Hey everyone,

I've got a broken Lenovo Ideapad 500S-14ISK lying here which doesn't boot anymore. Amber light flashes when plugged in, but power doesn't come on. Different charger, same symptoms. Now the repair shop said it must've been one of the mosfets that went south. However, this BIOS update suggests that it might be fixable just by a bios update: https://pcsupport.lenovo.com/ie/en/produ...nloads/ds105316

But since the device doesn't come on anymore, how do I do that? I've tried reading the BIOS using my SOIC8 clip. It's a Winbond W25Q128FV (16 MB). Using CH341A (black PCB with 3.3-V-fix) I can dump the bios, but if I compare different dumps, only roughly the first 8 MB are identical (and they are not just FFFFFFF...), while the rest shows some differences. Doesn't matter if I leave battery and/or CMOS battery connected or not. How is that even possible? If I try to open a dump in UEFITool, I see some stuff. UBUTool v1.69 fails to identify this BIOS, v1.70 only reports broken microcode.
Furthermore, if I use TL866A programmer I only get a warning for surge/over-current protection and it refuses to read the chip.



Now if I download the latest update from Lenovo's homepage and extract the package, I get a ~8.5 MB big .cap file. This one opens fine in UEFITool and also UBUTool v1.70 is able to decipher this (PhoenixSCT).

But I guess I cannot SPI flash a cap file onto the chip. And ME will be a problem? Also, what's with the different 2nd part when reading the chip?

Is there actually any way to update this bios? Should I maybe desolder the chip? (maybe I can externally charge the battery and power up the device, and then flash the bios).

@treysis Dump your BIOS using ASProgrammer 1.4, I've tested all versions of Ch341A software (including latest 1.34) with W25Q128FV and W25Q128FBV, none work properly for all operations so it's not to be trusted.
https://github.com/nofeletru/UsbAsp-flash/releases/

Don't write anything until we confirm you've got a good backup, upload and I will check. You can program in BIOS once we're sure you've got a good backup done, no soldering will be needed since you have a clip

So, about the battery, is it drained now, and not charging if you leave it all plugged in to charge? On the BIOS info, I see some issue described but not one that exactly points to your symptoms, it's possible that's what it's describing though, so we'll see once we get a proper dump from the chip.

The battery doesn't charge when plugged in. I disassembled it and the cells had only 2.6 V each. Charged them with a bench power supply, ~4000 mAh battery in 2S1P configuration, so I charged directly at the cell terminals using 8.4 V and 2 A until current dropped to about 400 mA.

However, I made a cardinal mistake. I tried to analyze the board with a multimeter, and I accidentally shorted V+ with the middle pin of the charger (Lenovo chargers have three pins: V+, GND, and the middle pin with a specific resistance to GND to identify the power rating of the charger). I get no lights at all anymore. The charger is still fine. I only notice one IC (step-down controller) on the board is getting quite hot and the board drawing a constant 200 mA at 19 V! Now I don't know if that IC was heating up before I shorted the pins as well. I'm surprised however that the board didn't have any protection against reverse current. Also, I don't get any 3.3 V or 5 V (anymore?) on the board, and I don't have any schematics for the board neither.

Anyway, board seems toast now. Ordered a spare one. Maybe I'll find some time to replace the IC, if I can source the part from somewhere. For sure it's not economic anymore (considering the time necessary), but yeah, we do this mostly for fun, don't we?

REMARK: Thx btw. for suggesting ASProgrammer! That tool did work (read chip, verify succeeds!). Seems like the original CH341 software can only properly read the first half of the chip and then does something weird. Probably it doesn't know how to properly shift to the next bit or so. ASProgrammer does, though. Also read out a new unsoldered empty W25Q128FV. With original software, only first half is empty (FF), second half appears random. With ASProgrammer all comes back as FF as expected.
BIOS seems to use BootGuard. First time I come across this, so I got some reading to do :)

Bummer to hear about the short!! You're welcome on the ASProgrammer! Yes, CH341A software needs update or fix for W25Q128FV, I wish I knew who to contact to ask them to check and correct. Of course they probably would, but then only make available in the paid version

Yes, we mod for fun! Sometimes that costs us though Hope you didn't have to pay too much for the replacement board

BIOS using bootguard and board setup to use bootguard (properly) are two different things. How did you see it has boot guard? It can only work, if the PCH fuses have been burned in with a boot guard key, this can be checked with MEInfoWin - verbose, on a running system.
In that MEInfoWin report, at the bottom, on Measured Boot and Verified Boot if it says enabled on the left FPF side that means burned into PCH/chipset. When you see that it's enabled and cannot be worked around, when you see disabled on the FPF side, then it cannot be correctly enabled otherwise, no matter how the BIOS/ME is setup.

I can only find the schematic for 300-14ISK 300-15ISK 300-17ISK, if you think it would help let me know and I'll upload for you.