Monitor chirps = bad flyback?

AtariShag

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Just doing a quick check here - if I have a monitor that makes a chirping or ticking noise does that automatically mean that the flyback is bad on it or could it be something else? THe monitor doesn't show an image but there is that chirping noise.

Also, I am a noobie at testing components and I know that you are always supposed to check the HOT but how do you check that with a multimeter to know if it's good or bad? Just do a continuity check on certain pins?

Many thanks in advance
 
usually itas shutting down.. usually due to a freied hot..

to test for a shorted hot, oum betwene the center leg and the right leg, if it reads 100 ohms or less, pull it and restest.. if it still reads real low, its bad...

the closer to 0 ohms the greater chance its shorted out...

would prefer for resistance between those terminals to be 1000 ohms or greater ..
 
what kind of monitor are we talking anyways?

my 25" neotec made the best beep chirp.. sounded like a hollywood movie bomb chirping its way to 0.. kaboom lol
 
Thanks for the tips! What would cause a HOT to fry? I did see a capacitor that had blown a small hole in the top but I'm not sure if that's the cause of the problem or just something else.

As for the monitor, it's a Pentranic, it came out of a Mars Matrix cabinet.
 
Thanks for the tips! What would cause a HOT to fry? I did see a capacitor that had blown a small hole in the top but I'm not sure if that's the cause of the problem or just something else.

As for the monitor, it's a Pentranic, it came out of a Mars Matrix cabinet.

yeah, if you have blown caps then it could contribute to it not firing up, probably cause you have energy that has nowhere to go. I've seen it in computer motherboards and video cards with blown caps, they just won't work at all. I got a monitor now that supposedly won't work cause of caps, but the ones in question are polyester, not the cylinder kind, and I haven't had time to strip the chassis out to ATTEMPT to make out the numbers on the caps.

you know what the guys are gonna say: install a cap kit first.

I know nothing about Pentranics. I figure with how anal everyone here is (WG or bust) and how much I see about Pentranic and Kortek monitors that there's a time and a place for everything. any word on their quality?
 
In modern monitors with switch mode power supplies.....that "chirpping" is the over voltage protection shut-down. A bad HOT can definately cause this....as can a bad flyback(these are the more common causes), but so can a lot of other stuff. Basically, there's a short somewhere.

Edward
 
Thanks for the tips everyone. I have a replacement HOT I can put in there but if it's a short somewhere, I guess I am going to have to do some work beyond that.

As for the quality of the monitor, it wasn't great when I first got it. The color was already washed out and I figured it would require a cap kit eventually but I decided to hold off when it was obvious that pulling the chassis out would be a nightmare (and it was).
 
I know nothing about monitor repair, when you say you have a extra HOT you can install, what exactly is a HOT, are you referring to a flyback? I know on the chassis board one of the solder points is labeled HOT. Anyone have a picture showing what the components are all called?
 
OK, google is now my friend. So HOT is a Horizontal Output Transistor. Next question, why is it recommened to replace this when replacing a Flyback? How are the two linked as far as doing repairs?
 
Most of the time that a flyback goes bad, the HOT goes bad with it - I'd guess 90% of the time. And I'd say a flyback is bad maybe 50% of the time a HOT is bad, but that percentage can go way up depending on the chassis.

It's easy to test a HOT to see if it needs replacement, but you need a ring tester (love mine!) to test the flyback. If your HOT is bad and your flyback LOOKS okay, you can try replacing the HOT (for about $4-8) to see if it blows again. If so, then you probably need to replace the flyback, but that's not always the cause of a HOT blowing. For example, on a K7000 you can blow the HOT even with a good flyback if you power it up for long without connecting the DAG wire to the neckboard...
 
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