Lead a noob thru a dead G07-907?

joemagiera

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Anyone willing to lead a monitor noob thru a repair of an Electrohome G07-907? I have a known good 120VAC source and a known good signal source. Monitor has no signs of life, no neck glow, no hum, no noises or static when turned on or off, nothing, dead.

First step(s)? Feel free if you just want to try it by email too. Thanks in advance.
 
First steps

It has been said you cannot kill a G07 chassis. Everyone will tell you cap kit and a flyback are the first things to be done. Most of those suffer from a dead flyback first so do those and touch up all the solder and see where you are. Good to see another back from the dead so keep at it!
 
Let's start with basics... The 120VAC source is isolated (via isolation transformer), right? If not, the monitor may be damaged from that.

If it is on isolated power, is the fuse good?
 
Well, I'd try discharging the small fuse (both sides) first before I tested it...

Yeah, but you would pull the chassis first too.

So let me clarify... If you have pulled the chassis, make sure to discharge both sides of fuse F901 before testing and make damn sure you don't touch the legs of the filter cap.
 
I disharged a filter cap 2 weekends ago where the 901 fuse was blown and it had been sitting for a bit and it still let out a pretty good bang. Be careful !
 
Test fuse F901 & F902, report back with results.

Ok, this will give you a clue as to how much of a noob you're dealing with. I tested F902 inline and found it to be good. F902 is right be where the 120VAC comes in (and I do have an isolated supply by the way). I can't find F901. I didn't take the chassis off the frame, so maybe it's underneath? Doubtful as I don't ever recall a fuse on the underside of a monitor before, but I swear, I looked at this thing for 10 minutes and don't see another fuse on the chassis. There's a silver shield type thing that's about 1" x 2" (one side cut on an angle) that's covering a bunch of components. Maybe it's covering that fuse? Can anyone point out where F901 is on the board?
 
F901 is right next to the big grey capacitor.
ImageUploadedByTapatalk1305679448.713941.jpg

As you can see in the pic there are 2 fuses. The one down the bottom is f902 and the one up near the top of the pic is f901. Fuse size may differ but the rating should be the same.

If you take the chassis off the frame you will be able to see the labels underneath the chassis. Much easier.
 
The most common failure mode of the G07 that results in a dead monitor is the flyback. The flyback fails, and starts to draw too much current, destroying the horizontal output transistor and eventually blowing the B+ fuse - F901. If that fuse is blown, plan on replacing the flyback, HOT, fuse, and while you've got it out, there's no reason why you shouldn't recap it as well.

-Ian
 
It may not be that large Joe, the one's I have seen are about half that size and mounted down next to the PCB. Or maybe you have a space there where someone pulled out a blown one.
 
first thing i suggest is to pull the chassis from the monitor itself. that way, you can see all the components (not to mention you have to pull the chassis if you replace anything). BE SURE TO DISCHARGE THE MONITOR FIRST!

you may not have a F901, but its supposed to be there. i suggest ordering a G07 repair kit from bob roberts ($28, http://www.therealbobroberts.net/parts.html, second item down). that covers a flyback, hot, fuses, and caps - all the major components. im not sure how much of a noob you are, so this is assuming you know how to solder.
 
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