HP82240B Internal view.

 

The HP82240B thermal printer can be opened by removing 6 screws. Four screws can be accessed by removing the rubber feet. The two other screws are located in the battery compartment. Take care, remove the print paper before opening the printer.

Picture of the HP82240B with removed top cover.

The printer module used, is build by Seiko, model MTP201-166. A single chip microcontroller of the OKI M80C50 series (HP part number 1820-6519) controls the printer. The received infrared signal is amplified and filtered by a KA2183.

 

The two pictures above show the PCB from both sides. On the left picture two more ICs are visible, which were hidden by the printer module on the top picture. These are the LB1246 printer driver and a MAX4193 DCDC Boost converter.

From this PCB a schematic view has been extracted. This schematic can be downloaded here.

 

HP82240B internal related links:

• Schematic HP82240A by Tony Duell