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My journey learning to work on K7000 chasis

learningStuff

learningStuff

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I’m currently working on a k7000. (My first attempt at a chasis repair) It was getting vertical fold at the top. I replaced the flyback because it was the white knob versión and was literally falling apart. I then accidentally turned on the cab without connecting the anode cap which blew the fuse, HOT, and voltage regulator ‍♂️. A very fun lesson to learn. So now I’m awaiting replacement parts, and trying to figure out what could be causing the folding. I think IC2 May need pulled and checked but I’m not sure how to properly test the IC with a multimeter. WIll update as I go!
 
Very interested in this. I successfully repaired a k7000a as my first monitor. Very nerve wracking at first. The story of the cabinet repair is in these very forums.

Are you doing a cap replacement? While you have it out and are working on it may be worth your time to change those out as preventative maintenance should they be the originals still. Also be sure to check your B+ after changing out the Caps or VR.
 
Yes I have a cap kit so I'll be replacing them while it's out. I'll also check the B+ voltage. I have a K7000A that the image doesn't get wide enough so that will be the next one to work on. I'll check out your journey with it! After those 2 the next is an Electrohome G07 with vertical collapse and a Hanatrex MTC9110 that won't keep vertical sync. So much to do!
 
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K7000’s are very serviceable chassis’. I like them better than G07’s, tbh. There’s lot of info out there on them, and replacement parts are readily available.
good luck on your repair. Hopefully you didn’t take out too many components when your HOT blew.
 
Please read #9
 

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It's most likely r80 and r78 need to be replaced. That's a common failure for vertical fold.
 
K7000's are fun as heck to fix, easy to work on, and and and and and, inexpensive. There is one key to learn that makes everything else easy and that is to learn how to measure the B+. Here is a link to video marked at the right spot that demonstrates it:


You'll need a digital multimeter of course. Then once you have this figured out, just follow good ole' Randy Fromm's flow chart below. Can't be easier.

montior-flow-chart-wells-gardner-k7000-large-chart.jpg
 
learningStuff said:
I’m currently working on a k7000. (My first attempt at a chasis repair) It was getting vertical fold at the top. I replaced the flyback because it was the white knob versión and was literally falling apart. I then accidentally turned on the cab without connecting the anode cap which blew the fuse, HOT, and voltage regulator ‍♂️. A very fun lesson to learn. So now I’m awaiting replacement parts, and trying to figure out what could be causing the folding. I think IC2 May need pulled and checked but I’m not sure how to properly test the IC with a multimeter. WIll update as I go!
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Ignore what others say about white nob flybacks, it's bad information. Replace the flyback if it has failed, or you suspect it might fail soon, but not because it has white nobs.

It's also worth noting that almost all aftermarket (non-OEM) flybacks are lower quality than the originals.

There are lots of people replacing parts left and right, that do not need to be replaced. Remember that most of these parts are not being manufactured anymore, and the remaining supply is limited.

When you start replacing good working parts, you introduce variables that can cause more problems.

So my advice is: try to troubleshoot and fix problems, instead of throwing parts at it.

Your symptom is vertical foldover, so best to start in the vertical circuit.

Hope you get it working again, but if not, don't be afraid to send it out for repair.
 
Thanks for the info! It was super cracked unfortunately so it had to go. The previous owner kept it attached with twist ties. Sadly I’ve been very busy and haven’t had the time to go back to this yet. Hopefully soon
 
necro bump but hey this flowchart saved my butt so I wanted to say thanks for posting @RealMFnG

I did my first flyback replacement recently and it did not go according to plan and as I was googling for help this forum page showed up and I had that flowchart open on my bench as I troubleshot my work and it was immensely helpful once I learned measuring B+ and went thru the steps.
 
LittleLarrySellers said:
necro bump but hey this flowchart saved my butt so I wanted to say thanks for posting @RealMFnG

I did my first flyback replacement recently and it did not go according to plan and as I was googling for help this forum page showed up and I had that flowchart open on my bench as I troubleshot my work and it was immensely helpful once I learned measuring B+ and went thru the steps.
Click to expand...
Another satisfied customer, woot! So what was the issue?
 
Original flyback with the white knobs had a large crack in it so had to replace that and then the flowchart/testing B+ helped me find problematic resistors that had cracked solder joints. After all that I ended up with a chassis that would work but with intermittent shutdown which lead me to learning about and fixing the out of spec shutdown pot back to 9.8V. Did 2 hours of burn-in on my bench and no issues since then and a nice picture!!

I had a scare with the blue gun as well but seems to have resolved after using the rejuve and clearing shorts.
 
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