WG U2000 burnt resistor

LittleTimmy

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I have a 25" Wells Gardner U2000 chassis out of a T2 game. The monitor is dead, no noise, so I did the cap kit, new flyback, horizon. update and voltage reg. update. Nothing. I was adjusting B+, so when I got it to 127 volts, resistor 760 got red hot and I think it's toasted. I already replaced it because it measured like 220 ohm and it's suppose to be 470.I put the correct wattage resistor in it, anything else I can check? I also checked R765 and it was good. What else should I check?
 
Your adjusting the voltage to high should be
around 120v's
Lift W156 a bare jumper wire coming out of
the power supply. Hook a 60 to 75 watt bulb
to jumper and the other side to cold ground
and adjust the B+,confirm your power supply
is adjusting within range,if the 127v's won't go lower
then your problem is in the power supply..
And because your B+ voltage is to high thats why r760
is burning up.

Or if the power supply is working good then
i have found R760 open and Q708 shorted and Z702 a 12 volt zener
below 12 volt's, it should be around 12'vs if good.
and check z705..for short. Replace all at once,clear any shorts
then test again,Good Luck!
 
Hey, thanks for the reply. The power supply should be fine because my voltage was 110, then I adjusted it up from there. I order new zener diodes and a set of transistors. I'll let ya know what smokes next! Thanks again for the help.
 
Ok, no change. According to the WG website, I should have 127.00 volts at TP 202. The voltage started around 110v, then I adjusted up to 120v for now, no smoke yet. I checked other TP's ...TP 203, TP204, and TP205 is around 0. Now what else can I check?
 
Ok, no change. According to the WG website, I should have 127.00 volts at TP 202. The voltage started around 110v, then I adjusted up to 120v for now, no smoke yet. I checked other TP's ...TP 203, TP204, and TP205 is around 0. Now what else can I check?

You need Horiz-Drive,check pin10 of Ic u701 for 12v's
it should be there.If so Need to check pin 12 for horiz-drive
if no output then the ic is bad.
Any collector Voltage On Q703 Horiz Driver.
The Voltage comes from those parts you replaced to pin 10
of Ic U701, all the ic need is 12v to start for H/V Drive
To the base of Q703.
Tp201 X-Ray Protect
Tp204,Tp205, TP203 are scan derived voltages coming from the flyback only.
 
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Ok Ohm, will probably just replace that IC, the game is at my friends house and I don't have the room to bring it here and I already have the chassis back home with me already.I will let you know after that. Thanks for some direction.
 
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This POS is really pissing me off!! Ok, Changed out the U701 chip, still nothng. I turned the B+ to 127v per the WG site, still nothing. My voltage at TP 203 have like 1.2 volts. The voltage at pin 10 on U701 is like 8.5 volts. What else now??? I have a few quarter sticks!!!
 
This POS is really pissing me off!! Ok, Changed out the U701 chip, still nothng. I turned the B+ to 127v per the WG site, still nothing. My voltage at TP 203 have like 1.2 volts. The voltage at pin 10 on U701 is like 8.5 volts. What else now??? I have a few quarter sticks!!!

The Z702 Needs to be atleast 12v's
You need the Horizontal output circuit working to get any voltage from TP203
You already replaced the fly,caps,the zener,Q708,R760,U701
Did you get C712 in correctly? 1000uf 16v's
Any voltages on Q703 or Q704?
are the HV caps good next to the fly?

I would have pulled the whole crt and chassis in 20 minutes
and brought it to the shop fixed it then test it,first.
Not every monitor just needs a cap kit..

Using the schematic?, any open traces,did you solder the Horiz driver Transformer?
Its not always the same parts each time,you have to find the bad ones.
It's ok to have 120 or 127 when you checking the HOT circuit,you will still have a raster
if the Horiz Output circuit is working.
Is your yoke connected?
Good Luck!
 
you have a meter....check R301 ....it is a 1.2 ohm resistor that is in the 15 volt section that gets turned into the 12 volts that ohmerone is talking about. It get hot somethimes and starts to go up in value. This is a 2 watt resistor ....if it gets over 1.5 ohms you need to replace it.
 
Hey,
I finally have neck glow! It was a open transistor and a open resistor. Here's my next problem.... I have a solid green line down the middle of the screen. I don't know if I still have a monitor board issue or a game board issue... Any thoughts??
 
vertical line or horizontal line?

If horizontal check for shorts on the U601 first (only one leg should have continuity to ground. Also check for an open R303 and shorted D302. They are just to the right of the flyback. And of course check that the vertical yoke is hooked up correctly and that the vertical size pot isn't broken...
 
Thanks for the fast reply Modessitt, will check tomorrow. It was a horizonal green line.I had a few beers and shots to celebrate neck glow on this. This thing has been really kickin' my butt!!
 
Ok., Checked it out. U601 was new, I put that kit in it. I checked to see if it was shorted to ground, all measured good. Also, both the resistor and diode measured ok as well. I am pretty sure I had everything hooked up correctly.Vertical size pot looks ok, should I measure it with my meter? Anything else I can check?

richiewoo, I had a open Q703 and the resistor was R719.
 
Good question... I guess I should have measured that. I will reinstall and post back with the answer.
 
Ok, finally got over there, reinstalled and took some readings.... I adjusted the B+ voltage to almost 127 on TP 202. The voltage I have on TP 203 is too high, it's 175, it should be around 126 volts. Also, TP 205 I have 0 voltage. The flyback is new..Should I put the old one back in? I also noticed now that when it is on for a few minutes, the green line goes away, and all I have is a black screen.
 
When I have vertical problems with these monitors, I will replace all the electrolytics in the 600 section. I will also check/replace D302, R303, C305, D603, and U601. If any of these are bad and not replaced you have a risk of taking out your new vertical IC.
 
Thanks Sarge77, U601, R303, andD302 are new and I rechecked them and they are ok.I'll take a peek at those around the 600's.
 
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