Need help to recover Bios on Intel BL440ZX / Tek TDS 8000 scope

[benzn]

@Tracker did you ever recover your scope?

I have the same symptoms (B: Drive Error) on a BL440ZX-based TDS7404 after leaving it unplugged for a few months. I've checked all the power supplies (they're fine) and the PPC board boots up to show "L" on the 8 segment display which means it's waiting for the host to come online.

For future travelers, here's what I've managed to do so far (after replacing the CMOS battery):

1. I had a Win98 recovery disk (thank god I made this because I haven't been able to create an MS-DOS boot disk from Windows 10 via a USB Floppy Drive).
2. I've confirmed that this boots into an MS-DOS prompt after I hit F1, because I can run commands even though I can't see anything out of the VGA port (specifically, I can run the BEEP command from the TEK BIOS zip).
3. I've cleared the CMOS using KILLCMOS, this doesn't change anything however.
4. I've run IFLASH with the necessary files alongside from the TEK BIOS zip.
5. I've booted the machine with the recovery jumper off, so that it will attempt to update itself that way.

None of these make any difference, I can't enter the BIOS and I still get the same 1-2 beep as the VGA output dies. Seems like the display controller is truly hosed.

[benzn]

For visitors from the future with the same problem:

Another user was kind enough to image their CMOS settings from a working device and put them into a boot disk which I used to successfully restore my scope. See this post: https://www.eevblog.com/forum/testgear/tek-csa7404-repair-project/msg3095992/#msg3095992