For archival and historical reference, I'm documenting the restoration process of my Sanyo 16LT2 luggable PC and, specifically, my successful efforts to map and utilize its unpopulated ISA expansion connector.

Key Specifications:

• CPU: Intel 80C88 (CMOS version) switchable between 4.77 MHz and 8 MHz.
• RAM: 640 KB installed.
• Storage: Two 720 KB (3.5-inch) floppy disk drives (Model 16LT2).
• Graphics: CGA output via the Yamaha V6366B-F controller chip.
• Ports: 1 x LPT, 1 x RS232 and 1 x RGB output.

The machine arrived in a non-working state and had the original 10V adapter included (adapter was fine). The failure point was traced to the power supply board, which is physically attached to the mainboard.

The issue was leaking electrolytic capacitors on the power supply board. I had to replace all capacitors on this board to restore functionality. I also cleaned the power supply board thoroughly after replacing the components to prevent long-term trace damage. The internal NiCd battery pack is also highly prone to leakage. Fortunately, on my machine, the leakage did not spread to the mainboard, but immediate inspection and removal/replacement of the battery is strongly advised for any Sanyo 16LT2 owner.

I investigated the possibility of utilizing the mainboard's unpopulated expansion connector. This connector is an excellent access point for adding a standard 8-bit ISA card (e.g., compact flash).

Connector Mapping Confirmation
The connector is a 4 x 17 pin header (could have been a VHDCI 68 pin connector?). I have confirmed that this header maps exactly to the full standard pinout of an 8-bit ISA slot:

• The first 2 x 17 pins map to the B-side of the ISA connector.
• The next 2 x 17 pins map to the A-side of the ISA connector.
• The final 3 remaining pins at the end are all unconnected as they all map to Ground (GND).

So you can wire a standard 8-bit ISA edge connector to this header based on the following pattern:

I'm still looking at the BIOS assembly to see if I can find the hidden key combination to enable the RGB output.