K6100 rebuild no HV

Deadly

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Prior knowledge of this monitors condition unknown .... was brought to me dead. Zanen get well kit installed in it's entirety. The spot killer LED comes on now.
HV readings of of R900 are +25 and -25. Pin 5 off HV header reads +25. All surface mount transistors check out ok.

If I unplug P100 the spot killer LED goes off. Both transistors it's connected to check out fine.

Turning brightness up all the way - no spot on screen

Nothing was installed backwards. Inspection shows no solder bridges either.

Ideas?
 
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Check the B+. It's supposed to be measured at pin 5 of P900, but it is kind of difficult to get your lead in there sometimes, so just follow that orange wire to where it connects to the neckboard and measure it there. It should be +180vdc...
 
Had a few minutes to look at it this morning.
The orange wire at the neckboard - 25VDC
I used my DMM to check the transistor located under the defection board and it rang open. Shit.... I grabbed another one with a new mica insululator, slapped on some silicone grease and mounted it back up. Ensured not grounded out via continuity test - fired up and LED is on. Shut off and checked transistor - it's ringing open again?

And I also replaced another surface mount transistor (continuity test on old one produced a quick "BIP") and the same damn thing - tests fine, fire up and then test and it rings open. ???????

The first thing that comes to mind is I'm grounding the transistor out against the frame - but after a fresh install with new mica insulator I check and it doesn't ring open ... could a component on the deflection board cause this?

Also I should mention I do have neck glow and the fuses don;t blow.
 
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I'm guessing that in your vernacular "ring open" means "shorted"? So, "doesn't ring open" means you have no continuity? Normally, open means no continuity and closed or shorted means continuity, so I would expect "not open" to mean it is shorted.

Either way, you should NOT have continuity between the outside casing and the frame. Bear in mind that this is with the connector on the deflection board disconnected, as you may get false readings through the board...
 
Doh .............. I didn't even think about a false positive form having the deflection board connected.

And yes, ringing open was poorly worded - shorted is what I truly meant. ;)

Thanks Mod - I'll check it out futher when I get home tonight.
 
I waited until Spaeths LV6100 came in which showed up a little while ago. I now have that installed.
Deflection LED came on. Found the monitors input molex connector has a lazy pin. Now deflection LED stays off - LV6100 LEDS stay solid red.

Unplugged connectors for the surface mount transistors and tested them. No shorts. I tested them connected. Oddly enough transistors for P100 meansure +33 and -30VDC.
All the others test ~ +&-22VDC.

Doesn't blow fuses. Has neck glow and still no 180+.

I decided to focus on the HV at this point. I found the resistor at R913 deader than a door nail. I don't have the part to replace. Will update when I receive next week.
 
Replace faulty resistor and I still have no HV. I've tested the BU406 which tests good. I'm not quite sure where else to look at this point. :(

Recap:
Zanen get well kit installed
Solder reflowed where necessary
All surface mount transistors have been replaced and test good
LV6100 installed
Spot killer LED is off
Both LV6100 LEDS are lit.
Deflection chatter and neck glow is present.
Have = + and - 25 on P900 connector pins
B+ registers ~21 on pin5 of P900
Any one have any ideas?
 
I'm guessing you rebuilt the HV section with all new caps and HV pot?

Wires in good on the back of the focus and brightness pots?

Change out the diodes in the HV section? Or the transistor mounted on the outside (might the the BU406 I'm thinking of)?
 
I'm guessing you rebuilt the HV section with all new caps and HV pot?

Wires in good on the back of the focus and brightness pots?

Change out the diodes in the HV section? Or the transistor mounted on the outside (might the the BU406 I'm thinking of)?

Rebuilt HV with new caps and HV pot
Checked wires on flyback - both solid
Have not changed out all diodes on the HV board. Only what came with the rebuild kit.

Yes BU406 is on the outside (backside next to focus and brightness)

I guess if we're all in agreement the issue is on the HV board then I'll guess I'll start by changing out the diodes in the HV section that weren't included in the Zanen get well kit.
 
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I had a similar scenario with a 6100 once that turned out to be a broken leg on a resistor. While poking around on the high voltage board, one resistor that appeared to be connected but when wiggled was very loose had the leg severed from the board.
 
I hate it when people don't post their results. Anyways I got tired of looking at this monitor (sore reminder heh) and after pulling everything and testing the only things I was unable to test was the flyback and 555 timer. I shot gunned a 555 timer in and boy I have never been so glad to hear the jarring sound of HV. Used my HV probe and she's bright and solid.

Thanks to everyone for their insight - especially Mod, you are the next Ken Layton heh.
 
I hate it when people don't post their results. Anyways I got tired of looking at this monitor (sore reminder heh) and after pulling everything and testing the only things I was unable to test was the flyback and 555 timer. I shot gunned a 555 timer in and boy I have never been so glad to hear the jarring sound of HV. Used my HV probe and she's bright and solid.

Thanks to everyone for their insight - especially Mod, you are the next Ken Layton heh.

What is a 555 timer? My 6100 is still down with low B+, 71vdc. Could this be my issue as well?
 
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