Troubleshooting - Radio Shack TRS-80 Service Manual

5-2.
Troubleshooting
TROUBLE
CHECK POINT
SOLUTION
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SAVE impossible
Open circuit of jack cable. Replace jack cable.
Check the LSI terminal signals. If signals are normal, replace
the LSI.
-
Head of the cassette tape. Clean the head.
- - _
...
_ -
- - - - - _ . _ - - -
LOAD impossible Output level of tape recorder. Turn the volume control to max.
Check to see if there is an open
Replace jack cable.
circuit in jack cable.
---_.
Does the tape recorder function
Test the cassette recorder with
properly?
a tape of music.
Clock pulse. Replace crystal oscillator.
Signal C3 of the LSI. Shaping circuit.
If C3 is normal, replace the LSI.
Remote control Click sound of the relay at If click cannot be heard, check
impossible saving or loading.
signal C1 of the LSI.
If signal C1 is not output from
the LSI, replace the LSI.
If C1 is normal, remote control
circuit may be faulty.
Check to see if there is no open
Replace jack cable.
circuit in jack cable.
Clock pulse.
Crystal oscillator.
No function at all
Is PC-4 properly
Connect correctly.
connected?
- - - - - -
Poor contact of connector.
Replace connector.
Clock pulse.
Crystal oscillator.
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