> >Did you check the picture tube? sounds to me like that is the problem. But > >just my guess. Hey did you check any fuses? > > > >Josh > >----- Original Message ----- > > Well, I don't have a pin-out to know which pins are the filament - > which is what usually breaks when it gets dropped. Know where I > can find that info? I checked all the fuses and a few voltages > at some obvious test points but I don't have the tester to check > the HV plug on the tube...I've worked on TV repairs in a former > life...
Since you've worked in TV repair, then this trick is for you (others should ignore this unless you know what you are doing, because it involves sticking your fingers and face into the guts of a powered-up machine). To check CRT HV without actually exposing any HV connections, and without having to own a high-voltage probe and meter, just grab a small neon bulb (like a type NE-2 or NE2H; Radio Shack used to sell these in pairs, but I haven't checked in 10 years...), and hold it near the HV wire. It should glow brightly as you get to within a few mm of the surface. The bulb can have its wires broken off; you're directly exciting the neon gas with the HV RF field around the wire. If you're a very cautious/nervous type (and who wouldn't be?), tape the bulb around the end of an insulating rod (old toothbrush works great) and use that as a probe. If it doesn't glow, or glows only feebly, you don't have enough HV to light up the CRT. As for checking the filament, you can also do that without opening any connections or even knowing the pinout. Turn out the room lights, and look at the base of the CRT, where the socket/pins are. You will be able to see a glow there (orange-reddish) if the filament (and filament power supply) are good. [Otherwise, if it's a monochrome crt with a 9-pin base, the filament pins are almost always on pins 4 and 5. I didn't take note of your original posting, so I don't know if it is a monochrome FP display; sorry if it isn't] Hope that helps some. Good luck! --Tom -- Prof. Thomas H. Lee Center for Integrated Systems, CIS-205 420 Via Palou Mall Stanford University Stanford, CA 94305-4070 http://www-smirc.stanford.edu 650-725-3709 voice, -3383 fax -- Compact Macs is sponsored by <http://lowendmac.com/>. Support Low End Mac <http://lowendmac.com/lists/support.html> Compact Macs list info: <http://lowendmac.com/lists/compact.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive:<http://www.mail-archive.com/compact.macs%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
