those systems are graphical. I guess there is a common way that you edit the GRUB script by appending "text" at the end of the linux line - but it still behaves the same. I also tried booting the single-user mode. Nothing as well. Tomorrow I try to create a bootable USB of a console linux in case I am doing this wrong, but I am not really sure it helps. But I'll give it a shot anyway.

Also I'm sorry I don't know if this T420 is likely to have a discrete graphics card.. Is there anything to toggle in BIOS related to graphics? And while at that you could probably "run wild" switching off various other things in BIOS too.. probably best to keep a record of what you changed.. and double-check computrace is "disabled permanently" in BIOS too..

Man, you don't need to apologize for trying to help me . There is both integrated and discrete graphic card - the integrated works the way I described many times, when I enable only discrete, it actually does not reboot, but rather gets stuck at the point it would reboot with the integrated card. I disabled permanently the computrace in bios (it was enabled - factory settings back from 2011), but it made no difference whatsoever. What do you mean by these other things? Like for example network card, AC plug-in beep, or just everything that has hardly something to do with the problem?

[RealBlackStuff]

Linux is not known for liking discrete graphics.
Go into BIOS/Config/Display/Graphics device and select Integrated Graphics.
Reboot.

[karlosss]

I tried all three options:

Both or Integrated: reboots
Discrete: freezes

[atagunov]

when I try to boot into Windows instead, i can see the "starting Windows" screen for about 5 seconds and then the exact same restart happens

So from what we know it does seem likely the fault is somehow related to the graphics card.. Both Linux and Windows not working, not being able to start even from a USB memory stick.. At this point I would start looking for a replacement motherboard on ebay or AliExpress. Hopefully they are not that expensive.

If you're an adventurous type you could perhaps mess with dropping a T430 motherboard instead of a native T420. You'd need to go through the whole classic keyboard mod process of course to make the motherboard work with your keyboard and your CapsLock led would stop working but you'd get a slightly better machine (1, 2, 3, possibly 4 as a preparation stage). Disclaimer: I never owned a T420/T430 so I don't know if for example if the same thing happens as with X220/X230: X220 body has got a hole for a full-sized display port and X230 motherboard has a mini-DP so when you fit one into the other a gap is left around the connector.

[karlosss]

I just created a bootable USB stick with a console-only linux distro and that also does not work. When I was showing it to my friend, I actually got to see the windows login screen for around 2 seconds until it restarted.

I already ordered a new T420, I am currently without a computer whatsoever, so I just take a boring stock model this time - hope it does not disappoint you very much .

But wait...does it mean that both integrated and discrete graphics just died at the same time?

[Screamer]

If both graphics chips died at the same time, you wouldn't get an output from your T420's display panel.

[atagunov]

Us not being repairmen it will be hard to figure out what exactly is wrong with the machine. At the same time motherboards may be inexpensive enough to make the repair worthwhile. Though before ordering a new motherboard I suppose you could try to swap all of CPU, RAM and SSD between your new T420 and this one to make sure it is indeed the mobo that is at fault. Probably WiFi card could also be swapped. They say it's a good idea to re-paste these old machines anyway, so while doing that it will be a good chance to test out the components of the problematic T420.

[axur-delmeria]

Have you tried removing the wifi card?