Attempting to get working continued
-I tried the same with a 2GB CF card and adapter (image A6), the 2GB image was too large according to Win32 Disk Imager, but the 815MB image went on fine. Still no change in behaviour

-At this point i tried to upgrade the BIOS. I got a 70CT BIOS file from https://ia600708.us.archive.org/view_archive. … tto%20L70CT.zip. I have an extranal USB floppy and an old WinXP laptop, I ran the 6.40 BIOS program on Win XP and it wrote the files to a 1.44MB disk. I then copied GHGBIOSA and BIOFCE6T to a 720k disk. The Toshiba floppy drive and disks were verified by connecting the PCMCIA floppy drive to my XP machine, and although it saw it as a 5 1/4 inch floppy, and it took quite a while to read, i did end up seeing the files on the disk. So i'd say the drive and disks are working.The procedure i then did was power on Libretto with F12, update BIOS screen displays, insert disc into PCMCIA floppy drive, press any key, disc drive makes a read noise, but then just whirs, screen goes black, waited 5+mins. Video of this at https://youtu.be/xscnxCB8XYE

-Unable to update the BIOS, i moved back to something else.

-I also have a SD card adapter with a 4GB SD card (image A7). I wrote the 2GB image to this and tried it in my Libretto, something different happened this time! Along with the power and on LEDs, the HDD LED was now a solid green! (image A8). Alas no change in the screen, its still black. I also tried powering on with FN+F5 pressed, and again trying Esc pressed whilst powering on, no change.

Next Steps
Try a proper 70CT image on the SD card, i believe this should be 1.6GB, as is my original HDD that came with it.
I could attempt to get another PCMCIA floppy drive, but these are £100-£200 on ebay for the Sony version, so i dont think i'll be doing that.
Try flashing just DOS to the SD card with the HP tool (https://www.malavida.com/es/soft/hp-usb-disk- … ge-format-tool/) and attempt to boot.

Question for Vogons
I've read that if the Libretto was hibernated rather than switched off this can cause issues. Does anyone have any experience with that?
Looking at the images of the board, could any of this damage have any affect booting normally from a HDD?

Not that it'll help, but I do have a port replicator for the libretto M3, the port isn't in the right place for the 70CT, but I took it apart, turned it round and it fits perfectly.

I've now procured a Sony PCMCIA floppy drive and its having the same effect, the floppy gets read for a couple of second and then just whirrs, as in my previous video.
What i would love to see is a video of a BIOS update being done on a Libretto 70CT (or 50CT) which completes successfully, just so i know what i *should* expect.

I would also love any replies from Vogons users who have any experience with any of this. Any comments or tips would be gratefully appreciated on this one!

I believe that the BIOS chip was damaged/fried and now the BIOS is missing, as is the ability to update it. So find donor with broken screen and replace screen/motherboard.

I'm leaning towards that as well.
I'd like to try and source a new chip first, although it would be way beyond my soldering ability!
The BIOS flash chip is a 29F200TA-??PFTN, I cant quite make out the middle two numbers.
Looks like its still in production
https://www.jotrin.com/product/parts/29F200TA … xi_pmblWLbdIvDf

Alas it does look my journey has come to an end!
I had a port replicator from a Libretto M3, which didnt fit the 70CT, however when i took it apart and turned it round, it fit the connector!
Looks like powering it up with this on was a bad idea as now plugging the power in does nothing, not LEDs light up at the top at all.

So if anyone is looking at adding an M3 port replicator to a 70CT DONT DO IT!!!

Best case - you burned some fuse on the motherboard, check if there is any component marked as F1 (or anything starting with F) near the power socket.

bionicsa wrote on 2026-02-20, 14:11:

Alas it does look my journey has come to an end! I had a port replicator from a Libretto M3, which didnt fit the 70CT, however w […]
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Alas it does look my journey has come to an end!
I had a port replicator from a Libretto M3, which didnt fit the 70CT, however when i took it apart and turned it round, it fit the connector!
Looks like powering it up with this on was a bad idea as now plugging the power in does nothing, not LEDs light up at the top at all.

So if anyone is looking at adding an M3 port replicator to a 70CT DONT DO IT!!!

Did you check the pin out of both docks? Or did you assume because it was physically the same connector it would work?