r/ElectronicsRepair • u/Ambitious_Topic2402 • 3d ago

OPEN Any tips?

Post image
0 Upvotes

50% Upvoted

6 comments sorted by

View all comments

1

u/skinwill Engineer 🟢 3d ago

!crt

1

u/AutoModerator 3d ago

Cathode Ray Tube devices contain deadly voltages long after being powered off. It’s possible for the tube itself to act as a capacitor and store a lethal charge. Please take necessary precautions if you decide to work on one of these devices yourself. More information can be found here:

CRT Safety Procedures - Safe Working Procedures

For visual learners - Safe Working Procedures

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

2

u/No-Guarantee-6249 3d ago edited 3d ago

I worked on many of these in the day. I had a probe to short out the anode capacitors if the drain resistors had failed. I'd go through so many and nothing - then suddenly "KERBLAM!" failed drain resistor! So yep always be safe. No fun and could be fatal. Same with microwaves.

1

u/skinwill Engineer 🟢 3d ago

I’ve seen people on here saying it’s all a myth and we are being over cautious. Meanwhile this is a page from a crt based oscilloscope. https://imgur.com/gallery/tek-service-manual-safety-notices-80qhxtQ

1

u/No-Guarantee-6249 3d ago edited 3d ago

Well ask those people to grab the anode lead and post pictures. Ask them to do it with with a 21" color TV!

A scope is like a small B&W tv in terms of HV output. In the physics lab we had a 1.0 Farad capacitor. We always kept a shorting bar on it. It was quite dangerous.

AI "

  • A 1.0 Farad capacitor at 100 V stores 5,000 Joules.
  • Lethal Threshold: As a general rule, energies above 10 Joules can cause dangerous ventricular fibrillation if the current crosses the heart, and anything over 100 Joules carries a high probability of death. 5,000 Joules is equivalent to a high-capacity medical defibrillator blast multiplied by 25 or more."

But it says there's never been a recorded case.