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Inside the Hayes Accura 288 Modem

First published: 21st December 2010

The Hayes Accura 288 Message Modem is a reliable device for fax and data calls, but does not work with vgetty for voice calls, in fact, it appears that most voice commands are simply not implemented. The modem was opened to investigate whether there was a removable firmware chip that could be upgraded with firmware from the very similar Accura 366 Message Modem.

Model Number5312HK

Opening the Case

Usually, there would be a disclaimer here pointing out that opening the case will probably void your warranty. As this modem has been out of production for many years, and the manufacturer no longer exists, this is irrelevant. However, any damage is your own problem.

The top and bottom of the case is held together by four clips, these can be reached through four small, rectangular holes in the base of the case. It should be possible to insert a thin blade into each of these, and release the clips with a little sideways pressure. A more likely result is breaking the clips, particularly as the case plastic is old and brittle from years of heat from the electronics inside. Either way, once the clips have been... released, the top of the case will lift easily away from the base.

The circuit board is held into the base by one screw in the middle, close to the speaker, and the two fixing studs on the D-25 socket at the rear of the case.


The identifiers of the significant chips are:

9611 A96975-6
Largest chip, square, surface-mountNear the front, left of the board
Two, identical rectangular DIL surface-mount chipsNear the front, right of the board
©INTEL 80,82
9605 .Z03457
Square, surface-mount chipBehind the two Winbond chips
Rectangular, surface-mount chip with paper label. The identifier beneath the label is not visible. Presumably the firmware.Near the right side of the board, next to the INTEL chip

It is obviously difficult to remove and replace the firmware, as it it surface-mounted. Whether it can be updated via the serial port is unknown.


modem circuit boardmodem circuit board hi-res

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