Tandy 1400LT - Internal FDD Troubleshooting

@ Internal FDD Troubleshooting
Is Boot select switch
Has the located diskette
been properly initialized?
I
Check the connectors and
cable connected
to the FDD.
Check the power supply
of FDD (t5V)
Check ”FD POWER CON” signal.
TR16: Base
The level
of ”RESET765” signal
when
FDC is turned on
Pin53
of GATE5 should be low level.
c3
Check the frequency
at Pin3 of IC57.
It must be 4MHz.
of GATE3
and TR16
TR17: Base
Check L3,
C62,R53 and
C63
5-16