Toshiba T4400 C / SX Repair Notes

by Bryan A. Thompson

Created 12/1998

 

This is the older style case with the case split at the keyboard.  This has a ZIF socket, and contains a standard 486 SX or DX processor, and has sufficient clearance with the protective metal shield removed, so it can be upgraded to a 50, 75, 100, 120 or 133 with a 5V overdrive chip (Intel, AMD, Evergreen, etc) or with a 3.3V overdrive with a regulator mounted between the CPU and motherboard.

 

 

Hard drive upgrades -

This is a very involved upgrade requiring a thorough disassembly (1+ hrs). 

Hard drive settings are done through the BIOS (or a utility called Test3.exe, available on the Toshiba website).  It sees either a 120 or 200MB, as these were the only ones available through toshiba.  If a larger hard drive is used, the BIOS reports this as a setting error and enters setup, asking the user to correctly set the hard drive type.  A drive overlay will not solve the problem as the unit never boots with the larger hard drive installed.

 

No PCMCIA ports on these - The RAM expansion is a proprietary RAM port, and PCMCIA cards cannot be used. 

 

Onboard RAM: 4MB.  RAM expandable to 20MB with the 16MB (largest avail.) expansion card installed.

 

The 4400C contains an active matrix screen, but it’s very dim while displaying a DOS / Text screen, almost to the point of being unreadable.  This isn’t a problem when in Windows, and doesn’t necessarily indicate the unit has a backlight problem.   Viewed from an acute angle, the backlight should be visible.  There are no brightness or contrast adjustments on this unit.

 

 

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