I just wanted to make a short post today on how I fixed a laptop I thought was fully toast.
The Story
This story being months ago, a user’s laptop wouldn’t boot properly following a Windows Update. Taking a look at it, and after he mentioned it just going into a “looping cycle” it was acting really weird! Symptoms of the device:
- The system would boot into the EFUI/BIOS menu without any issues, and could stay running here endlessly.
- The system could run all EFUI based hardware testes, and all reported functional hardware with no faults.
- As soon as you would get into the boot loader of any OS, the system would hard shutdown and power back on, wash, rinse, repeat.
What had me so baffled was that any OS boot would cause the hard shutdown (power lights all go off, screen goes dead blank), and then the power LED would come back on, and the POST screen would show, If I interrupted it, by going into the BIOS or doing self tests, it wouldn’t hard shutdown at all.
I tried everything (I had a few of these laptops already taken apart, so even tried swapping all the parts, including the battery (which is these particular laptops source of power for the CMOS) yup, the laptop battery is the BIOS config saving power source. However even that didn’t fix it, and thus it sat on a shelf for months.
Till Today
I was working on another project when I got hit with a layer 2 segregation issue in the design plans, which had me really upset, and mind hurting. So I decided to step back from the problem and just happed to have this particular laptop on my desk that day as I needed some laptops for testing and realized it was this machine, so it just sat there.
I decided to take another shot at it. Since I was already on a path of failure, figured what’s the worst, just a bit more wasted time before going home.
So anyway, I thought I might as well see if there’s some new firmware and maybe that might help fix it (seems almost firmware related). So low n behold I grab the latest firmware for this laptop and create a “recovery USB stick”, then find out you simply plug that USB stick into the laptop, power off the machine, press n hold the “Windows Key + b” then power the unit on while still holding that key combination.
Holy crap, first time I follow instructions and it actually works, mind blown. So it completes the firmware update, everything seems find try to boot a linux OS from a USB drive. Boot loop, ahhh FFS.
I decided to vent my fustrations on the local #SkullSpace IRC channel, and another IT tech from the states, said something of the usual nature “Open and reseat all the things?”. Which of course as I stated about had a couple of these already open for repair and swapped all the goodies with no different result.
When I made the moment back to them about what I stated above: “I tried everything (I had a few of these laptops already taken apart, so even tried swapping all the parts, including the battery (which is these particular laptops source of power for the CMOS) yup, the laptop battery is the BIOS config saving power source”, and when I mentioned that to them I noticed I had done the whole firmware upgrade without the battery plugged in at all.
I decided to plug in the battery and try to boot (of course this was always done before so didn’t think anything of it), when I booted it stated the CMOS had been reset (well yeah the battery was unplugged the whole time), and pressed enter to continue… and it didn’t boot loop.
At this moment I was like “WTF”. I was blown away to see after months of collecting dust I somehow magically managed to get this laptop to boot normally.
That’s what I call a good way to end the day…. now about that layer 2 segregation issue….
*Update* It went right back into the OS boot loop, it’s effed. 😉 would require a full mainboard replacement, not happening.
