New Chassis problems on a WG4900

srarcade80

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My WG4951 on my super pac was starting to go. I was getting the screen fading to black after being powered on for about 10 mins. Failing to get any better results from capping and fixing the old chassis, i dropped $56 and got a brand new wei-ya 820H chassis, installed it, got less than ideal results, no blue, and worst of all, it faded to black again after 10 mins. Is it safe to assume this tube is dead? Are the guns shot?

Also- its obvious to me now this chassis was not designed for an elongated vertical monitor, the maximum stretch the horizontal coil will go would probably fit a normal 19" but not a vertical. Can the width coil be changed out to something a little smaller to stretch it even more to make it fit?

Any recommendations for a TV tube that will work nicely with the 820H? Looks like that's the next move.
 
Does the neck still have glow after it fades to black ?
Does the monitor even have power after it fades to black ?

Also- its obvious to me now this chassis was not designed for an elongated vertical monitor, the maximum stretch the horizontal coil will go would probably fit a normal 19" but not a vertical.

A vertical monitor and a horizontal monitor are the same thing....just turned sideways.
Are there any other "width" adjustments on that chassis ? (pots, jumpers, etc)
 
Does the neck still have glow after it fades to black ?
Does the monitor even have power after it fades to black ?

Neck glow goes with the fade. Yes, power is still there.

A vertical monitor and a horizontal monitor are the same thing....just turned sideways.
Are there any other "width" adjustments on that chassis ? (pots, jumpers, etc)

Yes, width pot is turned to the max, it did buy me about 2" of space on the screen before it stopped.

This is the only 19" tube I own. It just looks... odd if its rotated horizontal, almost widescreen. If you compare to a 19" TV or PC monitor its about 1-1.5" more tube area. I guess its been so long since I have seen one in a horiz arcade game i have never noticed it.

send that wei-ya pos back to where you got it from and try again

I know.. I know.. some people really hate wei-ya. But I have to say, I've installed several wei-ya chassis and had excellent results before, especially on another RCA tube (but never tried one on a 4900 like this). I have a brand new 27" tri-sync that has one on board that is probably the best monitor i've seen, been going 2 years strong without a flaw.
 
All Wei-ya chassis have a width range jumper wire and two posts to set it to:

(N) narrower

(W) wider

I believe the factory ships it with the jumper set to (N) narrower.

With the power OFF, move the jumper wire from the (N) narrower post to the (W) wider post. Now turn on the power and see how much wider it is and adjust the width coil.

If you picture is still dark/dim, it's time to put the tube on a rejuvenator and test it. It probably is in need of rejuvenation.
 
The way the width coil works, the more resistance the coil provides, the narrower the screen gets. You can short over the two lugs of the width coil and it'll permanently make it as wide as possible. Sometimes even with it adjusted all the way out there's still a little bit of resistance through it....

Since your tube is dead though, you're going to be dealing with a different yoke probably whenever you swap it out so maybe you'll get more width out of the other one.
 
All Wei-ya chassis have a width range jumper wire and two posts to set it to:

(N) narrower

(W) wider

I believe the factory ships it with the jumper set to (N) narrower.

With the power OFF, move the jumper wire from the (N) narrower post to the (W) wider post. Now turn on the power and see how much wider it is and adjust the width coil.

If you picture is still dark/dim, it's time to put the tube on a rejuvenator and test it. It probably is in need of rejuvenation.

Thanks Ken, I will give this a try. I did another install of this same chassis/monitor at a friends house today, his had the same width issue I had, hopefully that will do the trick. Besides that, his color was looking really good compared to mine.

I am going to shelve my RCA tube I think until I finally get a proper rejuvenator kit. And the whole time I thought the old 4900 chassis was the problem! Too late now, the neck board snapped, and then I realized someone had glued it together. Oh well, I got a free 20" TV today, I will pull it apart and test the yoke tomorrow, hopefully it will work for now. If not I have a few other folks who were all willing to donate their old sets lol.
 
send that wei-ya pos back to where you got it from and try again

+1,000,000!!!

As far as I know there isnt anything on a 4900 chassis that you cant get and its easy enough to troubleshoot.

Matt
 
As far as I know there isnt anything on a 4900 chassis that you cant get and its easy enough to troubleshoot.

Except when you surprisingly remove the neck board to find out its been hot glued and solder bridged in 10 places and it crumbles in your hand as you pull it off the pins. I put out a WTB for one, still looking if anyone has.
 
Except when you surprisingly remove the neck board to find out its been hot glued and solder bridged in 10 places and it crumbles in your hand as you pull it off the pins. I put out a WTB for one, still looking if anyone has.

So long as the neck board is all still there its fixable. It takes some doing but after you've done a few of them it gets easier.

I might have a 4900 from a Pac that I scrapped. If I can find it you can have it.

Matt
 
So long as the neck board is all still there its fixable. It takes some doing but after you've done a few of them it gets easier.

I might have a 4900 from a Pac that I scrapped. If I can find it you can have it.

Matt

Wow that would be great! Thanks! Yea, the one i have now I tried putting it back together, it's a mess, solder bridges all over the place, one of the cracks went right down the middle of the 4 pin connector splitting it in half so it needs new pins plus the original hole for one is missing the solder pad.. traces damaged.. etc its a mess.

I ended up putting the wei-ya on a 19" RCA tube i got for free just for kicks and maybe a temporary fix. Everything looks perfect except the lower left hand corner where theres a huge black blotch. I fired up the tv before i tore it apart and it was good. I'm guessing it isn' quite compatible with the yoke? At least the H and V resistances were within tolerance.
 
I found the board PM me your address and I'll get it out today. The chassis isnt pretty but it doesnt look like anything missing or broken. I dont know if it works or not though.

Matt
 
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