Looking at the card, it says Blue Lava Systems XT-CF Bootable 8-bit CF Interface
The 'Blue Lava Systems XT-IDE Deluxe (XT-IDE CF+)', shown at [
here].
( A clone of the Monotech XT-IDE Deluxe Rev1.0, shown at [
here]. )
Any ideas how to troubleshoot/fix the non-working one I have?
I've tried pulling it apart and re-seating it. No luck.
These cards are essentially two circuits/blocks, per the illustration at [
here].
BIOS ROM circuitry
The photo in in post #27 reveals that the 'BIOS ROM' circuit is working.
And we know that the XUB in the ROM is not mis-configured (because, the card was working, and without provocation, stopped working).
IDE interface circuitry
Per [
here], the XUB (via the IDE interface circuitry) is not 'seeing' a CF card (the contents of any CF card being irrelevant).
CF card ruled out because in post #12, you state that you tried a different CF card (and we know that the 'XT-IDE Deluxe (XT-IDE CF+)' is not restricted to CF's that can do 8-bit transfers).
You have re-seated the piggyback board.
The card contains a couple of fuses, but they are for the 4-pin power jack (i.e. no impact on the dedicated CF connector).
Try changing the setting of the 'hi-speed' mode switch a few times.
Do the same for the three 'IDE address' switches a few times, returning them to all OFF.
A thorough visual inspection, with focus on solder joints.