K4900 Fuse Blowing

SkippyJoe777

Member
Joined
Mar 10, 2010
Messages
305
Reaction score
4
Location
Washington
Have a WG 4900 monitor with a strange Xformer and Cap attached to the side of the cage that I have never come across before. Has anyone seen this before? Why are these here? Also having a problem with the fuse on the Chassis blowing, I recapped the chassis and and did not physically see anything wrong while doing it. It blows with or without this odd Cap and Xformer connected.
 

Attachments

  • Sell 002.jpg
    Sell 002.jpg
    40.8 KB · Views: 46
  • Sell 001.jpg
    Sell 001.jpg
    46.6 KB · Views: 52
i would trash that cap.

then make sure your running the monitor correctly thru that iso

make sure your V.R or H.O.T are not shorted. and test all the diodes in the power supply section D501-506.

go over your work to see if you have any solder bridges.

also why is your power cord running thru the the space between the neck board and the card board????

Peace
Buffett
 
What's stamped on that transformer? I can read "sec.", what's the rest of it? Are two of the wires from that transformer attached to the neckboard?

Maybe a little 6 volt transformer to power the heater???

Edward
 
Xformer value

The Transformer reads SEC / 12.6 Volt / 3 Amp. It is fed from the 120V input to the Chassis and goes to the neckboard. It is the first monitor I have come across with this Mod.

Will try some of the troubleshooting suggestions today. Thanks guys! I have so many projects on the table right now if I cannot figure this out quick, I will have to outsource and have someone else repair it. Who is the man to send it to? It is already recapped just needs to be troubleshot, and the faster the turnaround the better!
 
Looks like someone had some chassis issues and tried to create the +12 needed for the neckboard drive transistors. Unfortunately, that 12v should be DC, not AC.

Doesn't surprise me that you're blowing fuses. Trash that transformer and cap. remove the extra wiring, and start rebuilding the chassis from scratch...
 
Back
Top Bottom