Epson

CX21 Ebay Listing

Models

Repairs, restorations & upgrades

October 3, 2026 · Repair

Fixing battery damage on main board

The device I bought from eBay had its battery removed but unfortunately too late. The battery leaked through the wires, through the connector to the pcb underneath.I tried to unsolder and replace the connector but the old connector came out together with the hole plating. The two images show CN3 after the failed attempt to…

Epson CX-21 ACM-21 board, component side

October 3, 2026 · Repair

Epson CX-21 acoustic coupler: reverse-engineering notes

No manual or schematic for Epson’s CX-21 acoustic coupler seems to exist online, so I traced the board, measured it and got it working. Chips, power system, the low-battery latch, testing without a phone line, and V.21 frequencies.

Photos