, feeling dumb

[3AM]

One two three

[fernan1234]

Is this a consumer TV? At one point all the time, effort, and parts put into saving it will outweigh the cost of just finding another one on craigslist and such. Don't beat yourself over it.

[kamiboy]

The only permanent damage one can inflict upon a CRT is somehow breaking the tube, shortening, breaking the vacuum etc. Just about everything else is replaceable, though with varying degrees of ease, especially in regards to finding a replacement for sale.

Resistors, diodes and capacitors are readily available. Transistors are usually easy enough to source. An appropriate flyback is harder to find, and neck coils even more so. Of course if you broke several things at once it just makes diagnosis harder, and might require that you actually know what you are doing.

Pray you just shorted a transistor and that is it.

[3AM]

Is this a consumer TV? At one point all the time, effort, and parts put into saving it will outweigh the cost of just finding another one on craigslist and such. Don't beat yourself over it.

Yes, it's a consumer Sony Trinitron. I would mostly feel bad for the guy who brought it to me, and it definitely makes me less confident accepting jobs moving forward.

[Josh128]

Misery loves company so I'll share a similar experience I had. After going through the rigamarole of buying a brand new and otherwise beautiful Wei-Ya Makvision M3129 tri scan that had a beautiful picture marred by partially detached shadow mask that would warp and distort colors when warmed up and sending it back, I bought another one through a different vendor (Betson). Brand new as well, but unfortunately had a very ugly (to me) vertical geometry problem near the center right of the screen. After some troubleshooting with magnets and convergence strips I decided to remove the yoke and check some things. Unplugged the H and V deflection plugs and removed the yoke and found that some very small micro magnets taped to the inside of the yoke coil were obviously out of place, but I could see where they were once taped so excitedly I taped them back put everything back together and fired her up, feeling I may have accomplished something.

I got a single bright vertical line in the center of the screen and after a few seconds (probably 5 to 10) of trying to process what was going on, I unplugged the unit and to my horror discovered that I forgot to plug in the horizontal deflection plug back in. After correcting that and powering back on I was treated to a black screen and the dreaded "Wei-Ya 1 second click of death", proceeded by a burning electrical insulation smell. I quickly unplugged the unit.

I found the HOT was shorted, ordered a new one, installed it, and lo and behold, shorted again. Something is getting very hot on the mainboard, I think its power supply related, but havent determined that yet. The unit is still not operational. I paid $600 for it.

[leonk]

If you don't know what you're doing, you can do more than damage a TV -- you can hurt yourself and not know it.

Some of the circuits in the TV are there to prevent harmful X-Rays from being emitted!! I would look up the data sheet, it's always very clear which capacitors are part of the x-ray defeat circuit. Hopefully you didn't run the TV with those caps missing!!

[Josh128]

If you don't know what you're doing, you can do more than damage a TV -- you can hurt yourself and not know it.

Some of the circuits in the TV are there to prevent harmful X-Rays from being emitted!! I would look up the data sheet, it's always very clear which capacitors are part of the x-ray defeat circuit. Hopefully you didn't run the TV with those caps missing!!

All consumer units, especially larger ones, are made from thick, leaded glass designed specifically to block X-rays. Even in the event of X ray circuit failure, most potential X ray emission will not penetrate it. Also, whether the protection circuit is operational or not, normal operating voltages which produce normal pictures wont produce anything the leaded glass wont block. The circuits prevent excessive voltages in the event of failure of other components, which could generate stronger X ray radiation but would also give a telltale overly brightened picture from excessive cathode ray power.

He's got nothing to worry about from a medical perspective having run the set without vert deflection for a few seconds.

[3AM]

If you don't know what you're doing, you can do more than damage a TV -- you can hurt yourself and not know it.

Some of the circuits in the TV are there to prevent harmful X-Rays from being emitted!! I would look up the data sheet, it's always very clear which capacitors are part of the x-ray defeat circuit. Hopefully you didn't run the TV with those caps missing!!

All consumer units, especially larger ones, are made from thick, leaded glass designed specifically to block X-rays. Even in the event of X ray circuit failure, most potential X ray emission will not penetrate it. Also, whether the protection circuit is operational or not, normal operating voltages which produce normal pictures wont produce anything the leaded glass wont block. The circuits prevent excessive voltages in the event of failure of other components, which could generate stronger X ray radiation but would also give a telltale overly brightened picture from excessive cathode ray power.

He's got nothing to worry about from a medical perspective having run the set without vert deflection for a few seconds.

You sound pretty knowledgeable about these things. Thank you for sharing your story as well. It's good to know I'm not the only one who experienced instant regret like that.

What do you think my odds are that I only damage the transistors? I've tested almost every small component near them and nothing seems shorted or open. I only kept it on for a brief second, and the TV still powers on fine and gets voltage to the screen. The only thing I can think of is the HOT and vertical IC since the screen lost pretty much all deflection.

[3AM]

The only permanent damage one can inflict upon a CRT is somehow breaking the tube, shortening, breaking the vacuum etc. Just about everything else is replaceable, though with varying degrees of ease, especially in regards to finding a replacement for sale.

Resistors, diodes and capacitors are readily available. Transistors are usually easy enough to source. An appropriate flyback is harder to find, and neck coils even more so. Of course if you broke several things at once it just makes diagnosis harder, and might require that you actually know what you are doing.

Pray you just shorted a transistor and that is it.

Thank you for replying. I tested almost every small component, like diodes resistors and small disc caps, near the HOT and vertical IC and nothing appears damaged. I hope I just got lucky.

What are my odds that the damage was contained to such a small area? Since I know exactly what preceeded the damage I feel like there's a good chance at fixing it?

[Josh128]

If you don't know what you're doing, you can do more than damage a TV -- you can hurt yourself and not know it.

Some of the circuits in the TV are there to prevent harmful X-Rays from being emitted!! I would look up the data sheet, it's always very clear which capacitors are part of the x-ray defeat circuit. Hopefully you didn't run the TV with those caps missing!!

All consumer units, especially larger ones, are made from thick, leaded glass designed specifically to block X-rays. Even in the event of X ray circuit failure, most potential X ray emission will not penetrate it. Also, whether the protection circuit is operational or not, normal operating voltages which produce normal pictures wont produce anything the leaded glass wont block. The circuits prevent excessive voltages in the event of failure of other components, which could generate stronger X ray radiation but would also give a telltale overly brightened picture from excessive cathode ray power.

He's got nothing to worry about from a medical perspective having run the set without vert deflection for a few seconds.

You sound pretty knowledgeable about these things. Thank you for sharing your story as well. It's good to know I'm not the only one who experienced instant regret like that.

What do you think my odds are that I only damage the transistors? I've tested almost every small component near them and nothing seems shorted or open. I only kept it on for a brief second, and the TV still powers on fine and gets voltage to the screen. The only thing I can think of is the HOT and vertical IC since the screen lost pretty much all deflection.

Thank you but Im really very much just an infrequent dabbler at CRT repair and modification, Im not an expert by any means.

So you are still getting a beam lighting the screen when fed an image signal? If so, that is good, and more than my Wei-ya has, lol. FYI, if you lose both horizontal AND vertical deflection, you'll just get a super bright dot in the center of the screen when you feed it an image signal. This dot will damage the phosphor coat extremely quickly, so shut it off immediately if thats what you get. If you lose just horizontal deflection, you will get a vertical line when you feed it an image signal, and if you lose just vertical deflection, you'll get a horizontal line across the middle.

If you are not getting a beam, are you at least hearing the static from the tube being fed HV from the anode?

[3AM]

All consumer units, especially larger ones, are made from thick, leaded glass designed specifically to block X-rays. Even in the event of X ray circuit failure, most potential X ray emission will not penetrate it. Also, whether the protection circuit is operational or not, normal operating voltages which produce normal pictures wont produce anything the leaded glass wont block. The circuits prevent excessive voltages in the event of failure of other components, which could generate stronger X ray radiation but would also give a telltale overly brightened picture from excessive cathode ray power.

He's got nothing to worry about from a medical perspective having run the set without vert deflection for a few seconds.

You sound pretty knowledgeable about these things. Thank you for sharing your story as well. It's good to know I'm not the only one who experienced instant regret like that.

What do you think my odds are that I only damage the transistors? I've tested almost every small component near them and nothing seems shorted or open. I only kept it on for a brief second, and the TV still powers on fine and gets voltage to the screen. The only thing I can think of is the HOT and vertical IC since the screen lost pretty much all deflection.

Thank you but Im really very much just an infrequent dabbler at CRT repair and modification, Im not an expert by any means.

So you are still getting a beam lighting the screen when fed an image signal? If so, that is good, and more than my Wei-ya has, lol. FYI, if you lose both horizontal AND vertical deflection, you'll just get a super bright dot in the center of the screen when you feed it an image signal. This dot will damage the phosphor coat extremely quickly, so shut it off immediately if thats what you get. If you lose just horizontal deflection, you will get a vertical line when you feed it an image signal, and if you lose just vertical deflection, you'll get a horizontal line across the middle.

If you are not getting a beam, are you at least hearing the static from the tube being fed HV from the anode?

So I am definitely getting static and I can even hear the degausser working when I power it on. It's weird though, because the image isn't a solid horizontal or vertical line, and it also isn't a bright dot in the center, which I would expect if there was deflection failure. It was an off-centered (closer to the bottom left corner) oblong shaped splotch that was mostly blue in color.

I have never seen anything like it, which is part of the reason I'm so anxious about this set. The splotch returns in the same position if the TV is turned back on, or at least it did when I reinstalled the caps and tried it again. My guess is that maybe vertical deflection failed and triggered a protection mode, which froze the misdeflected beam off center and in a weird shape. No idea though.

[leonk]

All consumer units, especially larger ones, are made from thick, leaded glass designed specifically to block X-rays. Even in the event of X ray circuit failure, most potential X ray emission will not penetrate it.

OP wrote:

The splotch stayed there for a minute even after powering the TV off and unplugging it.

That's what made me think about X-Rays. Yes, the leaded front glass will prevent direct X-rays, and the metal shielding that modern TV's have in the back will prevent them from bounce back .. but he did this while the back was open, and shield off. Point is, don't mess around with TVs if you don't know what you're doing. A $100 TV (or even $5000 BVM) is worth far less than your life.

Hope I'm wrong.

[3AM]

All consumer units, especially larger ones, are made from thick, leaded glass designed specifically to block X-rays. Even in the event of X ray circuit failure, most potential X ray emission will not penetrate it.

OP wrote:

The splotch stayed there for a minute even after powering the TV off and unplugging it.

That's what made me think about X-Rays. Yes, the leaded front glass will prevent direct X-rays, and the metal shielding that modern TV's have in the back will prevent them from bounce back .. but he did this while the back was open, and shield off. Point is, don't mess around with TVs if you don't know what you're doing. A $100 TV (or even $5000 BVM) is worth far less than your life.

Hope I'm wrong.

The TV screen was facing me when it occurred, but the back was open. I like to think I know what I am doing and it was just a mistake that anyone could make regardless of their experience or education in CRT repairs. I have been repairing my own TVs for a few years and this is the first mistake of this kind that I've made. But you are correct. I am not an engineer or trained CRT technician, so you could say I don't know what I'm doing. Although I'm sure even they ocassionally forget to plug-in a connector or install something before powering on a device.

[Josh128]

Think about it like this: If the beam is not being actively deflected by current passing through the H and V coils, it WILL be a bright dot in the center. To be ANYTHING else, it has to be generating an electromagnetic field that is deflecting that beam away from the center, otherwise it will be in the center. There is likely some current flowing through one or both deflection coils.

Do you have a picture of the phenomenon?

[3AM]

Think about it like this: If the beam is not being actively deflected by current passing through the H and V coils, it WILL be a bright dot in the center. To be ANYTHING else, it has to be generating an electromagnetic field that is deflecting that beam away from the center, otherwise it will be in the center. There is likely some current flowing through one or both deflection coils.

Do you have a picture of the phenomenon?

I don't have any pictures. My first reaction was to unplug the TV and I haven't turned it back on since then because I don't want to cause burn in. It was maybe half way between the center and the bottom left corner, and it was just an amorphous shape, close to circular. It almost reminded me of a galaxy or a piece of the aurora borealis. An organic, somewhat circular oblong shape.

I will probably end up replacing the vertical IC and all of the electrolytic caps in the surrounding areas. If I turn it on and it still shows the same image, I'll be sure to take a photo and post it here.

[NoAffinity]

Probably seems like a silly question, but have you checked all fuses? I did a cap kit on an arcade crt, managed to get one cap in backwards despite rechecking things multiple times before powering on. Then spent 3 weeks troubleshooting the non functioning monitor even with cap back in the right way, only to find a fuse that was semi buried behind components and wires, and once replaced, it fired right up.

All that said, your story is also why I stopped working on other people's stuff. Too many risks, nobody's ever going to get rich doing other peoples' hobbies for them, and its a sure way to burn out on the hobby yourself.