[ot][spam][crazy][personal] thinkpad tp25 anniversary edition
i’ve been using a gift tp25 for some years. it’s a special lenovo laptop edition that is similar to the t470 and t480. as the years have passed, it gets harder to find information on repairing this laptop online. last time or two ago i replaced the system board, i engaged a long list of substitute part numbers for system boards that would fit and boot. i haven’t found this list again. i originally made it by looking at simple commonalities on support.lenovo.com and ebay.com , but simple search terms do not return as many results now as they did before, and support.lenovo.com is only showing one system board now for my model number. i’m seeing these values in the bios atm: bios ver: N1QETA3W ec ver: N1QHT54W model: 20K70004US unit serial: PF12XKZP board serial: L1HF83M000D cpu: i7-7500u 2.7ghz uuid: 1f4bfcc-2c71-11b2-a85c-955ac813bb93 os license: SDK0J40697 oa3 id: 3305102936368 may have made copy mistakes the problem i have right now is that the system does not charge, instead emitting a pungent smell for some time after the charger is plugged in. i removed the bottom cover but
the problem i have right now is that the system does not charge, instead emitting a pungent smell for some time after the charger is plugged in.
i removed the bottom cover but
i removed the bottom cover but the smell didn’t seem to come from any particular area, similarly i didn’t find any areas that were hot nor see any burnt components although my vision is poor these years. i suspect if there is something glaring that it’s on the back of the system board which i did not remove yet. i also removed the dc-in assembly which is protected by a solid steel cover attached to the lcd hinge which can be unscrewed without removing anything else and hinged back. i tested its conductivity and it seemed reasonable: 20v to both positive wires, two wires for one ground and one wire for another. one of the ground wires gave some low voltage or resistance or such, but it didn’t alarm me. i thought the smell might have been coming from near where the second internal battery is wired, on the other side of the board, but not sure really. i have this battery unplugged as it has failed, and was going to pick up the replacement today.
so basically on support.lenovo.com you have to select “machine type” rather than “as-built” to see other compatible boards :) oops ! WIN,i7-7500U,N-TPM2,SWG SYSTEM BOARDS 01LV688 NOK,i7-7500U,Y-TPM2,SWG SYSTEM BOARDS 01LV689 NOK,i7-7500U,N-TPM2,SWG SYSTEM BOARDS 01LV690 Lenovo BDPLANAR WIN,i7-7500U,Y-TPM2,SWG SYSTEM BOARDS 01LV687 It used to show a different kind of part number than just the 01LV ones, I think there is one that is like HX or something … yeah seeing this on ebay. then websearching further values finds other sites with compatibilities compatible boards 01LV679 01AX967 01HX644 01LV687 01HX692 01LV688 01LV689 01LV690 01HX602 01HX660 compatible laptops (note people have made the t480 interchangeable too) T470 20HDCT01WW T470 20HES44K00 T470 20HDCTO1WW T470 20HES99L00 T25 20K70005SG there are a _lot_ of boards in this group and it’s hard to know how far out to go. it’s cheapest to get one without its old nvidia gpu but i’ve probably gotten used to pytorch running at a certain speed :s my library computer session is ending
more board numbers 01HX645 01LV679 01HX672 getting to know t470 models and gpus T470p 20J6CTO1WW - i5-7300hq hd630 20J7S0CR08 - i7-7820hq 940mx with 01YR891 (looks like different form factor) 20J6S0FC00 - i7-7700hq 940mx with 01YR903 (similar form factor to 891) T470s 20JS0015US - i5-6300u hd520 20JS0004US - i7-6600u hd520 T470 20JM0009US - i7? (lenovo site displayed no cpu) hd520 20HD0068US - i5-7300u hd620 20HES6HC00 - i7-7600u hd620 20HES88S00 - i7-7600u hd620 20HES0MV00 - i5-7300u hd620 so there’s a reddit thread that says you can out lots of motherboards in the tp25 but it has been deleted, but i found an archive and found this: - you can charge the tp25 via the usb-c port 0.0 - they recommend not using 470p or 470s mobos - they say all t470 mobos work but most lack the nvidia 940mx which was a rare option … definitely makes sense to try charging the machine with usb-c :s :s :s
… definitely makes sense to try charging the machine with usb-c :s :s :s
so first i tried a usb-a to usb-c cable to not burn anything out too badly, and the charging light lit !! but with weird brightness subtleties, and the power light lit !!! but then it turned off and the charging light turned off and it’s not responding when disassembling it was powering off only the battery (but not yesterday when it stopped charging) but not now after this plug-in. so it seems the charging failure breaks battery boot. reseated the battery. still nothing. i tried a usb-c to usb-c cable but still nothing, no charging light. guessing maybe there’s a short or such that is causing other components to burn out when used somehow
compatible boards
if you don’t need nvidia, just get a cheap t470 board. you can see which of the below have a tpm at thinkpads.org with some finegling images for some parts seem presently at https://download.lenovo.com/Images/Parts/[model]/[model]_[idx].jpg where [idx] is A, B, C, … . many don’t have official part photos.
it looks like boards without nvidia have three large prominent empty chip footprints that are filled on boards with nvidia. the below are mostly listed as having nvidia. the numbers in the gaps have intel graphics and are also purportedly compatible. 01HX602 according to one site 01HX640 01HX641 01HX642 01HX643 01LV679 01AX967 01HX644 01HX645 01HX646 01HX647 01HX656 01HX657 01HX658 01HX659 01HX660 01HX661 01HX662 01HX663 01HX672 01HX673 01HX674 01HX675 01HX676 01Hx677 01HX678 01HX679 01LV675 01LV676 01LV677 01LV678 01LV679 01LV680 01LV681 01LV682 01LV687 01HX692 officially listed for tp25 01LV688 01HX693 officially listed for tp25 01LV689 01HX694 officially listed for tp25 01LV690 01HX695 officially listed for tp25 T480 boards start with 01YR and 01YU compatible laptops (note people have made the t480 interchangeable too)
T470 20HDCT01WW T470 20HES44K00 T470 20HDCTO1WW T470 20HES99L00 T25 20K70005SG
so i had searched for the 01HX640 first because it was first numerically so i imagined it being the lowest end and cheapest, but it has discrete graphics so it has the gpu, and it was available for only $25 0.0 which was nothing compared to what i found before i made the list, some sites had them for over a thousand usd, other sites at least a few hundred. so i just ordered that one when i saw it and i picked it up today. i just finished removing the old system board and the new one fits perfectly, it has the same form factor. we’ll see if it works :s also i forgot to get thermal paste (again) so it’ll be running hotter 1602 1636 well i put it back together, and the leds for the batteries charging work when it’s plugged, but - oh! :) ok it bootlooped a bit without display, and then after some bootlooping it displayed the lenovo logo and gave a bunch of errors that would be normal with a blank cmos after replacing the clock battery :) yay 1638 so all these t470 boards likely replace my exotic board for real 0.0 there were no seating issues anywhere or anything. 1728 bios had a big update. machine type and serial number are wrong, which makes loud beeps on boot. need an external disk to fix it the normal way, can consider that next to the thermal paste i guess. internal battery wasn’t recognised, eventually reopened the system and found the connector wasn’t all the way seated. does retain some power to leds with all other power sources removed under those conditions. upon thaw after reassembly got a kernel panic, maybe because devices changed from hibernated image. runs after another reboot. note, because of my situation of having a dissociative disorder, it was quite helpful to find a label inside the system saying it worked with T470 boards. such notes are so useful and i transferred it to the new board.
This system was stolen along with most of my possessions on Jan 5th, 2025. I had replaced the board without setting the numbers, so the stolen system had blank serial and model numbers in the bios. It also had an international keyboard (I think for a nordic country, it was just the cheapest when i needed a replacement) which is unique in the united states. The bios had appeared to have begun misbehaving to me in that it usually did not give the bootup beeps. Most of anything I had been doing was on this machine and I have significant grief around its loss. It was inside a toolbox with many other items that had previously been checked as luggage. It was stolen the morning after I got off the plane, with my vehicle.
This system was stolen along with most of my possessions on Jan 5th, 2025. I had replaced the board without setting the numbers, so the stolen system had blank serial and model numbers in the bios. It also had an international keyboard (I think for a nordic country, it was just the cheapest when i needed a replacement) which is unique in the united states. The bios had appeared to have begun misbehaving to me in that it usually did not give the bootup beeps. Most of anything I had been doing was on this machine and I have significant grief around its loss. It was inside a toolbox with many other items that had previously been checked as luggage. It was stolen the morning after I got off the plane, with my vehicle.
The system dual booted to linux and windows with grub. The linux OS waits during boot for an encryption passphrase to be entered, which can make it appear as if the boot has hung as the prompt to enter a passphrase tends to not be visible.
participants (2)
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Baffo 32 -
Karl Semich