flyback or what?

[roboto]

Hey all.  I'm having quite some trouble with my Wells Gardner 19" K7000 series arcade monitor.  I've been trying to get it working for a while now.  I got a cap kit from Bob Roberts, and some pots when I finally found a remote pcb, new fuse(the only one I know of on the pcb) and put them all in.  But I still get nothing when I turn it on.  There is no glow in neck of the tube(there's supposed to be right?) -it just stays black and cold.  I figure it's not getting power.  So I got a test light and there is power coming from the iso transformer, running through the pcb, power on the neck pcb-but it still won't power up.  I know before I got it it was "burnt out" b/c some genius hooked it up w/o an iso. transformer.  But Bob Roberts figured a cap kit would fix it, and I hoped it would.   But it didn't.   Bob has since given me a few more suggestions-he is great-  he told me it could be:
1    Forgetting to put the yoke plug back on.
2    Fuse F1 blown even though it looks good.
3    A bad regulator STR30xx - check for voltage both sides of white
block
resistor
     mounted on frame.
4    An open white vertical mounted block resistor at R103 next to
biggest
cap on bd.
5    If it never had power up of any kind.... possible bad flyback or
HOT,
or both.

My problem is that I am not exactly sure how to diagnose these things-I don't just want to go out and buy replacements for all that and have it not work-I want to know what's wrong before I spend any more money.  Can anyone help me or tell me how to diagnose these parts-is a test light enough, or do I need more sophisticated equipment?  I understand electronics quite well, but I am no expert in testing.  Any help in getting this thing to finally turn on would seriously make my day!  Thanks a lot!!!
LIAM

[BobA]

While we wait for the monitor gurus maybe I can help a bit.  I would suggest a multimeter to measure voltages as a test light is not enough.   Will not let you measure the HV but will check your B+ and other lower voltages.  Also allows you to test continuity and test transistors when used properly.  The cost of a $20 multimeter will probably allow you to isolate the area of your problem.

There are troubleshooting flow charts for most WG monitors that you can follow with your meter in hand.

A multimeter will also come in handy when working on other pieces of equipment in the HOBBY.

BobA

[roboto]

Thanks for the reply Boba.  I have actually seen the Wells Gardner flowchart for my monitor.  I was confused because it starts off with the CRT filament-"CRT filament lit?"  I am assuming that the crt filament is the piece that the neck pcb connects to on the tube?  Then it says to check the crt circuit-but I can't do that because I don't know where it is!
:-(  So that is what's stopping me from following the flowchart right now.  But if you could tell me about the crt filament and/or crt circuit(nbt sure if it's the same thing) then perhaps I could get started, I hope.  Thanks a lot!!!!
LIAM

[BobA]

The crt filament is inside the neck of the tube and glows when it receives power.  I don't have the flow chart of the k7000 but the filament circuit icomes from the power transformer T1 to the neck board which connects to the back of the crt there is only a single resistor in the circuit.

I don't understand their reference to CRT circuit unless it is the neck board.   The wires and connectors are a source of problems for many monitors.  Typically a broken solder joint where the wires are not well supported.

First thing to do is make your basic power checks to see if there is any power or what voltages are missing or incorrect.

Bob

[MrArcade]

Here is the newer flowchart that is in more everyday terms

http://home.woh.rr.com/ultimatearcade/temp/K7000flo.jpg

I will leave this up for a day or two, so be sure to right click it and "save as".

The protection circuit may be activated...which will shut down the High Voltage to the monitor.  That is what was wrong with my 25" K7000.  The flowchart is the best thing to follow.  It will lead you right to the problem

[Dave_K.]

I'm not sure about the k7000 model, but the older WG monitors use 2 fuses.  Check your shcematic.

Scratch that...from the looks of MrArcade's flowchart, there is only one fuse.