Testing a Monitor in Unknown Condition

D-Roy

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As I type this it sounds like a no-brainer question, but here goes:

I have a WG k4600 that the previous owner says is broken. Is it OK to power it up to test it or should I not even bother and move on to the usual cap kit/reflow the joints? Basically, am I going to make anything worse by powering up the monitor in this unknown broken state? It seems like I should at least power up to check voltage, neck glow, etc.

When I asked the owner if he knew what was broken he made a general statement about the neckboard needing something (don't recall what exactly). I got the feeling he didn't really know though. I haven't pulled any of the boards yet to check condition. Some of the neckboard solder joints possibly look suspect (to my rookie eyes).

Pics would help so I'll try to post some later.
 
I would suggest powering it up on your test bench and checking the picture and power levels. Also, with a 4600 I wiggle the daughter cards to see if anything changes.
 
Any damage that would have been done by powering it up, has already been done by your friend powering it up and finding out it doesn't work. Drag out your testing iso and give it some juice.
 
Yeah, power it up and check it. It'll let you know how bad it is right now, and what you need to do to fix it. Obviously, don't forget the isolation transformer!

Chances are, you need to resolder the daughter cards and their connectors, and cap it...

-Ian
 
This is what I do with an unknown chassis:

1) Clean as much dirt/dust off as possible.

2) Inspect entire chassis fotfr any obvious issues - blown caps, burnt parts, loose wires, blown fuses, missing parts, etc.

3) Inspect known problem areas for cold solder/broken traces.

4) Use meter to test fuse, VR, and HOT, as well as any common parts that short (such as C36 & C38 on K7000). Replace any that are bad.

5) Check flyback for any cracks. Replace if necessary.

6) If I REALLY need it to work, I'll put a fresh cap kit in before I test, just so I know that isn't an issue.

7) If everything looks good after that, then I plug it in and see what happens.

9 times out of 10 it works great after my previous steps. Doing good prep work beforehand greatly increases your chances of a working chassis, and doesn't really take that long. A lot of the chassis' sent to me for repair end up getting fixed before I ever put them on a tube....
 
OK, getting ready to hook this up, one last easy question(s) regarding the AC wires at the monitor. The AC wires that are coming out of the board/monitor are cut about 5 inches out and then are spliced to wires that end in a molex type connector. This is normal I assume.

I'm hooking this up to new power supply, iso, etc. Should I update the wires going into the monitor? Or just remove the old spliced wire portion and splice in the new wire that will go to iso? Or leave all that wiring and just put on a new molex connector that will mate up to my new iso wires?

That might have sounded confusing....

Thanks again.
 
The 4 WGK4600 monitors in my cabinets have about a foot of A/C cord coming from the chassis and terminating into a molex connector, none have been spliced.

If it is a neatly done splice job(soldered and heat shrink tubing, splice connector, etc.), I would leave it. But I like having the A/C monitor cord with a molex connector going to the iso.

You could take your meter and check continuity from the pins in the molex to the A/C solder points on the chassis. Then you know for sure you will have isolated a/c going to the chassis.
 
OK, getting ready to hook this up, one last easy question(s) regarding the AC wires at the monitor. The AC wires that are coming out of the board/monitor are cut about 5 inches out and then are spliced to wires that end in a molex type connector. This is normal I assume.
There are a couple different 2-position connectors that you'll commonly see on monitor AC wires. You usually see this kind of split job (or wire nuts, or twisted electrical tape) after a previous owner has transplanted a monitor into another game and had mismatched connectors or no connectors at all.

I'd put a Molex 0.093 2-position (link) on the monitor and cabinet wiring so it's easy to remove in the future, but do whatever works for you. Female on the on the monitor side, male on cabinet side is standard if I'm not mistaken.
 
OK, I couldn't find info if it matters which wire of the 2 iso wires goes with which of the 2 wires going into the monitor? I see where the 2 monitor wires goes into "MQ" on the chassis board, but I couldn't see any other markings for clues other than MQ.

Monitor/ISO power 101, I know, but I just want to make sure I can't wire this up backwards or anything.

Thanks!
 
Got it. That is what I thought, bu I've been reading so much monitor stuff lately I'm starting to second guess myself on stuff.
 
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