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[FIXED] T440p won't boot, 3 flash, pause 3 flash

Posted: Wed Jul 10, 2019 11:14 pm
by rottgrub
Hello all,

I've been a long time fan of Thinkpad hardware, and recently decided to try my luck putting together a working T440p from parts. Unfortunately, I may have picked a loser, as the motherboard doesn't want to power on.

When I plug in power, the CPU fan twitches, and the power light on the power button will blink three times, pause, and then blink three times again. When I press the power button, the same 3 and 3 blink pattern happens. It doesn't beep at any point.

I have removed the battery, CMOS battery, wifi card, keyboard, DVD drive, and tried with a single known good memory stick in either, or neither memory slot. I've held power for 10 seconds, 30 seconds, 60 seconds, with and without power cord attached.

Oddly, if I hold the power button, and then plug it in, the power button light stays on, but nothing else happens.

Kinda thinking dead motherboard, but since this pattern seems to be pretty common, I thought I'd ask here first before plunking down on a replacement. Any and all community wisdom is appreciated!

Cheers!

Re: T440p won't boot, 3 flash, pause 3 flash

Posted: Thu Jul 11, 2019 12:11 am
by BillMorrow
welcome to the forum..
did you check the hardware maintenance manuals.. the one for your thinkpad..? look UP there to the "HMM" link..

Re: T440p won't boot, 3 flash, pause 3 flash

Posted: Thu Jul 11, 2019 8:25 pm
by rottgrub
Thanks, I've been scouring the net looking for anything relevant, but no luck. Used the HMM to confirm cables and device locations. Nothing really specific about the 3flash, 3flash thing. 3flash is usually just a sign of power being applied, and it seems like there is power making it to the fan at the very least, but it doesn't seem to be bootstrapping to BIOS/POST at all.

Wondering if there is a fuse or something that could be blown. Lacking any "AHAH!" moments, I'm probably going to pull out the MB, and break out the tester this weekend.

On the good side, I won a second (working) T440p auction for $30, and $15 shipping. At least I won't be down a system while I noodle this out.

Cheers!

Re: T440p won't boot, 3 flash, pause 3 flash

Posted: Sun Jul 21, 2019 10:37 pm
by rottgrub
Laptop FIXED!

For those who are interested in the resolution, I ran down a bunch of things before finding the dead part.
  • 5s, 30s, etc reboot with batteries removed: Same issue.
  • Tried known good RAM: Same issue.
  • Tried multiple different power supplies: Same issue.
  • SPI FlashROM'd the BIOS, to a known good ROM: Same issue
Okay, gotta be a dead motherboard at this point, so:
  • Purchased and swapped in a known good motherboard: SAME ISSUE.
Wha?! .... After that, I figured it had to be the charging circuit, power button, or ... could it be the CPU? I've been doing IT for 25 years, and had only seen one CPU (out of thousands) die during that time. Well, now I've seen two. I swapped in a new CPU, and the system booted right up. Woot!

Of course, now I have a pile of spare parts I don't need...

Re: [FIXED] T440p won't boot, 3 flash, pause 3 flash

Posted: Mon Sep 30, 2019 10:21 am
by olddog
Rather a late reply....

Glad you got it working.

You should be able to resell the second T440P for a lot more than you paid for it. Probably you have already done so.