G07 no hv

Zinfer

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I recently came across a Bank Panic sega convertacab and picked it up pretty cheap. The problem was no power. I put it in storage for a while, but now have some time to put into it.
I pulled the monitor, the monitor was shorting a 3amp fuse which was killing everything.
First thing I ran a complete cap kit. replaced the HOT and 2SC1106 voltage regulator. I replaced the power cable with new and a disconnect. I replaced the small pigtail fuse. (It looked funky - had some kind of condensation inside it)
The game is up and running, but playing blind. No HV, no static charge on the monitor, no neck glow. Metered the main power input wire at the chassis contacts. It's got 120 going in. I ran through the flowchart and pulled the x701 transistor, still nothing. I then ran through and reflowed alot of contacts. Still nothing. I checked the large ceramic resistor on the side, 161vdc on crt side(white wire), 168vdc on the other. I'm not seeing any cracked or cold solder joints.
I'm just guessing at this stage, could the flyback be bad? Shouldn't a bad flyback smoke or spark that was bad? I haven't run across many bad ones but I would think they would give some clear indication. Just not sure where to go next on this G07.
 
often not

I'm not saying that it is the flyback but flybacks go bad all the time without any signs. If your lucky they will show some arc but not always. I'd say change it, they are cheap enough and will probably need it sooner or latter. I'd have to research and read my notes to see what I think it is its been a few weeks since I have worked on one and its crazy how much you forget so fast. When I get time I will look through my notes if someone doesn't answer first. If you give up there are several of us here including me that will sell you a working chaise. I have both rebuilt and repaired chaises.
 
I would change out the flyback just to eliminate that from being the problem,come across several G0-7 flybacks that died quietly.
 
The monitor is in high voltage shut down. Check the solider joint on transformer t501 and stuff in that area. That happened on one of mine. If you listen real close you should be able to hear the monitor crackle up then go down.
 
I would change out the flyback just to eliminate that from being the problem,come across several G0-7 flybacks that died quietly.

Although the fly should have been changed out during the cap kit, it is not the problem here as the monitor is in HV shutdown.

Check your work on the 2SC1106 and make sure it is right.
 
The last two times I saw approximately the same voltage on both sides of the resistor - as you do - and the resistor was good, it turned out to be these issues:

1) The wires were put onto the VR backwards.

2) The C1106 was accidentally replaced with the 2SD870 used for the HOT....
 
The C1106 was replaced by a brand new 2SC1106. I'm pretty sure I accurately placed it, but obviously somethings wacked. No video at all. Monitor dead. Game playing blind.
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I will try and pull the chassis again and check out those two this weekend.
 
Ok, well I pulled the fly and changed it out with new. I pulled T501 and T503 and replaced them seperately from a donor G07. None of this had any influence.
I'll be hanged if I can find the problem. It's right in front of me but I'm not finding it.
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I've listened very intently for that and it never occurs. As if the monitor isn't plugged in..
But I've tested the input and have 120v and have taken measurements on the ceramic resistor.
I've even tried it in darkness and there is no glow at all on neck or video side.
I've known monitors to smoke, spark, blow fuses but never just sit there and do nothing at all. Just odd.
I've taken to just removing the anode suction cup by hand without discharging, because the tube's not getting any charge whatsoever.
The monitor is in high voltage shut down. Check the solider joint on transformer t501 and stuff in that area. That happened on one of mine. If you listen real close you should be able to hear the monitor crackle up then go down.
 
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R908? X901/x902?

Checked Resistor R908. Ohms out at 10.80
X901 & X902 getting around .500 and .600 on diode setting if I'm hitting the correct legs right.

D508 and D301 get readings on both sides of the diodes so something's wrong with that. But I don't know if they are 1N914's, 1N4148's or what? Electrohome doesn't exactly help much with their diode descriptions in their docs. They do designate which is a zener but those are not in the list.
What exactly is a 1SZ473H?
 
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You need to fix neck glow first. Meter the white and black wires for continuity from the chassis just left of flyback to the neckboard (follow the wires up to the neck board) check for cracks in traces around flyback next

Andrew
 
Balls!
The black and white wires from chassis to neck board continuity test out fine. Followed traces from flyback, continuity tones out good. 6 and 7 stop at C524 cap.
 
Well I went over about everything reflowing. Just not seeing anything bad at all. I'm going to try one last time putting it back in the cabinet and firing it up tomorrow.
 
Still looks like you haven't fixed the HOT or REG. The HOT appears to be grounded to the chassis from your pic, and the REG ain't much better.
 
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