K7000 Foldover Issue

Esom

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I have this K7000 that aaaaaaaalmost works after needing quite a bit of work.

I replaced IC2 and IC3, all new caps, checked ratings for all resistors in the vertical and horizontal circuit, adjusted 50/60hz pot, H-hold, V-Size, etc. and this is as close as I can get it.

Hard to tell from this image, but the top 3" or so has folded over, is upside-down, and creates an interference pattern anywhere it intersects with any other image being displayed.

I have sync on pin 10.

Any suggestions?
 
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Going from component to component I've been just checking the item and referencing the schematic. I passed over R83 (680 ohm) and when I tested it it read half that (330 ohm). I went to desolder it, just to check its value out of circuit, and found another resistor with the same rating soldered to the underside of the chassis. Is this supposed to be here? Why would two identical resistors be soldered in parallel? Is this possibly the culprit?
 

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Going from component to component I've been just checking the item and referencing the schematic. I passed over R83 (680 ohm) and when I tested it it read half that (330 ohm). I went to desolder it, just to check its value out of circuit, and found another resistor with the same rating soldered to the underside of the chassis. Is this supposed to be here? Why would two identical resistors be soldered in parallel? Is this possibly the culprit?
that's how Wells-Gardner made it. the K7000 had many changes over time. you don't ever want to undo factory mods.

was this a tube swap that's running a TV yoke? a lot of people just measure resistance on yokes and go "oh it's close enough!" and it really isn't. we got monitors in where I work years ago that had blown out width or height and it's because they were TV yokes that didn't work right.

why did you replace IC2 and IC3? was your vertical IC replacement the same part number you replaced? this is another area people goof up with monitors, especially the inexperienced ones because they read things, and wind up changing a lot of parts that shouldn't be changed. when you have problems in the aftermath it becomes difficult to track backwards and find what's wrong. if you didn't use the same vertical IC part then that's probably why it's overdriving the height.
 
Okie dokie!

No, origional tube and chassis to this Dynamo, as far as I can tell.

I changed them because thats what the manual said might work given my original issues. It did fix the problems.... mostly.

Anywho, JUST got it working! I inadvertently desoldered one of the traces from IC3 not realizing it went in two directions, unlike all the rest of the pins.

S'working now!
 

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Okie dokie!

No, origional tube and chassis to this Dynamo, as far as I can tell.

I changed them because thats what the manual said might work given my original issues. It did fix the problems.... mostly.

Anywho, JUST got it working! I inadvertently desoldered one of the traces from IC3 not realizing it went in two directions, unlike all the rest of the pins.

S'working now!
user error is probably one of the leading causes for problems of all kinds

ask me how I know. LOL

good job
 
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