WG U5000 from h*ll

[Davester]

Hi Folks... I'm another long time lurker with a U5000 problem.

Had the monitor die on me a couple of weeks back... did the cap kit thing and replaced the HOT while I was at it.  (This didn't help).
Through troubleshooting, I found that R765 (3.3K) had gone open.  No burn marks, no nothing.
Replaced the resistor and the monitor fires up.  It's not long before I notice the magic smoke escaping from this resistor again. 
Replaced the resistor (again) and still the resistor burns. 
Now, from my research, I know that this resistor is in parallel with a Zener diode.  I check the diode out of circuit and it appears to be OK.  I even compared it with another zener from another questionable chassis and it looked OK.
Any suggestions???  Any help would be muchly appreciated.

Thanks.

Davester.

P.S.  For anyone that's still with me, here's my other sob story with this U5000....
I installed the cap kit, HOT and resistor and mounted it back in the game.  I thought I would be smart and monitor the B+ when I fired up the monitor.  So to get at the B+ test point, I had to remove the Horizontal Width coil connector and attach and alligator clip to it and to my multimeter hanging off the front of the game.
I fired up the monitor and only saw a bright vertical line.  WTF???  Before I could pull the plug the screen went blank.  I took a walk to cool off a bit.  Only then did I realize that I forgot to plug the Horizontal Width Coil connector back in.
DOH!
And that's what I call a life lesson.

[Ken Layton]

This chassis is plagued with problems. That's why it was replaced with the k7500 series.

There are 3 "service kits" you need to buy from the parts department at Wells-Gardner:

Power supply kit

Vertical Sweep kit

Horizontal output kit

You can Google for the part numbers.

[Kevin Mullins]

Through troubleshooting, I found that R765 (3.3K) had gone open.  No burn marks, no nothing.
Replaced the resistor and the monitor fires up.  It's not long before I notice the magic smoke escaping from this resistor again. 
Replaced the resistor (again) and still the resistor burns. 

Oh yes.... that's a lovely occurence I had the not so luxury of chasing down once.
There's several components you'll want to check and replace. I'd have to look at mine again to remember which all. They are mostly grouped right around that R765, but there was also a transistor (Q703 if I remember correctly) that you'll want to check that's farther away fromt hat area. And I think it also had one of those smaller transistors (I forget the number on that one) near that resistor that might "check good".....replace it anyways. Along with the zener you already mentioned

I'll try and take a peek at mine again.
I didn't take very good notes on that one....too busy pulling my hair out. 

Now the horizontal width coil episode you had is a whole different story.

[Davester]

Hi Folks... thanks for the responses!

Ken - I forgot to mention that this monitor already has all of the upgrades installed when I got it.  (Obviously didn't help too much.)

Kevin - thanks for the follow-up.  (I thought I was going bald because of my wife & kids... it's really this monitor that's doing it to me.)  If you could give me any more hints when you look at your monitor, I'd appreciate it.
I'll have to order in the zener diode that is in parallel with that resistor.  (I figure the diode goes open under load, all of the current must be smoking the resistor.)   Unfortunately the local electronics shop doesn't stock them.  (And I don't think Digikey would appreciate a 49¢ order.)

Again, thanks for your help... I'll let you know how I make out.

Dave.

[ttontis]

So I guess the next question would be is it worth it to upgrade the monitor to a K7500 and save the trouble of repairing the old U5000?

Ted

[Davester]

I was thinking of replacing the chassis by going down and visiting Nieman Monitors... <insert plug here>
But for now, it's personal... I will not let this U5000 beat me!  (At least until my next paycheck!)

Dave.