19k7000 - vertical collapse / high b+

87 t-66

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I am working on repairing a 19k7000 that showed no picture when I got it and had no neck glow. The HOT was bad. After replacing the HOT I could only get it to turn on by lifting D10. I replaced IC4 with one that is known good and now it will turn on with D10 in place, but the B+ is around 160v DC and there is only a horizontal line across the screen about 2 inches thick. When I turn it off, for the split second that it shuts down there is full deflection but is in vertical collapse otherwise. The chassis has been re-capped. I have looked over it for broken traces and cold solder. Any suggestions on how to proceed would be great. Thank you.
 
You very likely have two separate problems there.
Check your yoke resistances first, just to rule out a yoke coil problem (very rare, but happens sometime).
Check resistors on the vertical deflection circuit.
Check all the components on your power supply circuit starting from transistor in the voltage regulation area.
Your flyback is good being that you have a pic (even if defective)
 
the yoke readings are good...will troubleshoot more tonight. any other suggestions are appreciated
 
check your yoke traces. boneheaded as it sounds, I had a chassis in horizontal collapse and unless you squint your eyes very tight and look very close, you would never know that solder pad was broken clean off from the trace.

for shits and giggles measure R101, in circuit. it's supposed to be like 6.8k ohm. I have about 3 chassis at the shop where there's something in the circuit pulling that resistor down. I know people clamor about measuring out of circuit, but that's not the point here. that said, those all have B+ 160+, either it runs hot for awhile or it bounces the shutdown immediately and never turns on.
 
check your yoke traces. boneheaded as it sounds, I had a chassis in horizontal collapse and unless you squint your eyes very tight and look very close, you would never know that solder pad was broken clean off from the trace.

I had this very thing happen also. Worked on a board on/off for a month. Replaced broken components/flyback/Hot's/etc , reflowed everything, and couldn't fix it. Left it on the shelf for a while. Picked it up one day and noticed a slightly off color pad. Looked at it through the magnifying glass and sure enough no pad!. LOL
Soldered a jumper and it worked perfect. Lesson learned. Look for missing pads!
 
I went over the yoke traces and reflowed them yesterday but will check again this afternoon.
 
Well today it doesn't seem to want to turn on at all. I am getting 148v b+ at r301 near the tube but no neck glow. I pulled d10 and it didn't make a difference. R101 tests good
 
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when you figure out your HV shutdown check your voltage at the vertical IC.

check for cold solder joints for your HV shutdown.

wipe your HV shutdown pot a couple times to see if it has a dead spot.
or just replace it.

if you hit a brick wall, your welcome to send it in.

Peace
Buffett
 
#1.) Lack of B+ regulation.
having horizontal scan and a bad b+ if you know your regulator is good would be unusual since the regulators have a fixed output.

did you forget the regulator insulator? are you sure your not reading the wrong side of the 15watt resistor and the shutdown trigger being a different fault? known good regulator is no longer good?

#2.) Lack of vertical deflection can be a host of problems but look to see if R92 may be open.
 
the regulator insulator is there. i was reading the side of the large resistor near the tube. the other side is only a few volts difference IIRC. (i am talking about the large resistor on the side of the chassis with a blue and red wire going to it.) i will check r92.
 
Just tried another regulator for the hell of it. Still no neck glow. I can't find any open/shorted resistors or diodes in the area or solder issues. Looks like this chassis is going back in the parts pile.
 
No but maybe they can be used to fix another one. It also doesn't cost me anything lol. I'll respond to your pm in a little bit. Thanks
 
No but maybe they can be used to fix another one. It also doesn't cost me anything lol. I'll respond to your pm in a little bit. Thanks


coming back to it later also can help put a new perspective on it.
 
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