zenith 25" monitor

sabercatt

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so I picked up a project golden tee 2005. looks like someone replaced the monitor with an older zenith. the zenith is not wired up and is labeled for an isolation transformer. before ordering a transformer, I was wondering if the aux output of the happ power pro 20 is isolated. it shows a 3 pin aux out that is listed as 2 amp max. here is the power supply:
https://na.suzohapp.com/products/power_supplies/80-0002-10
 
so I picked up a project golden tee 2005. looks like someone replaced the monitor with an older zenith. the zenith is not wired up and is labeled for an isolation transformer.

before ordering a transformer, I was wondering if the aux output of the happ power pro 20 is isolated. it shows a 3 pin aux out that is listed as 2 amp max. here is the power supply:
https://na.suzohapp.com/products/power_supplies/80-0002-10

I think you are confused a bit

you need a iso transformer.... psu don't have them built in, its a separate device

iso are 120v in / 120v out

goes like this

120v to line filter. from their pair goes to pwr dist block
from the dist block to the psu and another to > iso


this is what a iso may look like
 

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at the time I took this photo, I didn't wire the iso up since my monitor didn't require it. I laid out what I recycled from the
cabinet according to what was on hardMVS ( thy referenced bob roberts )

vMJzMEq.jpg


this may be whats typicaly found inside game cabinets ( some may have different looking components ) I just cleaned mine up a bit.

I'm sure others will chime in but layout shd be same or similar
 
ok, just wanted to make sure before I ordered and iso that the ps didn't have one built into it. thanks! now hopefully the monitor actually works.
 
how do you know you have a zenith chassis?? (K7000A??) or are you just reading the sticker on the tube which represents absolutely nothing as to what model of chassis. i would post pictures of the chassis just to be safe because not all chassis require an iso and you never want to assume.
 
how do you know you have a zenith chassis?? (K7000A??) or are you just reading the sticker on the tube which represents absolutely nothing as to what model of chassis. i would post pictures of the chassis just to be safe because not all chassis require an iso and you never want to assume.

He likely has a zenith tube and a K7000 with the sticker still on it that says it needs and iso-tranformer.

Yes, some of the sticker really didn't fall off! (Most of them seem to though.)
 
here's what I managed for pictures in the dark. thought I saw something that said 1992.
 

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here's what I managed for pictures in the dark. thought I saw something that said 1992.

I see the 2 pprong connector you mentioned before. not very good shot of the chassis but that is/looks to be the power to the monitor. you would have to connect that to the iso transformer
 
That does look like a K7000. I can't tell which variant by the pictures. Another member might be able to do that.

You DO need an isolation transformer.

Any arcade isolation transformer should work. 100watts is what you need. (1amp or bigger.)
 
here's what I managed for pictures in the dark. thought I saw something that said 1992.

yes that is the wells gardner K7000. its one of the odd ball ones with the vertical pcb and second width coil, but still WG K7000.
 
got a molex connector on it as well, so I assume they were powering cab lights or something else downstream behind the isolater. is this a low res or med res monitor?
 
got a molex connector on it as well, so I assume they were powering cab lights or something else downstream behind the isolater. is this a low res or med res monitor?

CGA/standard res (low I guess).

It has a 2 pin molex connector on it from your picture. Leave the connector on it as it should match the output of the isolation transformer you need.

The input in the isolation transformer should be a 3pin molex connector (hot/neutral/field ground) that plugs into your A/C wiring. Some will just have the 2pin connector like your monitors and you have to run the field ground wire (green) to the base of the transformer, typically to one of the screws, with a ring terminal/connector.
 
got the isolation transformer installed today and dead screen. looks like flyback is cracked across the middle of it.
 

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oh, I thought black knob flybacks don't fail. :rolleyes:

dead K7000 can be any number of things. you'll need to measure voltage at the large ceramic resistor hanging off the side. your meter should be set to 200V range DC, black probe you can hook into one of the holes of the heatsink wall for ground, and touch the red probe to the leads of the resistor. under normal operation it should be like 160V (unregulated) on the tube side, and 130V (regulated) on the side closest to you. given that you have nothing, I will venture you'll see about 170V on both tabs, and the monitor will be in high voltage shutdown.

while it's plausible this could indicate a bad voltage regulator, it could also be caused by a shorted HOT, so now turn your meter to diode test, with the cabinet completely turned off, black probe in the heatsink wall, and touch the red probe to the middle leg of the HOT (this is the transistor mounted to the L-shaped portion of the heatsink behind the flyback) ... if it reads a 0.00, the HOT is blown. alternatively you could do resistance test, low resistance it's blown, high resistance it's good.

oh, often times you'll find a chassis missing a fuse too. so verify the fuse is installed. :) some chassis versions are silked 1.5A, others 2A, you can use 2A slo-blo on either. if the fuse is blown, which it probably is with a flyback failure, you can probably bet on the HOT being toast regardless.

I'm giving you the complete test procedure to do when you have a dead K7000. I would encourage new HOT, flyback, and voltage regulator (this is the STR part tucked in the corner near the fuse, you need to match the exact part number as there are 2 varieties and they're not compatible with one another. additionally, I'm assuming you have a 25" chassis with the add-on card, but the 123/130 parts also matter, as the 123 is for 19" chassis, and 130 is for 25" chassis)

if the fuse is blown, like I assume it is, I would start by replacing the flyback and HOT. be certain you either reuse the old mica insulator (the clear plastic part that sits on the back of the transistor) or purchase a new one with your other parts. thermal paste, the white kind, not arctic silver, should be applied. and obviously, you'll need a new 2A slo-blo fuse, so be sure to have those on hand as well.

if the flyback and HOT don't bring it back to life, you'll have to repeat the side resistor test above -- if you're getting above 160V on the regulated side, then the voltage regulator is bad and will need to be replaced next.

if these repairs are beyond your scope, you can send it to anyone to get fixed. you've probably heard horror stories about flyback anodes and the electricity they can hold in the tube, your chassis is dead, so don't even worry about it.

that's all. good luck.
 
on the 2nd picture you just posted...why isnt the small connector with the blue and white wires plugged in?

almost every original flyback i've seen (probably 25+ of them) is cracked like that, doesn't mean it is dead. you should still replace it though.
 
I unplugged the blue/white connector while I was removing it, until I figured out to just pull the board off the neck.

as for the fuse, it is fine and had good voltage through it. i'll check the other things mentioned. is this able to be bench tested or do I need to have it hooked up to the monitor?
 
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