Service manual

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NB: We find it helpful to replace all the socketed
IC's with a known good set before attempting to
rectify this fault.
* The fact that a signal is absent from the system
data bus does not necessarily mean that there
is a fault in Ram. It is very difficult to
determine Ram faults with an oscilloscope alone.
You really do need the Memotech Ram Rig Tester.
SYMPTOM 6
Problems with the load and saving functions
a)
Cause of Trouble
Faulty jack socket
Check Point
J2 Ear jack socket
Repair Method
1 Jack socket J2 may be loose or worn, also buzz
across the socket is 0v - CSTT out - to check
for shorts - replace socket.
b)
Cause of Trouble
Faulty IC BCN4070 CMOS or associated circuitry
MTX Service Manual