SHARP XM-1801 issues

[clanggedin]

I just finished a cap kit on both monitors in my Nintendo Red Tent cabinet. I also used siliconed the flyback on one which had a crack in it and it's still drying.

I plugged the other mintor into tha cab and powered it up and it works fine except the is a buzzing noise coming from it. It is not coming from the speakers either. It's coming from the back of the monitor. It is not the same sound the other one has when the flyback was cracked. It's just a buzzing sound, but it's very noticeable.

What have I done? Is there something I didn't plug in all the way? Have I cracked something??

The game and screen look great, it's just the annoying buzzing noise that I need to figure out.

Should I pull the monitor back out and check all of my solder points? Or is it something else?

[Ken Layton]

Probably the metal cage around the flyback or that clear plastic flap attached to the cage. Double check placement of the wiring harness. Also be sure you did a nice neat job of soldering and that all assemblies/covers removed during the capkit have been properly secured.

One other thing: Is the suction cup (anode connector on the picture tube) securely connected underneath the suction cup?

[clanggedin]

I removed the flyback cage completely on the monitor as well as the plastic flap attached to it. You had said something about the cage keeping too much heat in, so I removed it entirely.

Should I put the cage back on??

[Ken Layton]

No, leave that cage off. It will help to extend the life of that unavailable flyback. Be sure you wrote the model information that was on the side of that cage down somewhere on the monitor for some future repair tech's information.

[clanggedin]

OK.. I pulled the monitor back out and checked all of the solder points and everything looks fine. I also doubled checked that the neckboard was connected securely. When I plugged it back in this time I noticed that there is one of those lines you get on your TV sometimes if someone plugs in a vacuum cleaner or blender when you are watching TV. It's faint but it changes the black around it to a slight red as it moves down the screen.

I used a cardboard tube to see where the noise is coming from and it appears to be coming from the neckboard itself. Would a cracked board cause this??

[Ken Layton]

Could be bad solder on the neckboard.

[clanggedin]

I powered up the other monitor I had today that I repair the flyback on and it makes the same sound. I wonder if all SHARP monitors make this sound and I'll just have to live with it.

I'll keep plugging away at figuring this one out. All I can think of is there was one cap that looked like it was touching another cap or resistor before I replaced and and when I replaced the cap I made sure the solder didn't touch the other resistor or cap. It was like C420.

Could that be causing the buzzing sound??

[Ken Layton]

I don't recall the two I fixed making any noise, but I remember leaving the clear plastic in it that was attached to the flyback cage. The cage was removed completely, but I made sure all wiring was layed out exactly as it originally was.

[clanggedin]

I'll put the clear plastic back on one of the montiors and see if that helps. I will also reflow the solder so the points are touching on one of them and see if that makes any difference.

[clanggedin]

I have finally pin-pointed (for sure) where the sound is coming from. It is coming from the Isolation Transformer. I moved over to one of the air vents on the bottom of the cab and sure enough the sound is coming from that.

I went to Bob Roberts site and read how to fix the "Alarm Clock" buzz, but the transformer in this cocktail is a metal box and not the block like others I have seen. I'm going to take the cover off of it tonight to see if I can see what is making the noise.

[clanggedin]

Well, reoving the cover on the isolation transformer fixed my problem. No more buzzing. Now to fix the audio on the Vs. Golf (Ladies) section.