Wells Gardner K7000, neck glow and no pic, recapped - No picture

[Honzo]

Hi everyone!
I'm new here to these forums mainly because i just came into ownership of cabinet.  I was driving home from work and spotted the gem sitting outside a putt-putt place so i asked the owner and he let me pick it up.  I have no idea of the history behind this machine (nor does the previous owner apparently, he didn't have the key to give me), but from the looks of it, it hasn't always been a Mortal Kombat II cabinet.  The control panel's underside has marks as if it used to have a different layout, the original switch on the top (whatever it went to) was cut, the marquee was very plain and lacking anything giving away what game it was (i didn't know until i actually leaned inside and read "Sound Rom Mortal Kombat II" off a chip on the board), etc.  Anyway, i originally planned on gutting it to make it a mame cabinet, but got caught up in the fascination.  After connecting some connectors that appeared to go together, i plugged it in and it booted to what appears to be a working state.  typical music plays, triggered a coin drop and it recognized it, was able to select a character by sound and all and it all sounded to be in working order... except for the monitor that is... so here are the symptoms:

1. No light, none whatsover, not even just black light as a crt tv would do on a video channel
2. No picture (obviously comes with the lack of light)
3. BUT, i do have that typical high pitched crt wine....

So i'm assuming its all in the monitor as everything seems to be in working order except it, but i honestly can't be sure since i have no history behind the machine

Also, if it helps, here are some numbers i found on a sticker on the tube:

Zenith
G-A63ADG25X
04RC0105-005
EIA 1101
OEM 26602

Thanks for any insight!

[Honzo]

Doh! 
Reread the sticky for this section, i found a sticker on the metal frame surrounding it saying model number 25k7131, and i think the brand was Wells-Gardner if that helps

[Ken Layton]

That is a Wells-Gardner k7000 series. Order a k7000 capkit, flyback, and horizontal output transistor (a.k.a. the deluxe k7000 rebuild kit) from Bob Roberts.

[Honzo]

Sorry, i don't mean to be helpless but i'm having trouble finding things on this site, can you give me a link? 

EDIT: AND.. (not to pester) but how sure are you this is whats wrong with the monitor?

[SirPeale]

Ken is suggesting the "shotgun" approach.  At this age, many flybacks are failing.  Your monitor certainly needs the capacitors replaced if they're orginal.

Of course, you can take the cheap way out - so far.  Remove the chassis and inspect it for anything obviously wrong - broken/cracked/melted solder, cracked PCB, loose connections, etc.  Repair as necessary and test again.

[Kevin Mullins]

K7000 Flyback Repair Kit    $26.00 + shipping (I think it's still about $6.00)

http://www.therealbobroberts.net/parts.html#flyback

[Honzo]

hmm, i'll take your word for it since i'm sure you all know what you're talking about.
I'll get on that after i discharge the tube and pull out the chassis and neck board.

[Honzo]

Ok, so heres the update:

Received my Flyback and cap kit, installed them without a problem, but its still a no go 
although i do at least have a glow in the neck now which if i remember is a good sign...
any ideas?

[grantspain]

on the flyback there are 2 controls(screen volts and focus),if you installed a new flyback then these will need to be adjusted
screen volts is a pre brightness
a glow from the neck is an extremely promising sign

[Ken Layton]

After installing a capkit and new flyback it is common that some controls will need to be adjusted/readjusted.

The "SCREEN" control on the flyback should be adjusted first. Consider it a "coarse" brightness control. The focus will be out of adjustment so you'll need to adjust that too.

[Honzo]

well i've toggled the SCREEN control all the way and i didn't get any white screen ever... 

[grantspain]

did you put the the wires in the correct place on the crt card?

[Honzo]

what do you mean by crt card? the neck board?
as far as wires go, i'm nearly certain everything is plugged in where it needs to be 

[Honzo]

also if it helps, i noticed i see a few random white/blusish flashes across the screen every now and then. they're kind of rare though... but other than that, no light from the screen, and no real turn off flash....

[Kevin Mullins]

Do you get the high voltage crackle/static sound around the tube when it first fires up ?

[Honzo]

yep, sure do

[Ken Layton]

Yoke plugged back in?

On the new flyback there are two "flying leads" (wires) that go to the neckboard. The heavier of the two is the focus voltage (8,000 volts) and connects to the tube socket on the neckboard. NO SPLICES ARE PERMITTED ON THIS WIRE. The smaller wire goes to the screen (G2) push on terminal on the neckboard (approx 400 volts).

There are TWO black ground wires soldered to the heavy ground foil trace on the neckboard. One of those black wires has a ring terminal crimped on the end of it and it is bolted to the aluminum frame near the flyback. The other black wire goes from the neckboard to the stretched spring that stretches across the lower black portion of the picture tube. Both of these black wires must be reconnected to where they were.

If everything is reconnected and a video signal is indeed connected at the monitor's video input connector then there should be a picture of some kind. The screen control is the bottom control on the flyback and the focus adjustment is the top control.

If still no picture then time to get out your high voltage probe and measure the high voltage. The voltage can be between 19,000 and 24,000 volts. Any higher or lower and you've got a problem. If the voltage climbs real quick (or goes to 30,000) and drops down to zero then the B+ regulator is probably bad.

[Honzo]

I followed the two flying leads from the old flyback and ensured the new ones went the same place, the heavier one went to the connector that plugs into the neck (i'm guessing this is the tube socket?) and when i was investigating, it just slipped right out but there was a little pressure so the new one slipeed in and was secured.  I'm assuming there are metal pressure plates of some sort in there that hold it in? anyway, if so, thats connected right, and for the other flying lead that goes to the push on terminal on the neck board, i cut the previous cord and left an inch of old wire, stripped it, and soldered the new flying lead to it and heat shrunk it, is that ok?

as for the black grounds, i think i know what your talking about, but i'll have to double check tomorrow, but it looks like someone had cut one of them and the other was twisted and grounded to the earth wire around the tube?.... i'll try to get some pictures up , but all my cameras are old and garbage, but i'll try

[Honzo]

ok, rechecked everything and all cables are properly plugged in, including the two grounds.  as for probing for the voltage, will any multimeter work? if not, which one do i need? and which two points do i probe for the voltage?

EDIT: also, i noticed the Horizontal position pot is no longer fixed, it will free rotate in both directions unlike the rest of them, could this mean that it needs replaced and could this be my fix?

Another EDIT: What are the chances the tube is totally shot? I don't want to pour money into a board that isn't going to do anything, at some point I'd rather just buy a tv and build a bezel to make it look nice .  I would like to fix it though since it fits the bezel so nicely 

[Honzo]

bump. Any answers to my questions?

[grantspain]

i am not sure what a broken position pot would give you but i doubt it would stop any picture from appearing-i guess it would make sense to replace it though

[Honzo]

hmm, ok, what do i probe for voltage though? what two points? i'll do that first and if it's irregular, i'll see where to go from there