G05-802 half screen *Solved*

drewscruis

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Working on a monitor for a friend, I recapped it and replaced the chassis transistors. After the cap kit and chassis transistors checks, I checked the fuses before I apply power. I found F102 open, My question is what else should I check before applying power and is this supposed to be a fast blow fuse or a slow blow fuse? what was in there was a fast blow. And should F100 and F102 be slow blow or fast blow?

Fixed the neck glow issue by replacing and repinning p500.
 
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Working on a monitor for a friend, I recapped it and replaced the chassis transistors. After the cap kit and chassis transistors checks, I checked the fuses before I apply power. I found F102 open, My question is what else should I check before applying power and is this supposed to be a fast blow fuse or a slow blow fuse? what was in there was a fast blow. And should F100 and F102 be slow blow or fast blow?

f100,101 and 102 are slow blow fuses
 
as security said, they need to be slow blows.

I would check that Q900 and Q903 aren't shorted. Probably should do a run down on all the transistors and diodes on the HV board. Make sure nothing is shorted out (you can do this completely in circuit)

But its possible F102 blew because it was the wrong fuse.
 
Ok, I fixed the fuse problem. but I have no neck glow. I checked on another monitor and there is neck glow on it. but when I plug this one back in there is nothing. Any ideas? I can hear chatter like the flyback is powered up when its turned on.
 
is the 6.3v a pass through connection, or is there any circuitry to the filament voltage? I'll look further into it tomorrow.
 
Ok got the neck glow sorted out. Still not 100% why it didn't work, but I replaced the P500 header and repinned the connector. I also cut and soldered the 2 connectors for the neck heater on the deflection board (the ones from the main connector input to the monitor). I kinda goofed tho. I forgot to plug in the yoke and when I powered it up. I did see/hear a tiny spark, thought it was the fuse for the fram mount transistors but that is good. I have an image now, but only half. See pic
ba4d586e403f603cac7b5023e6e4e6e6.jpg


Also is there a map/pic of the frame transistors anywhere?
 
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my problem too

Ok got the neck glow sorted out. Still not 100% why it didn't work, but I replaced the P500 header and repinned the connector. I also cut and soldered the 2 connectors for the neck heater on the deflection board (the ones from the main connector input to the monitor). I kinda goofed tho. I forgot to plug in the yoke and when I powered it up. I did see/hear a tiny spark, thought it was the fuse for the fram mount transistors but that is good. I have an image now, but only half. See pic
ba4d586e403f603cac7b5023e6e4e6e6.jpg


Also is there a map/pic of the frame transistors anywhere?



i have the exact same issue, except left half of screen is collapsed! i have been told it is the frame mounted transistors that we need to check!
 
ok for shitts and giggles I swapped the transistor pairs and nothing on the screen changed. you would think by switching them that the other side of the screen would have gone dark and the dark side would have lit up. so pretty convinced this isn't a chassis transistor prob.
 
weird

ok for shitts and giggles I swapped the transistor pairs and nothing on the screen changed. you would think by switching them that the other side of the screen would have gone dark and the dark side would have lit up. so pretty convinced this isn't a chassis transistor prob.

well dang it - u would think that would have switched sides ?
hopefully some more of the experts on here will give advice!
 
transistor sockets are all new. fresh solder and checked for continuity back the the header of the deflection board
 
The connectors are all crimp style. There are no idc connectors. I checked all the chassis transistors and they measure within spec.
 
if you're 100% confident in your previous work i'd check Q706, Q707, and R720.

also, since you didn't explicitly say you did this: reflow your header joints. don't simply inspect them visually, remove old solder and add fresh. even though you tested continuity between the transistor and the header, it might not be a solid, lasting connection.
 
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ok this weekend I am going to replace the last remaining headers and repin the connectors for the chassis transistors and the yoke. the headers were reflowed, but not by me.
 
Felt ambitious when I got home from work. I replaced the 3 header's ( 2 xy transistor ones and yoke one) and repinned the 3 connectors. No change, still displays half screen. Will pull the deflection board tomorrow and check the transistors suggested above.
 
if you're 100% confident in your previous work i'd check Q706, Q707, and R720.

also, since you didn't explicitly say you did this: reflow your header joints. don't simply inspect them visually, remove old solder and add fresh. even though you tested continuity between the transistor and the header, it might not be a solid, lasting connection.

ok, i checked the 3 components you mentioned, and there within spec.
 
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