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The Memotech MTX Series

Memotech Hardware Repairs


This page provides details of some hardware fault finding and repairs on mine, and other's, Memotech computers. This page discusses some of the more serious problems that can occur with the MTX, your problem may be much more straightforward. You might like to take a look at this page too.

I hope you find the pages useful, of course, whilst the symptoms of a fault with your MTX may look similar to one, or more, of the faults listed here, there is no guarantee that the "fixes" described here will work for you.

The topics here are based on actual experiences for fault finding and repair of Memotech MTX computers, but before you start, you really should download a copy of the Memotech MTX500/512 Service Manual from my Manuals page.

Component Data Sheets - A selection of datasheets for components used on various Memotech boards


Getting access to the internals of Memotech hardware can be a little awkward, these notes may help :


Repair Procedures

MTX Computer Board

System RAM - Replacing the On-board RAM

System RAM - Using Andy's Replacement Memory Card

System ROMs

Video RAM


MTX Overheating Resistor - One MTX Power Problem

Black Screen, No Tone - Clock failure, and other, unrelated issues, including a sound problem

Black Screen, With Constant Tone - Bad ROM contacts and unrelated keyboard problem

PAL Video Board Problem - "Rolling" screen with "odd" colours

Sound Problem - Constant Tone from an otherwise working system

MTX Electrolytic Capacitor Replacement - In pictures (Photos from David Kimberlin-Wyer)


MTX Keyboard

MTX Keyboard Problems - Some common and not so common problems

MTX Keyboard Problem - Spurious key detection


MTX Speculator

Repairing my Speculator - hopefully! - ongoing


FDX Disc System

FDX Power Supply Repair - One Common FDX PSU Problem

FDX Power Supply Replacement - Using a PC PSU (Just an example, more complicated than needed)

My FDX System Fault Finding & Repair - A bit of a saga, but it came good in the end!

FDX Colour Display Problem - Incorrect Colour Display


Video Wall System

DDFS Power Supply - Failed - ongoing


Spare Parts

The Memotech MTX is now over 30 years old and many of its components are obsolete, it is still possible to obtain most components but they seem to be getting more expensive as they become rarer. I have a very limited quantity of a few components available should you be interested in sourcing them from the UK at, what I believe to be, reasonable prices

See here for details



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