Tandy 1400LT - External FDD Troubleshooting

@ External
FDD Troubleshooting
Is boot select switch
Has the located diskette
been properly initialized?
Check the
connectors and
cable connected
to the FDD.
0
I
I ---
Check the level of "RESET765" signal
when FDC is turned on
Pin53 of GATES. It
should be Low.
IES Check
Check the frequency
at Pin3 of IC57.
It must be 4MHz.
1
Check CTL6, C91,
and C92.
(The frequency is 16MHz)
5-28