Fuse Blown After Transporting CRT Monitor

Where does your brother keep his coins ? Any chance that your brother's premises are wired to a different voltage ?

My brother's house uses the same voltage as mine 120v. I'm in NewYork while he's in New Jersey but both are in the U.S. with the same line voltage.

Anyway, he returned the monitor to me where I replaced the fuse only to see it blow again, so that's not at issue here.

I did find a loose screw inside that I did remove. There was one missing for mounting the metal shielding just inside the plastic shell so that accounts for this. I had hoped that this would explain the short-circuit but I ended up blowing yet another fuse anyway.

This monitor is much too large to be able to be shaken with ease so as to listen for any loose items rattling. I DID stand it up on different ends to see if this MIGHT happen but no. This thing is built pretty solid.

BTW, the m> >

if the unit was taken from a cold van into room temperature and switched on, condensation may have formed and shorted the power supply rectifier or HOT. you'll need to see the repair faq for trouleshoting this one:

READ and observe the vital safety info as there are lethal voltages in these sets even after the plug has been pulled.

-B.

The screw probably shorted something and blew a part in the power supply. If the fuse blows immediately I'd start by checking the rectifier.

It's quite possible this screw may have shorted something out within the power supply but I think that it is unlikely. The power supply has it's own metal cage and, when I disconnect all of the cables, can be completely removed from the monitor. Also, its PC board is positioned in a vertical orientation when mounted within the monitor while this is normally standing. The screw wasn't likely touching inside there. The scarier possibility is that it shorted out something near the flyback transformer.

Now that I think about it, disconnecting the cables will isolate the power supply from the rest of the monitor. This should allow me to see if the power supply is still working properly by itself. Or at least not blow another fuse.

What risk would I take for creating further damage to the monitor if I were to play with this?

There are four connectors to the power supply. Five, if you include the AC power cord. Two are for ribbon cables which are most likely for low-voltage stuff such as logic chips. The other two are for heavier guage wiring obviously for high-voltage stuff. Of these, one is a two-pin connector while the other is a four-pin.

you need a load on the power supply . don't try to connect it without one or it'll probably die ! replace any obviously shorted components, put it back in the set and power up with the 60w light bulb in place of the fuse as per the FAQ. Beyond this there's little you can do if you aren't exp=E8rienced in this work. May be easier to get another monitor as there are planty of cheap used CRTS around these days for peanuts.

-B