Wells Gardner W4800 Blowing Fuses

[Taco]

I just found out that this monitor is a Wells Gardner K4800. At power up it blows the soldered in fuse. I am a newb and this is my first attempt at monitor repair. Ive read just about everything I could find and just finished pulling the diodes (4) after the fuse and they check fine.

Latest check found u shaped retaining bar that holds the flyback onto the upper bracket burned completely through in the post that runs in the middle of the flyback (Top Pic).
Also vertical output portion of the board is really dark on the top as compared to the rest of the board. The solder side looks overheated in this area with white frost like color (Bottom Pic).
Was the flyback probably the culprit, and is this board worth saving?
I have more pictures, but can't post them bc it seems there is a limit to two photos. I can email them to anyone interested in helping further.

[StatFreak]

I have more pictures, but can't post them bc it seems there is a limit to two photos. ...

That is only because the software was crashing when we allowed more attachments. Just make back-to-back posts and upload as many pictures as you need.


StatFreak
  Global Moderator

[Taco]

Thanks..heres more pics

[Taco]

and the last two

[channelmaniac]

If the fuses are blowing check for a bad short.

Desolder the horizontal output transistor, take it out of the chassis, and check it for shorts with your ohmmeter. If it's bad, then you might have a bad flyback too... Although I'd suspect the flyback too seeing that crack in the plastic on one of your pics.

[Firebird]

I was thinking the same about the flyback, the crack coupled with the pic of the retainer being burned off.

[Taco]

Thanks everyone...

Im a newb at parts id, so could someone make a diagram with the parts and their nomenclature? Ive watched tons of videos and looked everywhere, and can't find that info anywhere. I've learned things like "HOT" meaniing horizontal output transformer, but identifying that part on the board, and how to use the multimeter to test it would be super. I love tinkering with these old games and getting them working, but I have to admit, i'm stupid on the use of the meter. For example...I wanted to build an ESR meter, so I bought the parts and built it, turned it on and it worked flawless, but tell me to check any of the components in it and i'd look like that kid that didn't study before the test.
I need the kind of help like heres a pic of what you are looking for, heres lead one,two,three now place your meter on ? and take the neg lead, hold it on ?, and take the pos lead to pins?, and if it reads?,then?....get my drift?
I'm sure that after I can learn whats what on these boards, then I will be ok.
I think someone would have a winning video on say utube if they took one of these boards and just started by naming each part from the power in side to the output of the flyback. I've watched countless hours of video trying to learn this, and just when they get to the meat of the board, they stop showing you anything, and then start talking like you already know how to fix it.

Now that everyone thinks i'm crazy...lol...does this board look savable? bc of the heated vertical output section?

Thanks everyone for your help God Bless Our USA

[channelmaniac]

HOT - Horizontal Output Transistor (not transformer) drives the FBT and gives you not only high voltage but also other sources of low voltage via taps off of it. Some other voltages it provides are: focus voltage and the voltage needed for the vertical deflection circuit

FBT - Flyback, Flyback Transformer

The HOT is usually a great big transistor on a big piece of metal that acts as a heatsink. They are usually very close (within mere inches) of the FBT. You can verify a big transistor is an HOT by either looking up the part # on it (http://www.datasheetarchive.com or http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search?OpenForm) or by following the traces it's soldered to as they will lead to the FBT.

[Taco]

Thanks

[midas touch]

Hey  Taco.....I've been following your post and Am right with you..I've had quite a bit of electrical training but very little electronics training...Enough to be dangerous. I went to hvac school so i know how to check caps and resistors ....you know the basics...any way keep asking questions and we are all learning from them......Mark