A ton of monitors need help, Flow charts?

Brokenarcade

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Hey everyone. i have about 20 monitors that could use some attention. I usually send my chassis out to california to P and L but I was wondering if maybe I could work with some flow charts. I have about 13 k7500s in golden tees that I would like to get up and going and most of them are probibly caps that need to be replaced. i hate spending 50 bucks on a chassis that only needs a cap replaced. I was also wondering if you guys think putting a few pictures of each monitor up with the problem if you guys would know just by looking at them. I can soldier decently, have done complete chassis rebuilds before, but currently just looking to dump these games with working monitors, not looking to spend a boat load of time doing full cap kits. Any help is greatly, greatly appreciated.
 
Honestly, you'd be wasting your time to try to change out only one or two caps on a chassis like that. Most of the work is disconnecting and removing the chassis, then reinstalling it when you're done. Replacing one or two caps now is only going to cause you problems down the road, when other caps start going bad. You're really much better off doing a full cap kit.

If you have a bunch of monitors to do, then figure out what models they are, and put together one big order with Mouser or something and stock up on the necessary caps.

With K7000's, I see lots of bad flybacks. Might want to pick up some of those too. 7000's are a pain since there are so many variations, and when the flybacks go, they tend to blow up lots of other stuff too. Best thing you can do is catch flybacks before they fail completely. The ones with the white knobs are the failure-prone ones.

-Ian
 
If you're repair guys are only changing out a couple caps, then that's probably why you have to get them repaired so often.

I also charge $50 + parts, but I change out every cap during a cap kit. Costs a little more, but not that much...
 
With K7000's, I see lots of bad flybacks. Might want to pick up some of those too. 7000's are a pain since there are so many variations, and when the flybacks go, they tend to blow up lots of other stuff too. Best thing you can do is catch flybacks before they fail completely. The ones with the white knobs are the failure-prone ones.

-Ian

I'm fairly certain the K7500 flyback is different than the K7000 flyback, and I don't typically see flyback failures on these. Usually HOT and VR issues, cap problems, and heat issues on the neckboard transistors...
 
Full cap kits would be fine, but I assume that not all the of monitors that have problems are related to caps only. The games I have are not going to be put on route, just used in homes so the usage is low and I usually never have anyone with complaints. I have only had about 3 monitors go shit on me for a customer in the last few years. Is there a flow chart that could atleast get me to a point to where I know if it is a cap or if it is a transisitor or etc?
 
Randy Fromm has a flowchart for the K7400/K7500, but he doesn't like us posting them here....
 
We have an entire sticky thread dedicated to K7000 failures and repairs. Might be a good idea to start there.

As for what's a cap problem, and what's a transistor problem, here's some basic ones:

Capacitor problems: wavy image. jailbars. foldover.

Transistor problems: blows fuses. totally dead. makes chirping noise/no picture. missing a color. color stuck on.

Flyback problems: blows fuses. dead. makes arcing/zapping noises. flames. focus won't adjust.

tube problems: weak/missing color. stuck on color. dim picture.

-Ian
 
We have an entire sticky thread dedicated to K7000 failures and repairs. Might be a good idea to start there.
-Ian

Again - the K7500 is NOT one of the K7000 varieties. There are a lot of differences between them. And since it isolates the power on the chassis (no isolation transformer needed), it often has bad transistors, flybacks, etc without blowing the fuse.

Here is a K7000 chassis:

k700025.jpg


Here is a K7500 chassis:

k7500.jpg
 
Randy Fromm has a flowchart for the K7400/K7500, but he doesn't like us posting them here....

I got an email from him this past weekend asking me to take down a flowchart I had on my website. I complied without question.

Funny thing is, as far as I know, there were no external links to it from anywhere so how he found it is beyond me. :confused:
 
Again - the K7500 is NOT one of the K7000 varieties. There are a lot of differences between them. And since it isolates the power on the chassis (no isolation transformer needed), it often has bad transistors, flybacks, etc without blowing the fuse.

Ah. Yes. That is definitely correct. Sorry - been a long day, I don't know why I kept thinking the OP was talking about K7000's...

Yeah, a shorted HOT on a 7500 won't blow the fuse, it'll just put it into shutdown where it makes chirping noises.

-Ian
 
Well what do you guys think is the issue on the four i know off the top of my head.

One has an issue where you cant get it from scrolling vertically, it will hold for just a second and then continue to keep rolling.

Number 2 it looks very scrambled, not resolution problem, but almost looks like that.

Number three, starts up with a great picture then after it warms up, goes white and kind of shrinks or something. Any ideas on these?

I also think a 4th one is kinda shrunk on the bottom and stretched on the top.


I assume these are sort of common problems but hey If i knew I wouldnt need to be asking you all. I have about 6 of these golden tees in my shop and want to get them out relatively soon. thanks
 
The last two are most likely caps. The first two may have other issues but changing the caps won't hurt anything so you may aswell do them too.

Once you start troubleshooting these the first thing people are going to say is change the caps and then come back with your questions. It's $7 and an hour for a cap kit on those so you may aswell start by eliminating those variables. You probably have a few other issues aswell but maybe you will get lucky and the caps will be your problem there too.
 
Very true. Anyone recommend a good place that takes paypal? I will prob order a few kits asap. thanks
 
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