Can't locate/ID.this chip for the life of me. Anyone care to take a crack at it? - Page 1
Forum section: electronics / repair

author: FloridaCaveDiver
author_rank: Newbie
timestamp: August 19, 2024, 02:10:21 am
content: I have spent hours trying to ID and locate this chip. I need to replace one to complete a repair.I have attached a photo... any help would be VERY appreciated. There are two of them located on the back of a Keychron V8D2 keyboard mainboard.I believe it is 22C31WB0c e3Thank you in advance for any help!

author: amyk
author_rank: Super Contributor
timestamp: August 19, 2024, 02:19:46 am
content: If you can figure out the pinout, that would help narrow it down as I suspect it's an MCU but there are tons of them in QFN40.

author: fzabkar
author_rank: Super Contributor
timestamp: August 19, 2024, 02:57:11 am
content: Quote from: amyk on August 19, 2024, 02:19:46 amI can't think why one would need two identical (?) MCUs on a keyboard? Am I living in the Dark Ages? :-?

author: darkspr1te
author_rank: Frequent Contributor
timestamp: August 19, 2024, 07:02:32 am
content: Are there any other chips ? these could be identical MCU's , one is the io keyboard sense side the other could hand the USB side &/or rgb. i would make sense if you already have a build environment and ran out of IO on one chip and didnt want to use a IO expander,Now if you have maybe 3 chips on the pcb then one could be the actual MCU and the other could be IO expanders. these are just my guess though,darkspr1te

author: gamalot
author_rank: Super Contributor
timestamp: August 19, 2024, 07:26:03 am
content: Looks like a customized EFR32BG22 series MCU.

author: m k
author_rank: Super Contributor
timestamp: August 19, 2024, 01:07:39 pm
content: Quote from: fzabkar on August 19, 2024, 02:57:11 amPC and Mac?

author: fzabkar
author_rank: Super Contributor
timestamp: August 19, 2024, 03:02:08 pm
content: Quote from: m k on August 19, 2024, 01:07:39 pmI recall PC keyboards where you could select XT mode or AT mode via a switch. They still had a single MCU. I don't think the data transfer rate (2 bytes per second?) has improved since then.

author: Haenk
author_rank: Super Contributor
timestamp: August 19, 2024, 06:07:39 pm
content: Now *that* was easy."MCU: Ultra-low-power ARM Cortex-M4 32-bit STM32L432 (128KB Flash)""The open-source firmware means endless possibilities for keyboard layouts, shortcuts, backlight effects, and more."https://www.keychron.com/pages/firmware

author: fzabkar
author_rank: Super Contributor
timestamp: August 19, 2024, 06:22:30 pm
content: Quote from: Haenk on August 19, 2024, 06:07:39 pmThat's a 32-pin package. :-?https://www.st.com/resource/en/datasheet/stm32l432kb.pdf

author: Haenk
author_rank: Super Contributor
timestamp: August 19, 2024, 09:11:03 pm
content: Quote from: fzabkar on August 19, 2024, 06:22:30 pmThat's from the product description page, so don't blame the messengerAt least it should help to understand the technology used, maybe they switched to a chinese clone (chip shortage?) - it should still be possible to flash these with their software.

author: fzabkar
author_rank: Super Contributor
timestamp: August 19, 2024, 10:06:39 pm
content: I can't see a crystal or oscillator in the OP's photo ...Could we see a photo of the whole PCB?

author: m k
author_rank: Super Contributor
timestamp: August 24, 2024, 07:16:58 am
content: More surrounding components would be better.My take is that 1 is not 1, so 22C3|Wc e3.1st C can be 12, so made 22/2023.Is lower part of a logo 'together' (hé sī).E,obviously C is 12.

author: ArdWar
author_rank: Frequent Contributor
timestamp: August 24, 2024, 08:16:10 am
content: If there are wireless version of this keyboard family there might be merit into suspicion that it's a clone of STM32WB series. Not necessarily a full clone, but at least functionally similar. That's what Chinese OEM supplier often do (e.g. STM32WB-like peripherals but using 51 core etc)

author: m k
author_rank: Super Contributor
timestamp: August 25, 2024, 12:52:50 pm
content: What's 0c then, different package and mask ROM, of version e3?

author: fzabkar
author_rank: Super Contributor
timestamp: August 25, 2024, 05:12:20 pm
content: https://electronics.stackexchange.com/questions/2428/what-does-the-e3-or-e4-printed-on-an-ic-mean"e3" is most probably an RoHS mark.

author: m k
author_rank: Super Contributor
timestamp: August 26, 2024, 05:20:44 am
content: Maybe end part is a diversion and a real thing is 30ce.What is that missing pin marking of end of 1st side?If that last marking is real all sides have hiding pins.