Service manual

The under side of the MTX reveals a single screw

which secures the MTX mother board to the bottom

chassis. By removing the main screw and earth strap

the MTX Mother Board and Rear Plug panel will

slide from the case bottom.

Faults are rarely complained about but nonetheless

faults, include I/O ports that are insecurely soldered

or not 'flush' with the main P.C.B. i.e. Power Supply

socket, Printer port, cassette ear and mic and joy

stick ports.

Any competent initial check of a returned MTX should

include these ports. It should also include checking

for the nylon washers on the solder side of the board

(esp under the tip 2955 power transistor and the

joystick port sockets ) which stops RE/CPM shorting to

earth - see Page 48 of assembly instructions of Power

Transistor.

Also check power supply voltage....ideally about 22.5v

to 24.5v and check to see that c56 and c51 - 4700 uf

16v capacitors are secure.

MTX Service Manual