View Single Post
  #10  
Old 05-28-2019, 03:26 PM
old_tv_nut's Avatar
old_tv_nut old_tv_nut is offline
See yourself on Color TV!
 
Join Date: Jul 2004
Location: Rancho Sahuarita
Posts: 7,745
Quote:
Originally Posted by Electronic M View Post
To add to this a bit if you start to do regular service work on TVs where you need to turn the set off and pull the chassis or main board quickly after power off then you want to put a 1M resistor in series with your screw driver to ground lead. If there was a lot of charge stored in the CRTs integral capacitor (which is the case imediately after power off) shorting to ground without a series resistor can cause the HV charge on the CRT to bounce back in a few moments.

Early on in my TV resto work I didn't know about that and kept getting HV bites from my Silvertone Roundy...Cussed like a pirate over it a bunch then learned about bounce back and made sure to only resistively discharge after that.(though I'll still short discharge if I'm in a situation where I don't have what I need to resistively discharge on hand)
I didn't know that using a resistive discharge would prevent the bounceback (dielectric relaxation) - interesting. I wonder if bounceback would be eliminated with a direct discharge if you just held the contact for a few seconds more?
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany
Reply With Quote
Audiokarma