D-Link DSL-2750B rev B1

Overview
"2976380401" and "A610A234006R_R6" is silkscreened on the board.
 * This device appears to use Broadcom BCM63281.

Additional models of.. D-Link
 * DSL-2750B (Annex A, USB, 'dying gasp' feature)
 * DSL-2740B (Annex A, no USB, without 'dying gasp')
 * DSL-2740U (Annex A, no USB, without 'dying gasp')
 * DSL-2741B (Annex B, USB, 'dying gasp' feature)
 * DSL-2741U (Annex B, USB, 'dying gasp' feature)

Links of Interest

 * Technical information for the D-Link DSL-2750B rev B1 on the OpenWRT forum

Flashing
Firmware can be flashed via the regular web interface, though if you have firmware v2.03 it sometimes uploads the firmware and then says "The selected file contains an illegal image".

In this case you can use the CFE bootloader: power the router off, hold the recessed reset button pressed with a pointy object, power the modem on and, within the first few seconds, navigate to 192.168.1.1. You should get a plain HTML page with nothing but "Browse" and "Upload firmware" buttons.

Serial Pinouts
The internal serial header on this device is J606, which is assumed to have the same pinout as the D-Link DSL-2750B rev T1: J606 (RxD) (GND) (TxD) (3.3) Pin4 Pin3  Pin2  Pin1  Pin 1 is the right-hand one when looking at the top of the circuit board from the front of the router (on the underside it has a square pad instead of a round one.)

This is untested.

Pictures
Retail Images