25k7191 No Power?

ArcadEd

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This is in a blitz 99 cab that used to be a Killer Instinct cab.

Anyway, I get a very faint monitor sound when I turn it on, but not that big sound you know you hear when you turn one on. I don't see any glow on the tube either.

What is a good starting point? I tested voltage out of the ISO, it's fine. I tested the Voltage Regulator on DC and It's 129 on the blue wire and 143 on the red wire.

Should I start with the fly back? The fuse on the board is good too.

Thanks.
 
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Check the chassis for cold joints, especially around any large resistors. If your B+ is stable at 129 you should have a picture. Have you tried turning up the flyback?

Personally, I would pull the chassis then replace the flyback, caps, VR, and HOT. While it is out I would go over the solder joints and ensure there are no lifted traces or cracked joints.
 
Thanks bud,
The board was nasty dirty so I did a washing and I'm waiting for it to dry. I'll take a look at all that stuff. I have a K7000 cap kit on hand, but not a fly back.

I will try increasing it, but is has the stupid glue on the knob.

I know this sounds weird, but you know when you turn on a tube you feel that static on the front of the screen if you touch it. I don't get that.
 
if you don't get that static you are probably in HV shutdown.

do as suggested and cap it and re-flow the major problem areas.

start fresh then see what happens.

if you still don't have a pic after all the maintenance. pull one side of D10 and see if it fires up. if it does you may have a bad VR.

Peace
Buffett
 
OK, I found a pretty bad solder on one of the flyback pins. I did an ohm test to another point on that path from the pin and go nothing. Soldered it back up and got a connection.

Gonna wait overnight for the water to dry out of this thing and see what I have. Thanks again.
 
OK, that one bad solder point on the flyback pin seems to have fixed it.

Picture looks good, only problem is the horizontal position has to be maxed out to get the picture centered.
 
Why yes, yes I did. Here is a picture of the bad solder.

Is that what you meant?
 

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check the horizontal position jumper and adjust it then your pot should have more adjustment.

look over near to the width coil and you will see the jumper and two extra posts.

Peace
Buffett
 
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