Figure 4-18: Troubleshooting Procedure (3) - Tektronix MTX100A Service Manual

Troubleshooting
(A)
Is +5 VSB line at pin 9
of J170* on the A20 PCI
Backplane board correct
(4.9 V to 5.30 V)?
When the ON/STBY
switch is pressed, is the
voltage at pin 10 of J240*
about 5 V?
Is PWON# line at pin 10
of J170 on the A20 PCI
Backplane board about
0 V ?
Are all the voltages of
+5 V, +3.3 V, +12 V, and
- - 12 V correct ?
Replace the CPU board.

Figure 4-18: Troubleshooting procedure (3)

4-40
No
* See Figure 4-23 on page 4-44.
Yes
No
* See Figure 4-24 on page 4-45.
Yes
No
Yes
No
Yes
H Check the cable 174-5172-00.
H Check the 5 V main power supply
module on the A40 AC Distributer
board.
H Check the 174-5185-00, 174-5220-00,
and 174-5173-00 cables.
H Check the ON/STBY switch on the
A35 Power switch board.
H Check the 174-5174-00 cable.
H Replace the CPU board.
Remove the A12 Main board or the
optional interface module (if installed)
from the A20 PCI Backplane board.
2
MTX100A MPEG Recorder & Player Service Manual