Rev F Configuration 4-3
4
➤ To test an H.E. power supply
1. Measure AC voltages at the MAIN FUSE and compare to the range shown in Table 4.2:
■ If the measurements are out of the acceptable range, take the appropriate
action shown in Table 4.3.
■ If the measurements are within the acceptable range, record the values on the
FlexNet® 700 Series Line Extender Data Sheet located in Appendix C.
2. Measure the B+, AC Ripple, and Reverse B+ (if applicable) and compare to the range shown
in Table 4.4:
■ If the measurements are out of the acceptable range, take the appropriate
action shown in Table 4.4.
■ If the measurements are within the acceptable range, record the values on the
Amplifier Data Sheet located in Appendix C.
Ta b le 4 . 3 AC Te st poi nt s
Testp oi n t
1
1. Attach the ground lead to the line extender housing.
Test Va lu e s Troubleshooting when Unacceptable
PORT 1 Centerseizure Screw
2
2. Test in outage situations only.
See Table 4.2 Verify that the center conductor pin and power cable are not
shorted to ground.
Check the tightness of the centerseizure screw.
Check cable plant powering.
MAIN FUSE or THRU
POWER FUSE
3
inputs
(left fuseclip)
3. Not applicable to units with a 117V
AC linear power supply.
See Table 4.2 If power is acceptable at the centerseizure screw, but
unacceptable at the fuse inputs, replace the RF module.
MAIN FUSE or THRU
POWER FUSE
2
outputs
(right fuseclip)
See Table 4.2 If power is present at a fuse input, but not at the output,
check for a blown or misaligned fuse. Replace or reinsert the
fuse. If the fuse blows when reinserted, check the
distribution system for short circuits.
PORT 3 Centerseizure Screw
(if thru powering)
See Table 4.2 If power is acceptable at the THRU POWER FUSE output,
but unacceptable at the Port 3 centerseizure screw, replace
the RF module.
Ta b l e 4 .4 DC Te st po i n ts an d Tes t Va l u e s
Testp oi n t
1
1. Attach the ground lead to the line extender housing.
Power
Supply
Acceptable Range Troubleshooting when Unacceptable
RAW DC
T.P
.
Linear P.S.
Only
28 - 35V
DC Adjust the Raw DC selector switch.
Replace the RF module.
B+ T.P. Linear P.S. 22.8 - 25.2VDC Replace the RF module.
H.E.P.S. 23.5 - 24.5V
DC Replace the power supply.
REV B+ T.P.Linear P.S.
Only
22.8 - 25.2VDC Replace the RF module.
B+ T.P.
(AC Ripple)
Linear P.S. < 20 mV
AC Replace the RF module.
H.E.P.S. < 15mV
AC Replace the power supply.
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