19 inch B&W Motorola Horizontal Collapse

Phetishboy

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Well, finally got my cap kit and other parts over the weekend. Capped the monitor, put it back together, tried to power it up, it blows my GFI outlet every time. Not sure if I've got a solder bridge somewhere or what, but this chassis is a bitch to take apart so it may take me a while to get up enough willpower to pull it apart again just to check.

Also, between the width coil and the width cap, there is a large section of the board that is scorched. In fact, there is a hole right through it. Now this obviously happened long ago, and the monitor was powering up before I capped it, but could this have anything to do with it blowing the breaker? And a follow-up question, should I be adding a jumper wire between the coil and the cap, as right now there is a hole there, or were they never connected via a trace?
 
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Little update. Monitor powers up now but still is just a thin line down the middle. Vertical collapse?
 

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can we see pictures of the burnt spot on the board ? yoke & all that junk

is this what the display originally looked like before the cap kit?
 
well the new caps at least increased the brightness factor, what model is this beast?

monitor orientation being what it is (confusing), i believe thats actually horizontal collapse - nothing is seen horizontally, you have the vertical being displayed as shown

anyway, need the schematics for it
 
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Make sure the horizontal winding of the yoke isn't open. Next trace the yoke back through the width circuit to the collector of the HOT. More often than not it's just a bad connection.

I have a few Motorola service manuals. Let me know a model number and I'll see if I have the one you need.
 
Sounds good. Then I assume this huge scorch in the width coil area might have something to do with this?
 
Sounds good. Then I assume this huge scorch in the width coil area might have something to do with this?

They do get hot and discolor but on most of them the width coil is on the yoke feed so if there is frosty connections it could cause your lack of deflection. A picture of the solder side of the board will help.
 
They do get hot and discolor but on most of them the width coil is on the yoke feed so if there is frosty connections it could cause your lack of deflection. A picture of the solder side of the board will help.

Will do, but I warn you, you're not gonna like it.
 
Here are some pics:

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And here are pics of the auxiliary board and where it connects to the mainboard. Do I need to replace that big orange cap? Does anyone know which 73V pin I should be connecting to on the main chassis? Or doesn't it matter? What does upping the 73V pot do?

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Have you ohmed the width coil? You should get some kind of resistance there.

If it's completely open (or disconnected), you won't get any horizontal width at all. That's your symptom, I believe.

Width coil should have two posts, put your meter on ohm setting and see if you can get a mesaurement.

Someone else here have a non-crispy chassis they can examine to make sure Phet's coil is connected to the right traces?
 
Have you ohmed the width coil? You should get some kind of resistance there.

If it's completely open (or disconnected), you won't get any horizontal width at all. That's your symptom, I believe.

Width coil should have two posts, put your meter on ohm setting and see if you can get a mesaurement.

I've got 5 ohm settings. Which one?
 
I've seen worse. It looks like it's an M5000 chassis. The width coil could be open or a trace burned. Measure the impedance between the two shown test points but my guess is you'll probably have to remove the two coils, clean and rebuild the traces.
 

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Yeah I'm not getting anything between those 2 pins. I assume I need to run a jumper from the 2 spots on either side of the burn hole.
 
judging by your pics i can see the trace is broken and pulled up slightly at the H-coil so that will definitely need to be repaired
at least it appears that way

do a continuance test on both of those crispy pins to see if either is actually connected - you can compare with schematic bit attached above
 
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judging by your pics i can see the trace is broken and pulled up slightly at the H-coil so that will definitely need to be repaired
at least it appears that way

What he said. Yellow arrow points to what appears to be a lifted trace.



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What he said. Yellow arrow points to what appears to be a lifted trace.



attachment.php

Yeah, I saw that before Kenny posted it, but I need to know how many jumpers I need and what I am jumping. Looks like I need to jump the 2 large solder blobs together and jump the broken trace? Anything else?
 
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