G07: HOT blown after cap kit?

texasmame

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EDIT: FIXED - GO TO END.


Okay. Had a G07 chassis for my Spy Hunter that I suspected was okay but the tube's neck was broken. Did the tube swap and it was. Sweet. :)

Great, now that I know the chassis is fine, I'll recap it before I get into purity and convergence, etc. for the new tube.

Do a cap kit and install an NTE94 in place of the X04 and double checked the wiring and made sure it was correct and wasn't grounded to the chassis. Check.

Plug it back in and. . . dead. No crackle, no glow, no nothing.

I see F901 is blown and that leads to a shorted HOT on the flowchart. I didn't have access to a new HOT so I didn't replace it or even touch it during the cap kit.

My questions three:

~ Is there something you would do during the course of a cap kit that could cause the HOT to short? And, once it's shorted, is it crapped out for good and must be replaced?

~ Secondly, the PCB says 1.25A 125V for F901. Still trying to locate more of those locally but do have 1.5A 250V - would be a poor idea to try one of these, yes?

~ Lastly, could having used Arctic Silver for the heat sink compound for the new REG have messed things up? I've used it before for gaming purposes but not on a G07 REG. From what I've dug up here, it should have been fine, tho. FWIW, the REG case is not showing continuity with the frame, so thinking it's fine.

Bah.
 
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1) Yeah, something you did could have caused the HOT to blow, like a solder bridge somewhere. Make sure you discharge that filter cap before messing with the chassis further or you may get a BIG shock. You can go to Fry's and pick up an NTE 89 as a replacement for the HOT. It comes with a new insulator.

2) A 1.5amp 250v pigtail is fine. Some people just put wires in those holes and run them to a standard fuse holder they mount on the outside wall somewhere so they can just stick a normal fuse into it.

3) Some types of Arctic Silver has a high silver content that shorts out the part you are installing, so that could be the issue. You may want to check if the VR is blown, too...
 
1) Yeah, something you did could have caused the HOT to blow, like a solder bridge somewhere. Make sure you discharge that filter cap before messing with the chassis further or you may get a BIG shock. You can go to Fry's and pick up an NTE 89 as a replacement for the HOT. It comes with a new insulator.

2) A 1.5amp 250v pigtail is fine. Some people just put wires in those holes and run them to a standard fuse holder they mount on the outside wall somewhere so they can just stick a normal fuse into it.

3) Some types of Arctic Silver has a high silver content that shorts out the part you are installing, so that could be the issue. You may want to check if the VR is blown, too...

1. Thx. Yes, I did get my zap. Luckilly, I managed to still hold on to the chassis rather then drop it! They were out of HOTs at the local one (that's where I got the REG) - have to travel a bit further to get one tomorrow.

2. Gonna certainly do something with a fuse holder.

3. Guess I'll try to get some normal, generic zinc oxide or something with no silver content, clean it all and give that a shot. Also, how to test the X04 - same as the HOT as described in the flow chart?

Also, the flyback still looks fine and there was no smoke or metal confetti on powerup. :)
 
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Yeah, just test it like a transistor. the easiest spot is on the chassis where the three wires come in near X901.

And you should try it first with NO heat sink compound to see it working before you stick anything on it. I don't usually put any on (other than what was there originally), and I have no issues...
 
+1 to that. They really don't get very hot at all. I've even got one running right now with a piece of plastic in place until I get more mica insulators.

And you should try it first with NO heat sink compound to see it working before you stick anything on it. I don't usually put any on (other than what was there originally), and I have no issues...
 
I installed a HOT using arctic silver and it worked fine until I had to turn the H.FREQ up and it popped. When I removed it it's all blackened around the legs and some of the arctic silver oozed over onto the legs, so it may have been the reason it blew.

I installed a new one without it and it's fine, so I'd avoid the stuff in this case.
 
Well, new HOT, new REG, doublechecked for solder bridges, etc. AND installed fuse block for easy removal of fuse on chassis and. . .

Momentary crackle then F901 blows.

Guess the flyback is gone but it still looks the same as it did when it was working. :/

I have a few flies sitting around from TVs but not sure if they are good or not to throw in a chassis.

Only other thing I can ad is that some of the caps used for the kit were of higher voltages than recommended but my understanding is that's supposed to be okay.

Any other suggestions?
 
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Have someone else look at it?

Yeah, getting to that point I guess. I must be missing something and maybe another set of eyes would be good.

That, or trade this chassis and that complete dead K4900 monitor I have for a nice rebuilt, capped, working G07 chassis?

Anyone? Will post in the wanted section, too.
 
Okay, so now I'm pissed. I'm at the "look for the car keys behind the couch" level of panic/anger, so I just start searching G07 and reading.

I come upon this:

http://forums.arcade-museum.com/showthread.php?t=96894

The first cap I replaced was on the neckboard. I noticed that one leg was completely rotted off, as was the same value cap on the board. So, I install this cap and get to work on the board.

After the multiple checks for correct polarity on the chassis, never dawned on me that the neck cap might be the issue. Checked it - yup, I put it in backwards. FUUUUUU. . .

Corrected it and boom - all good.

DUUUUUHHHH!!!

:D

PS: I still have a G07 chassis and that 4900 available but the G07 is all original - no capping, etc. done yet.
 
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