[Dead] C250i BASEB PWB Replacement

[Slammers]

I have a C250i in the field that is failing to boot past 50%.
Boot diagnostics FW JIG reported dead SPI flash on CPU-B and we ordered up a replacement CPU-B.
Issue persists after replacement.
We can load FW/Boot rom etc no problem but machine never goes past 50%.
The internal boot diagnostics (Hold Sub Power + Turn ON) suggests that the issue is related to either Program/FW, CPU-B PWB (This has been swapped) OR BASEB PWB.
I have atatched the exact step of failure from the bulletin. Device is exhibiting the Abnormal operation symptom at this step (All lights remain lit).

I have a spare BASEB-PWB in the workshop and the service manual steps for removal detail removing the TPM Chip (The standoff is one of the securing fasterners to the chassis).
When I insert this into the dead machine, what TPM chip do I use? The one from the spare board (Board Matched) or the one from the dead machines BASEB (Device Matched)?

The Service manual does not detail which TPM chip to use during the replacement process and I was wondering if anyone had any info before I perfrom the swap.
Cheers.

Also, if anyone else has had this boot issue and resolved it, please enlighten me The usual failure I get is the 25%!

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[Synthohol]

is LK-115 installed?
if not i dont think its even being used.

[Slammers]

is LK-115 installed?
if not i dont think its even being used.

Thank you for this. I should have read the section for the TPMB!

The TPM chip cannot even be initilazed unless LK-115 is installed.
The dead machine and parts machine do not have LK-115 so it looks like it won't matter what chip is used.
For my own sanity I will just keep the TPMs together with their respective BASEB and if I have any issues I will update.

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[ThisPete]

Well written original post with all of the information needed Slammers , makes a bit of a change for round here recently 👍

Nice assist Synthohol 😎


Oh, and I thought that everyone knew that:
"is LK-115 installed?
if not i dont think its even being used."


😉

(P.S. I don't actually know what an LK-115 is 😁 )

[tsbservice]

ThisPete

Screenshot_20250808_201809_Chrome.jpg

[ThisPete]

ThisPete

Screenshot_20250808_201809_Chrome.jpg

Thank you tsbservice.. 👍, we no longer deal with Konica Minolta devices and I'm a bit 'out of the loop '...

[Slammers]

Update on this machine.

Swapping the BASEB made no change whatsoever to the 50% boot issue.

It turns out the SSD was toast.

I re-installed the Original BASEB, CPU-B and installed a new 256Gb SSD, flashed the boot rom then the firmware.
Machine sucessfully booted to an errored state (internal error, reboot automaticially).
The machine did this internal error/reboot 3 times before the recover data option appeared, from there it was back to normal.

It should be noted that the CPUB was intiailly diagnosed as the failure point.
The Data Corruption Check / Recovery Jig (GXX-18) reported the following at the initial service call:

SPI-Flash Check:
Result : NG
Replace CPUB

SSD/MicroSD Check
Result: OK
Partition Check: OK

This is where we were taken for a complete joy ride.

Not only did the JIG FW report failure of CPUB, but reported SSD OK.
What also threw us for a loop was the boot recovery diagnosis for getting stuck at 50% ONLY mentions the CPUB, FW and BASEB - Hence why we replaced these boards.

The program load and SSD failure checks are only mentioned at the 75% progress boot step, see my screenshot of the boot diagnostics below with my scribbles.

So, hopefully this may help someone out in the future that a 50% non-boot with a PASSING JIG SSD Parition Check should be treated as a SSD failure until proven otherwise.

This wasted so much time when i could have turned up with a SSD and a memory stick, instead of a CPUB, BASEB and a temporary C308!!!! while I waited on the parts.

image.png

[Slammers]

Well written original post with all of the information needed Slammers , makes a bit of a change for round here recently 👍

Nice assist Synthohol 😎

Thank you ThisPete , I always try to follow the guides and provide the information that I would ask for, so many posts that assume you have a crystal ball in your tool bag. Also, Synthohol your guidannce and responses on this site have made me a better tech.
Cheers all.

[ThisPete]

Nice one Slammers, good result in the end, and I'm sure someone will appreciate your coming back with your solution.. even though you may never find that out... 👍

[tsbservice]

Slammers, We really appreciate you coming back with solution. I know what to expect from almost everyone contributing actively to this site and you proved me absolutely right on what I was thinking about you.

P.S.
In my experience Base board is never found culprit for dead machine, it's always CPUB or Storage board.

[stronghold]

I have a C250i in the field that is failing to boot past 50%.
Boot diagnostics FW JIG reported dead SPI flash on CPU-B and we ordered up a replacement CPU-B.
Issue persists after replacement.
We can load FW/Boot rom etc no problem but machine never goes past 50%.
The internal boot diagnostics (Hold Sub Power + Turn ON) suggests that the issue is related to either Program/FW, CPU-B PWB (This has been swapped) OR BASEB PWB.
I have atatched the exact step of failure from the bulletin. Device is exhibiting the Abnormal operation symptom at this step (All lights remain lit).

Greetings.

Your request has some nuances that we’d like to clarify:

1. Is an **NVMe SSD** or a **microSD card** installed as the primary storage?
- *If NVMe, what type is installed: 64-layer or 112-layer?*

2. Does **Service Mode** boot when holding down the **Reset button** (located on the back of the display)?

3. Have you performed **HDD formatting** (internal memory)?

4. Have you **reset the Encryption Key** on the SSD using the utility FW JIG?

[Slammers]

Greetings.

Your request has some nuances that we’d like to clarify:

1. Is an **NVMe SSD** or a **microSD card** installed as the primary storage?
- *If NVMe, what type is installed: 64-layer or 112-layer?*

Original Drive:
B + M Key 64 layer KBG3AZMS256G This is a Toshiba branded drive

Replacement:
This has now been successfully replaced with a 96 layer M Key drive after updating storage controller firmware during the boot rom upgrade process.
Replacement is a Kioxia (Toshiba's SSD division spin off) KBG4 series 256Gb

2. Does **Service Mode** boot when holding down the **Reset button** (located on the back of the display)?
Service mode was not accessible during our testing and the diagnosis we performed was pointing to CPUB - The jig was passing the SSD so we did not investigate until after performing the other steps I detailed in my update.

3. Have you performed **HDD formatting** (internal memory)?
No service mode access available at time of diagnosis, hence the boot diagnostics and JIG. We would have perfomed a full self test if this was the case which would likely have flagged the SSD Pattern Check as NG.

4. Have you **reset the Encryption Key** on the SSD using the utility FW JIG?
SSD was passing on the JIG FW so we did not think to perform this step during diagnosis. Again, if you read my update, the JIG FW was reporting SPI Flash NG SSD OK.

Machine is operational as of now and the job is closed.

[Slammers]

stronghold I should add that your post about the CPU boards and SPI Flash has been a great help for this job and others I have had.

My reply kinda comes accross as rude and that was not my intention, hopefully you saw that I have embedded my replies to your questions in the quote section!

This machine was just being weird in the fact that the FW JIG and boot diag were all pointing to the CPU board, especially since service mode was not available. The end result was just the STRGB SSD being replaced, the device is running on its original CPUB and BASEB. I ran the JIG after sorting it all out and SPI is reporting OK now.

If you need anymore info for your own records, please let me know!

Also, what programmer/jig do you use for reading the SPI flash chips? I have a board here I want to tinker with myself and could be a fun exercise. I also presume you have to de-solder the chips from the CPUB to read them on the jig.

[Esron Thomas]

I have a C250i in the field that is failing to boot past 50%.
Boot diagnostics FW JIG reported dead SPI flash on CPU-B and we ordered up a replacement CPU-B.
Issue persists after replacement.
We can load FW/Boot rom etc no problem but machine never goes past 50%.
The internal boot diagnostics (Hold Sub Power + Turn ON) suggests that the issue is related to either Program/FW, CPU-B PWB (This has been swapped) OR BASEB PWB.
I have atatched the exact step of failure from the bulletin. Device is exhibiting the Abnormal operation symptom at this step (All lights remain lit).

I have a spare BASEB-PWB in the workshop and the service manual steps for removal detail removing the TPM Chip (The standoff is one of the securing fasterners to the chassis).
When I insert this into the dead machine, what TPM chip do I use? The one from the spare board (Board Matched) or the one from the dead machines BASEB (Device Matched)?

The Service manual does not detail which TPM chip to use during the replacement process and I was wondering if anyone had any info before I perfrom the swap.
Cheers.

Also, if anyone else has had this boot issue and resolved it, please enlighten me The usual failure I get is the 25%!

image.png

I have the exact same issue with a c360i last time, I happened to replace cpub with the latest Firmware and boom! The machine coming back alive with meter readings reset, everything back and I have to do normal run up for the machine.

[copier tech]

We've also had this exact same issue of a few devices. Each time it was either the CPU or SSD board both exhibit the same symptoms.