Sanyo 20EZ problem

rdudding

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I'm trying to get a buddy's Sanyo 20EZ up and running for him and have run into an issue I've never seen before on one of these monitors.

I've recapped the monitor, replaced the big filter cap and have confirmed that the B+ is at 108 v. Any ideas on what could be causing this goofiness??

FYI, a former owner of this monitor cut the chassis off of the tube and frame. They cut through the wire from the flyback to the anode, the neck board and the yoke. I have already spliced all those wires back together (solder, heat-shrink tubing and additional electrical tape over the heat-shrink tubing for added insulation on the high voltage wires.)

Thanks in advance guys,

--Rich
 

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I don't know what's causing your issue, but spicing together a cut flyback-to-anode wire isn't generally a good idea. That wire carries thousands of volts, and neither ordinary electrical tape nor ordinary heat-shrink tubing has the dielectric strength for that kind of voltage. The original wire is ordinary copper of course, but it's the insulation which is special; it is rated for at least 10,000 volts. This stuff, for example:

7EnJg0x.jpg


If I were to try that, I'd get some high-voltage, adhesive-lined heat-shrink tubing from 3M (very specialized stuff; you won't find it at the hardware store), and skip the electrical tape altogether so that the adhesive can bond directly to the existing high-voltage insulation on the original wire.
 
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I don't know what's causing your issue, but spicing together a cut flyback-to-anode wire isn't generally a good idea. That wire carries thousands of volts, and neither ordinary electrical tape nor ordinary heat-shrink tubing has the dielectric strength for that kind of voltage. The original wire is ordinary copper of course, but it's the insulation which is special; it is rated for at least 10,000 volts. This stuff, for example:

7EnJg0x.jpg


If I were to try that, I'd get some high-voltage, adhesive-lined heat-shrink tubing from 3M (very specialized stuff; you won't find it at the hardware store), and skip the electrical tape altogether so that the adhesive can bond directly to the existing high-voltage insulation on the original wire.

Thanks for the heads up on the high-voltage heat-shrink. I've worked on dozens of monitors over the years and have never seen anyone cut that wire before. I was hoping that I wouldn't have to replace the flyback because of the cut wire.

Mattspad, I'll check the caps again. I've never reversed a cap before, but there is always a first time. :)
 
Thanks for the heads up on the high-voltage heat-shrink. I've worked on dozens of monitors over the years and have never seen anyone cut that wire before. I was hoping that I wouldn't have to replace the flyback because of the cut wire.

I don't know if you'll be able to find that sort of thing or not. Adhesive-lined isn't necessary, but it's nice to have. 3M makes heat-shrink tubing intended for use on high-voltage bus bars, up to 35,000 volts, but I don't know if they make it in a small enough diameter for use on a flyback-to-anode wire.

It wouldn't hurt to replace the flyback transformer by the way, unless your monitor is particularly "low-mileage". Many, if not most, of the originals are already on their last legs. I've had three originals fail on me in my Super Punch-Out machine. I installed a pair of new reproduction ones in there several years ago and they've worked perfectly.
 
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Do you think the flyback could be causing that weird image?

I don't know. My three Sanyo flybacks all failed in the same way; they started arcing which caused a snapping sound and the picture to jump. It would do that once every 30 seconds or so. The picture wasn't affected aside from jumping each time the flyback arced.

I assume you have verified that the game board displays correctly on a different monitor?
 
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Yes sir. I'm using my tested and working Donkey Kong to test this monitor I'm fixing for my buddy.

The original monitor from my game works great...this one...not so much. :)
 
i personally wouldn't use the flyback with a splice in the anode. if you need a replacement flyback i stock them along with 18 other models.
 
Thanks for the advice guys. I will replace the flyback after I figure out what is causing the strange display. I don't want to spend the time and money for a new flyback until I can be sure that it isn't a bad tube or some other irreparable problem.

Any ideas from the monitor gurus??
 
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Thanks for the advice guys. I will replace the flyback after I figure out what is causing the strange display. I don't want to spend the time and money for a new flyback until I can be sure that it isn't a bad tube or some other irreparable problem.

If you decide to replace the flyback, keep in mind that the reproduction ones for Sanyos aren't a drop-in installation. I found Jeff F's picture album that he posted in my thread to be very helpful when I installed mine.
 
There is a lever like pot near the sub brightness pot center of chassis I can't remember what it's called is this I wrong position? Also did you reflow header where video signal cable comes it, I've had 2 have issues with that before, but picture was not stable.

It's always good to reflow sanyo chassis on the both the neck board and Main board.
 
That lever will make the monitor look like it's in vertical collapse if you put it in the test position, that's not the problem.

I've reflowed all the header pins on the main chassis board and the pots on the neck-board. I'm going to go back and re-check all my caps and reflow the rest of the solder pads.

Has anyone seen this warped display before and can steer me in the right direction?

Thanks in advance.

--Rich
 
I think you're on the right path, I'd replace that flyback to be safe though now that I think of it. Security0001 has nice flybacks at nice prices :3
 
I'm trying to diagnose this problem before I spend the time and money on replacing the flyback. If it is a bad tube or something that can't be figured out/corrected, there is no sense in doing something that doesn't cure this first problem.

Is this problem so unique that no one has ever seen it before?
 
I had a problem similar to this when I replaced my chassis on my Sanyo EZZ-C 14" this is what mine looked like. It kinda looks like yours is stretching too though?

e751e2e9d2d9c3e755dfb23d1bfbb145.jpg


This was the advice I was given and fixed mine. Not sure it relates to you so not saying this is your issue but I don't think there is any danger trying (famous last words!)



From the tech who helped me:

This is a problem I see with some 14" tubes using certain yoke configurations , it's a very simply fix that most manufactures realised and sorted out by adding a 1K resistor across the vertical coil on the yoke.

You need a 1K resistor ( Brown Black Red Gold ) 1/4 , 1/2 or 1 watt is fine , it can either be soldered on the yoke itself where the vertical wires connect from the 4 pin plug or you can solder under the chassis across the 2 pins.

When you measure the yoke the vertical coil is the one with the highest reading, on the 4 connector on the chassis it's the 2 pins closest together ( Not where the Red and Blue connect ).
 
Hmm...a yoke problem...damn, I've never worked on a yoke before. I know nothing about them other than tweaking a little convergence or flipping an image.

My monitor's image looks a lot like yours.
 
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