put(s) of the PDM generator are at fault by
connecting a voltmeter or oscilloscope to
R45, R46, R62, and R63. The faulty out-
put(s) will be as much as 14 volts positive
if read on a voltmeter, or continuously high
if observed on a scope (DC coupled). Refer
to Figue F-4.
F.3.4.
Symptom: Only One Output High
This is probably a fault of U9 or U10
depending on the output line in question.
F.3.5.
Symptom: Two Outputs Are High
If the signals at R45 and R62 are both
high, U1 most likely has failed. Check the
voltage at U1-14. Normally it is -2 volts or
less, but in this case it might be +2 volts or
greater.
F.3.6.
Symptom: All Four Outputs Are
High
Check the PDM Level reading on the Mul-
timeter. If it is excessively high (such as
pinned) the problem would be on the Con-
troller in the power level summing circuitry
U19.
If the PDM Level is okay, the problem
could be caused by U1, U2, U12 or U15 on
the PDM Generator. Check the voltage at
R17 pin 7. Normally it is +1 to +2 volts, but
in this case may be further negative.
Check the output of the audio input am-
plifier at U1 pin 8. This should be practi-
cally zero volts. If it is not, try replacing U1.
If no fault is found with U1, try replacing
U12.
U15 may be the cause of the problem if no
other is identified.
Figure F-2
Upper Trace - U4-2, 5Vp-p
Lower Trace - U4-12, 5Vp-p
Figure F-3
Upper Trace - U9-5, 3.5-4Vp-p
Lower Trace - U10-5, 3.5-4Vp-p
Figure F-4
Upper Trace - R63, right side, 13Vp-p
Lower Trace - R62, right side, 13Vp-p
Rev.AE: 03-05-2002
888-2314-001
F-3
WARNING: Disconnect primary power prior to servicing.
Содержание Gates Five 994 9204 002
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Страница 28: ...2 12 888 2314 001 Rev AC 2 29 00 WARNING Disconnect primary power prior to servicing...
Страница 40: ...Figure 5 1 PDM Flow Diagram 5 2 888 2314 001 Rev T Jan 1996 WARNING Disconnect primary power prior to servicing...
Страница 42: ...Figure 5 2 PDM Loop 5 4 888 2314 001 Rev T Jan 1996 WARNING Disconnect primary power prior to servicing...
Страница 43: ...Figure 5 3 RF Flow Rev T Jan 1996 888 2314 001 5 5 WARNING Disconnect primary power prior to servicing...
Страница 76: ...C 6 888 2314 001 Rev AE 03 05 2002 WARNING Disconnect primary power prior to servicing...
Страница 82: ...E 4 888 2314 001 Rev AE 03 05 2002 WARNING Disconnect primary power prior to servicing...
Страница 88: ...F 6 888 2314 001 Rev AE 03 05 2002 WARNING Disconnect primary power prior to servicing...
Страница 96: ...H 2 888 2314 001 Rev AA 8 18 1999 WARNING Disconnect primary power prior to servicing...
Страница 104: ...K 2 888 2314 001 Rev AE 03 05 2002 WARNING Disconnect primary power prior to servicing...
Страница 105: ...Figure K 1 Interface Board Rev AE 03 05 2002 888 2314 001 K 3 WARNING Disconnect primary power prior to servicing...
Страница 108: ...L 2 888 2314 001 WARNING Disconnect primary power prior to servicing...
