SOLVED! K7000 first recap attempt; of course I broke it…

I really appreciate all of the suggestions from everyone. And hey, we learn best when we're solving problems. I learned way more about the actual tube connections and the flyback functionality than I had any idea about a few days ago.

Next step: now to try swapping the tube with a TV I got from a neighbor! See @TheYeti, at least I knew to confirm chassis function on the original tube after the reconditioning before trying to swap tubes too!

Many lessons learned here!
 
I learned way more about the actual tube connections and the flyback functionality than I had any idea about a few days ago.
This is really the silver lining and I loved seeing your perseverance to solve the problem regardless of how easy the solution was.

I wish that I could have provided more technical assistance but there are far more intelligent members here anyway.

However, I was watching from the sidelines and learned some things myself.

This thread is a great example of "the journey is the reward". Sometimes struggling a little with a problem is a good thing and you learn so much more than just being provided the answer right at the beginning.

Although maybe you would have preferred that! LOL ;)

Great job sticking with it. :)
 
Thanks and totally agree! I've lurked here long enough to see that those that get the most help with troubleshooting are those that continue to try to work a problem and don't just sit back and wait for someone to tell them exactly what to do. That's not a bad thing, knowing it kept me trying to figure out next steps to at least test and update the thread, hoping it might trigger some more suggestions. Which it did! 👍

I'm a life long IT engineer/"computer guy." So game boards make reasonable sense to me. There's CPUs, RAM, ROMs, ancillary subsystems, I/O, program code… I can mostly understand that stuff at least at a high level. But CRTs just blow my mind given the (relatively) simple and discrete components and circuits which do something as mind-boggling as generating and steering electron beams with magnetic fields to create images on a substrate of excitable phosphor using simple voltages to make it all happen. Still trying to wrap my brain around that 100-year old tech!
 
Good job! Monitors are actually pretty easy to work on, and it's usually something simple like you found out. But you have to know how to work on them safely, and where to look!

If you want to post another thread about the tube swap, if you had any questions, we'd help you there too.

In fact I can start it here with some things to look for. Know what the tube number is (a 7ish digit number that usually starts with A and then a 48 or 51 (hopefully not lol) or a 63). Also, people would need to know the yoke resistance, and inductance if you can.
 
But if the ground trace on the neckboard (big spot with G1 and heater return line) was in fact disconnected from ground, it is unclear why you could read the heater voltage. Were you actually using that ground for the heater reading or some other point?
 
Good job! Monitors are actually pretty easy to work on, and it's usually something simple like you found out. But you have to know how to work on them safely, and where to look!

If you want to post another thread about the tube swap, if you had any questions, we'd help you there too.

In fact I can start it here with some things to look for. Know what the tube number is (a 7ish digit number that usually starts with A and then a 48 or 51 (hopefully not lol) or a 63). Also, people would need to know the yoke resistance, and inductance if you can.
Thanks! I may well start a thread for the swap. My donor tube is a A48LRH93X which I understand from other KLOV threads and that CRT swap database is likely (hopefully?) a drop-in replacement for the K7000. My DMM does inductance, so I will confirm readings between the old and new tubes. The yoke connector on the donor tube is a different plug style so I'm waiting on an order of yoke connectors from APAR to arrive tomorrow so I can swap the connector assuming the yoke is otherwise compatible. Hoping to get to this Sunday or Monday.

Happy Thanksgiving!
 
But if the ground trace on the neckboard (big spot with G1 and heater return line) was in fact disconnected from ground, it is unclear why you could read the heater voltage. Were you actually using that ground for the heater reading or some other point?
I took the reading from the solder point for CRT socket pin 5 and had the other side of my DMM clamped to the monitor frame — again assuming I had contiguous ground all the way to the frame, which was there the neckboard ground was connected. But once I moved the neckboard ground to the deflector board heatsink as mecha suggested, everything worked. I reinstalled the monitor and ran it for about 6 hours yesterday and it was perfect. No focus drift or issues with the image "blinking" out, both of which I was having before working on the chassis. Monitor seems to be 100% now.
 
This is bad? Of the dozens of posts I've seen over the years about people spraying chassis in driveways, dishwashers, etc., I've never heard you should remove the flyback first?
Agreed. If you are supposed to be removing the flyback before washing the chassis, then I've been doing it wrong for 10 years.
 
The weak part of the flyback in case of washing is the box with the screen and focus trimmers. This box is not filled with potting compound like the part that houses the windings. If water goes in it can alter or even completely impede the working of the trimmers. Not all flybacks are created equal. Some designs are particularly poor in this respect. In this type for instance you can see that water could easily flow in through the points where the wires come out. I've had a few of these where the picture couldn't be focused anymore after washing.

DSCN3151.JPG

Other flybacks are designed differently. This is a stock WG K7000 flyback. The wires come from the potted part which makes it safer than the previous type. But water can still enter through the knobs so I maintain the view that the flyback is one of those parts that should not be submerged in water.

flyback d.JPG

And it's not the only one. Open windings can entrap water inside for a long time even if it looks dry on the outside. Even if it works fine immediately, it may cause damage later. The transformer in the PSU of a K7400 and similar is of this kind and even the small horizontal drive transformers on most chassis. And the deflection yoke of course. Dual PTCs that are enclosed in a box (i.e. the type on a K7400 but not the mono one on the K7000), CRT sockets. These parts should be desoldered and cleaned separately especially if it's an obscure monitor for which replacements are not available.
 
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I've never submerged any chassis I've washed.

Just a simple pre spray with the kitchen sink faucet and then spray some simple green and let sit for a few mins. A light scrub with a paint brush then rise off and let dry in front of my ship fan. Done dozens this way without any issues.
 
I've never submerged any chassis I've washed.

Just a simple pre spray with the kitchen sink faucet and then spray some simple green and let sit for a few mins. A light scrub with a paint brush then rise off and let dry in front of my ship fan. Done dozens this way without any issues.
It also doesn't help that some people don't let them dry properly because they are impatient. I'm on the extreme side and let mine sit for a week and rotate them on a different angles to make sure they 100% drain. I'm no seasoned veteran, I've washed 17 so far.
 
I've washed a few boards now, including the chassis from this thread that turned out to be fine. I lay a box fan on top of a milk crate (so it can pull in plenty of air from below) and set the board on a couple small pieces of scrap wood to suspend it in the airflow. I turn/reorient it a few times over at least 24 hours. Seems to work fine so far.
 
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