WG6100 HV Low

Talon2000

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Have a 6100 that had a bad fly. replaced it, capped, and put new transistors etc. But I'm not able to get the HV past 14kv. Or if measuring on pin 5 of J900 125VDC The adjustment is very limited, say from 12.9kv-14kv

Tried replacing ZD902 again, no help.

Ideas?
 
Did you replace the adjustment pot? Of did your kit come with one?
Also a common mistake made on the K6100 is people use the ZD902 part for D902 and vice versa.
 
From the 6100 faq:

Low HV assuming the zenner is ok:


· R915 (open)
· R922 (open or wrong value)
· Q900 (emitter pin open)
· Q902 (bad)
· Q906; white and black leads reversed (scope pattern is wrong)
· ZD901 (shorted)
· IC901; if scope output is a little high, replace IC901
· P900 (ribbon pin #7 broken)

Symptom: HV Range Wrong, What Causes It?
Normal HV range is between 16-24 kV
HV Voltage Range Look at
??.?-12.0 kV Q902 (reversed)
7.0-10.0 kV ZD902 (bad)
7.0-17.0 kV ZD902 (bad)
7.0-22.0 kV Q903 (bad)
9.0-18.0 kV ZD902 (bad)
11.0-22.0 kV ZD902 (bad)
15.0-18.0 kV ZD901 (wrong value)
16.0-19.0 kV ZD902 (bad)
18.0-27.0 kV ZD902 (bad)
19.0-27.0 kV R912 (wrong value)
21.7-30.5 kV C916 (open)
28.0-20.0 kV C916 (bad)
 
I've personally seen both the resistors bad, and at least one of the transistors bad on monitors I've fixed. -Malcolm
 
· R915 (open) Good 1000 ohm
· R922 (open or wrong value) Good 1107 ohm
· Q900 (emitter pin open) Good / replaced with known good as well
· Q902 (bad) Good / replaced with new
· Q906; white and black leads reversed (scope pattern is wrong) Good/replaced with known good
· ZD901 (shorted) Good/replaced with new, and known good
· IC901; if scope output is a little high, replace IC901 Good/replaced with known good
· P900 (ribbon pin #7 broken) Good

Also replaced R918 with a new pot (came with the kit)
Reflowed all solder joints, and have checked for bad traces.

So I guess it's down to shotgunning it with my known good HV unit

hmm.
 
· R915 (open) Good 1000 ohm
· R922 (open or wrong value) Good 1107 ohm
· Q900 (emitter pin open) Good / replaced with known good as well
· Q902 (bad) Good / replaced with new
· Q906; white and black leads reversed (scope pattern is wrong) Good/replaced with known good
· ZD901 (shorted) Good/replaced with new, and known good
· IC901; if scope output is a little high, replace IC901 Good/replaced with known good
· P900 (ribbon pin #7 broken) Good

Also replaced R918 with a new pot (came with the kit)
Reflowed all solder joints, and have checked for bad traces.

So I guess it's down to shotgunning it with my known good HV unit

hmm.

Have you verified that the low voltage going to the HV cage is correct? I doubt that is it since your range is so limited, but since it is low it doesn't hurt to test it real quick.

-VJ
 
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