27
Subject to change without notice
3-2.12
Locate and identify the connector J2003 on YP board.
Short the outer leads of the 3 pole ribbon cable, so that the
symmetrical Y fi nal amplifi er gets the same input voltage
and current.
If the trace is visible, continue with item 3-2.13.
If the trace is still not visible, continue with item 3-2.14.
See photo 3-2.12.
Instead of shorting the
outer leads it is also pos-
sible to press the con-
nector and pull the ribbon
cable (out); without any
connection. If the Y fi nal
amplifi er is OK the trace
will become visible but not
focused as the medium
plate voltages are wrong
(approx. +146 V instead of
+85 V) causing a wrong crt
operating point.
3-2.13
Replace the YP board as described in the section Board
Replacement.
3-2.14
Replace the XY board as described in the section Board
Replacement.
If the trace is not visible, continue with item 3-2.15.
3-2.15
Replace the CC board as described in the section Board
Replacement.
3-2.16
Locate and identify the connector J2003 on YP board.
Press the connector and pull the 4 pole ribbon cable (out).
– If the trace is visible, continue with item 3-2.17.
– If the trace is not visible continue with item 3-2.18.
3-2.17
Replace the TB board as described in the section Board
Replacement.
3-2.18
Replace the CR board as described in the
section Board Replacement.
3-2.19
Locate and identify connector P4005 on TB board.
3-2.20
Measure the sawtooth signal (AS_X) using an oscilloscope
with a *10 probe at pin 5 of P4005.
If the signal is present, continue with item 3-2.21.
If the signal is not present, continue with item 3-2.22.
Photo 3-2.20.1
Photo 3-2.20.2
3-2.21
Replace the TB board as described in the section Board
Replacement.
3-2.23
Replace the XY board as described in the section Board
Replacement.
3-2.23
Replace the crt and make a complete new adjustment of the
oscilloscope as described in the Adjustment Procedure.
H M 3 0 3 - 6 T r o u b l e s h o o t i n g
Item
Behavior of the Instrument
Possible Reason / What to do
Remark
photo 3-2.12
photo 3-2.20.1
photo 3-2.20.2
