> >From the "Full of Mac" website: (SE/30) > > 5. Bleeder Resister and Flyback Transformer > The high voltage (1,500 Volts) on the anode of the CRT is supplied by the flyback > transformer on the analog board. Do not touch the flyback transformer. Do not touch > the yoke assembly, yoke cable/connector, high voltage cable and anode connector, > either. > > Several flyback transformers have been used for compact Macs as shown Table below. > Normally, Macintosh SE/30 contains a flyback transformer with a built-in bleeder > resistor, and it automatically discharges the transformer, i.e., CRT when the power > is shut off. However, old and/or used SE/30s may have been modified or repaired. The > flyback transformer may be replaced by an older version. Thus, for your safety, you > must perform CRT discharge procedures.
Sigh. Here we go again with well-meaning, but emotionally based, advice. That site has some factual errors. The HV on the crt anode is about 10x higher (I typically measure 11-12kV, not 1500V). And it's not the transformer that would need discharging, it's the crt itself (it contains an integral HV capacitor, formed by conductive coatings on the inner and outer surfaces). The danger from a compact mac's HV discharge is *extremely* small, as long as the mac is not plugged in. Being the discharge path is certainly most unpleasant (unless you're into that sort of thing), but it's not particularly dangerous. As Jeff Walther's experience shows, advocating that everyone routinely discharge the HV for no good reason actually exposes more people to this "danger" than if folks just left it alone. I won't go further, other than to link (again) to my more detailed writing on this subject at http://www.applefritter.com/thefritter/13/drwebster.html. -- 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 ph, -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> The FAQ: <http://macfaq.org/> --> 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 ---------------------------------------------------------------
