Years ago I found a FIC PAC-2003 LPX mainboard in poor condition. I cleaned it, replaced some parts, upgraded VIDEO-RAM and installed the latest BIOS.
It worked fine with a Pentium MMX 233 (AMD K6-2 CPUs overload the onboard VRM with its tiny heatsink).

Onboard there´s 256K PB-SRAM and I thought why not upgrade for 512K by populating the COAST (CELP) socket with another 256K?
In most cases this is a no-brainer, so I set the jumpers "SRAM1" and "SRAM2" accordingly. The jumpers allow to hook A13 and A14 of the TAG-RAM to either 5V or to the chipset / CPU for 512K or even 1M cache. The VIA "Apollo VP" chipset supports both.

After setting the jumpers and inserting a COAST module I was diasappointed when the POST screen reported "none" instead of 512K cache.
First I suspected the CELP slot´s contacts to be corroded / dirty after decades without a module, but cleaning wouldn´t help.
Next I tried dozens of different COAST modules and all possible jumper settings t0 no avail. I also tried an original FIC module just in case they did some proprietary configuration here (which wouldn´t be "FIC-like" btw). Unless staying with the 256K onboard configuration everything else turned out "none".
Interrupted traces, vias, chipset pins etc. could also be ruled out safely.
I then decided to put this mainboard aside - until today.

First I measured all the pins of the CELP slot and found out the clock connector was "nc"! Following the trace from the slot to the clock-generator finally revealed the culprit: The resistor between the clock-gen. output and the trace to the CELP slot had not been populated. Shame on the FIC QC guys...

After soldering a 10R resistor 512K L2 cache are fully operable now.