Dig Dug Cocktail G07-FBO 13" Needs Help

I confirmed 129VAC coming across the black wires.
Click to expand...

That seems high, but is most likely OK.

Voltage across F902 is 0.000 which confirms the fuse is good.
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Fuses shoud be verified with a continuity test. Do it with the power off and you should have almost no resistance across the fuse to verify it is good.


Double checked and there is no DC voltage at either leg of R901.
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This needs to be investigated. Is there voltage at F902? What about F901? Place the black lead on any chassis ground and probe with the red lead.
 
Yeh, I'm not liking the readings I'm getting and I don't like these board mounted fuses. I don't like testing them in circuit either.

I think this begs the question, where can one get fuse holders that mount into the 4 "rectangular" slots in the chassis??
See below

-- --

-- --

Evan
 
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I've got fuse holders that are perfect for a G07 chassis (and whenever I find a G07 with a blown fuse I replace the pigtail with one of these). They hold the mini fuses. You'll have to modify the chassis slightly to accomodate the legs (they're slightly wider than the holes in the chassis, where the pigtails go through). I use a drill bit, then use a fibreglass pencil to remove the coating from around the holes for a solder point.

But...I don't think that's your issue, anyway. I don't think. What's your B+ now?
 
My B+ is definitely 0 now :) I have no fuses in there haha.

Likely a very stupid question, but in the interm, can I solder a wire strand to the end of a regular fuse to serve a through-hole tap until I can find some board mount holders?
 
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wxforecaster said:
My B+ is definitely 0 now :) I have no fuses in there haha.

Likely a very stupid question, but in the interm, can I solder a wire strand to the end of a regular fuse to serve a through-hole tap until I can find some board mount holders?
Click to expand...

yes, you can it is a rather common hack
 
Peale, 902 is good. 901 (giving me shady readings) broke in half when I removed it However, given the discoloration of the inside glass and my inability to locate the filament, I think it's a fair bet that it was not good.

Will report back shortly after I solder in these new ones. Of course a betting man would wager that 901 will blow again
 
Sigh. Well, one cool thing learned. Extra cap legs make awesome fuse mounts.

Immediately upon firing it up F901 blew with a nice flash, confirming my suspicion.

So, eliminating a page of stupid posts by me, here's where we stand with a brief summary

Two days ago: B+ of 166V. Monitor in HV shut down. Remove X701 collector leg, get a picture, B+ measured at 144V at X01.
Yesterday: Did a cap kit and replaced the HOT. Power it on, F901 blows (it was such a nice solder job too!)

Although the flyback inspects good (no cracks/leakage), I'm thinking not so much. The only other thing it could be (correct me if I'm wrong) is the HOT, which I replaced yesterday and confirmed it's insulated properly and not grounded to the chassis. Unfortunately Bob said he's out of flybacks til January, which is why I didn't order it to begin with. Anyone else carry them?

If the F901 blowing is because the HOT replacement caused the flyback to finally crap out, then I'm not sure repairing that section addresses the original problem (high B+) -- which sounds more and more to me like it is the regulator, but as I started earlier I'm not sure how to test it since my 19" monitor regulators only have two pins and the 13" one STR383 has 3.

Evan
 
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I carry them.

If you want to test your HOT, take your meter, set it to Ohms, black lead to frame, red lead to the case of the HOT. Open or high resistance generally means it's good, shorted when not.

The same test can be used for the VR.
 
Peale,

By case I assume you mean the outside "bottle cap". Resistance comes out to around 8.5K Ohms on both the VR and the HOT. Diode mode was open. Continuity mode no buzz and read open.

I did the same test on my working 19" G07 and got the same thing.

The flow chart says that for 901 to blow, only the Flyback and HOT could be bad. It also suggests that if the flyback is bad, the HOT is bad. Yet, I don't see the cracks/leak in the flyback, nor does the new HOT appear to be blown.

Evan
 
I'm going to assume they're fine. For now.

Replace the flyback.

It's a G07. This is one of the things that should ALWAYS be replaced, if it's original.
 
Oh I agree completely, but Bob was without. I probably shouldn't have replaced the HOT by itself, but alas I made a mountain out of a mole hill.

Been shopping around on the net, but please PM me with a price. Based on the "expert dialogue" back on page 2 I assume a 19" CBO will work in the 13" FBO?

Evan
 
While I await on the flybacks, I decided to desolder the old one to save time. Ya know, there's not a darn thing wrong with it -- no cracks, leaks, nothing, even from underneath.

So I got to thinking about that HOT and in reading a Dokert post on how to test them and then Bob Roberts' page of things gone wrong with G07s http://arcadecontrols.com/BBBB/g07repair.html

I noticed that the two white plastic insulators that are supposed to guide the screws through the hole and isolate them were inverted. This yielded an offcenter mount since the protruding part of the white guides were not going through the holes. The emitter/base pins were close to the edge, but not touching which is why my ground tests passed, however the screws themselves WERE touching the inside of the hole -- which hopefully explains why 901 blew.

So, I corrected the HOT mounting and ensuring that it's still good (.50 volts CE and CB), which matches the other two I have. Soldered back in a new 901 and the existing flyback and going to give it a whirl. If this didn't solve the problem and the flyback is indeed bad, well, I'm getting good at soldering cap legs onto 20mm fuses.

I'd like to get back to the original B+ problem, hoping the cap kit fixed that.

Too late now for safety and going to fire this up in the morning.
 
Don't keep us waiting - what happened, man?!?!?

And what do you mean the inserts were inverted? You mean, they were on the wrong side of the frame?
 
Work called, that's what happened. Magic hour will happen at 4PM CST :)

From left to right you have:
mounting bracket, screw insulating white "disc", chassis, HOT

I'll post a picture later, but that insulating white disc is supposed to look like this

|
|]
|

with the ] going into the chassis hole to keep the HOT mounting screws from touching the chassis.

I had mine like this, with the fitting part facing away from the chassis:

|
[|
|
(grr, can't indent)


So the white insulator was sitting flush against the chassis, but essentially flipped. There's nothing preventing it from being installed this way and you end up with a lot of "wiggle" room since the mount isn't being locked by that white mounting piece. This can allow the HOT to visually appear mounted correctly (pins not touching the chassis), but yet the screws are. Still unsure as to why the continuity test didn't buzz, but I'm sure hoping this was why F901 blew twice and my flyback looks pretty darn nice.

-E
 
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