G07 F901 blown, X01 pins short = Fly-back dead ?

[Level42]

Hi, I've searched the forum and google.....just a quick question.

The G07 on the Centipede I just bought is dead. F901 is blown. So I checked X01. The resistance between chassis and the case of that transistor is about 7k. Between the pins a full short (0,3 Ohms). Does this automaticaly mean a bad Fly-back ?

I don't see any cracks on it...just the regular dust...

[Grauwulf]

It's likely, but I have had a few G07's where the fuse was blown and I have just replaced the fuse and it's fine. I have also had a couple of G07's where the flyback was bad and wasn't visibly split.

So I guess what I am trying to say is...replace the fuse, if it blows again, replace the flyback.

[woodygjw]

I had the same thing a few weeks ago on my centipede with a G07(bought it without monitor working).  F901 blown, couldn't find any cracks on the flyback, but my X01 was OK.  Replaced the fuse, monitor fired up for about 1 second, then blew the fuse again.  Then i could see a crack in the flyback.  So I went ahead and replaced all above listed parts and capped it, works great now.

[Level42]

Thanks ! So what resistance do you guys measure between the legs (pins) of a good X01 (while it's in the monitor) ?

[grantspain]

depending how you fuse blows helps you to narrow down the fault.
fuses that blow crapless on power up usually points towards a dead short on the primary side of the power supply whether it be the p.t.c,diode/bridge rectifier,trapped degauss coil,incorrect input voltage,replacement component leg not trimmed etc
if a fuse parts slightly then that could point towards a problem further in the chassis,maybe some kind of voltage regulator problem but normally a problem at this point will just cause a monitor to shut down into trip
of course its always worth double checking you have the correct type and rated fuse in the chassis(i fixed a chassis last week that had a 2 amp quick blow instead of anti surge and it blew the fuse 3 out of 5 power ups)

[woodygjw]

Thanks ! So what resistance do you guys measure between the legs (pins) of a good X01 (while it's in the monitor) ?

I can't get to it in my centipede right now to measure.  I have a chassis that I have not tested yet and it reads low between the pins also(in circuit).  Set the meter to diode check, ground your meter to the metal chassis, put your red lead on the metal case of the transistor, high or open it is likely good, shorted it is bad.  I think your flyback and/or transistor is bad.  That is what was wrong with mine, in a centipede as well.  Looks like you, me and RayB have had some bad luck with centipede's, although I guess we did buy them this way