Is it safe to discharge CRT anode cap with a magnetized tip screwdriver?

[TheQuick&TheDeadass]

I went to three different hardware stores today looking for a cheap, long, flat blade screwdriver to use for a CRT discharging tool. Every single one of them sold only screwdrivers with magnetized tips, and many of them were "all metal core" as well. It's like going to the store to look for a frying pan, only to find that all they sell are non-stick pans with toxic forever chemicals. Well, I went on Amazon, and all the generic single screwdrivers were like 10 times the price. I also couldn't tell if they were magnetized or if they had all-metal cores.

I was under the assumption that sticking something magnetic under the anode cap would be very dangerous. Is it safe to use a magnetic screwdriver or not? Nothing online I found about discharging CRTs said anything. Does anybody have personal recommendations for what they use with links? I'm practically ready to break down and spend hundreds on the B&K HV probe.

[jd213]

I believe a magnetized tip will still conduct electricity, maybe not as well though. You might be able to find one without a magnetized tip in a discount store.

[Josh128]

If its magnetized, its conductive. Check the resistance between the tip and the shank/shaft, if theres continuity, its fine.

[TheQuick&TheDeadass]

I believe a magnetized tip will still conduct electricity, maybe not as well though. You might be able to find one without a magnetized tip in a discount store.

That's not what I'm asking. I'm asking if there's any inherent danger in using a magnetized tip vs a non-magnetized tip for discharging the anode cap? Will it cause it to arc out or anything? None of the guides online are clear. They just say "use a screwdriver with a rubber handle". They don't specify which type of tip. I don't want to die just because I used the wrong type of screwdriver.

[Josh128]

That's not what I'm asking. I'm asking if there's any inherent danger in using a magnetized tip vs a non-magnetized tip for discharging the anode cap? Will it cause it to arc out or anything? None of the guides online are clear. They just say "use a screwdriver with a rubber handle". They don't specify which type of tip. I don't want to die just because I used the wrong type of screwdriver.

No, it will not cause it to "arc out". The anodes voltage is relative to the cathode, so no matter what material you use, magnetized or not, to connect the two, the current will flow from one to the other through the material connecting them until the voltage between the two is 0. The current will always take the path of least resistance, thats basic DC electricity. Not understanding that makes me highly recommend you not attempt to work on CRTs yourself, but in case you do anyway, below is the basic gist.

Connect a wire , preferably through a voltage rated drain resistor and inductor to limit arc and current flow, from the grounding strap on the back of your tube to the metal shank of your insulated handle screwdriver. Im assuming you dont have a proper resistor/inductor arc snubber setup, so be prepared for a loud "SNAP" when you dead short the two with just a wire.

[TheQuick&TheDeadass]

Not understanding that makes me highly recommend you not attempt to work on CRTs yourself, but in case you do anyway, below is the basic gist.

I will admit I am not really qualified to work on CRTs at all. However, I am the only person in a 50-mile radius who gives a shit about CRTs. Everyone who used to repair them is either retired or dead. All I can really go off is the various safety protocols posted online. If I don't see anything that says "magnetic tip screwdrivers are safe to use for discharging CRTs", then I will just assume the worst about them.

[Syntax]

If you haven't done it before best advice I can give is use 1 hand.
That way if you shock yourself its not so bad as most the time the path will be from hand to foot down the side of your body.
2 hands is asking for a shock across the chest, and when that happens you'll know it lol.

Oh, and discharge it a few times, some like to hold/rebuild charge and try to trick you.

[TheQuick&TheDeadass]

Thank you for the advice. I was aware of the 1-handed method from various CRT discharge safety guides.

I decided to just go with the B&K Precision PR 28A tool because I was having trouble even clipping one end of the alligator clips to the screwdrivers of various shaft diameters I already own. I figured it's better safe than sorry, and the tool will eventually pay for itself.

[Syntax]

I use some wire + resistor on the end of a chopstick, using a screwdriver and scratching up the coating is poor form IMO.

[TheQuick&TheDeadass]

I agree. The main two tools I see recommended are either a professional HV probe or a screwdriver with a method of grounding it to the chassis. I couldn't find any actual insulation ratings for any of the probes out there, so I assumed they were not much safer than just using a cheap screwdriver with a wire and a clip. In my tests with the clips, it was very easy to shake the clip off even the thinnest screwdriver with basic movements. I am aware that many people tie stripped copper wire around the screwdriver, or maybe even secure it with electrical tape, but I'd rather have the peace of mind.

[DejahThoris]

the tool will eventually pay for itself.

100s of monitors across my workbench and I have never felt this was worth the money. I've never seen how it could pay for itself with as much work as I do, and I do not see how it'll ever pay for itself in your case, especially since you're not anywhere near where you would need to be as far as knowledge and experience to do this for a living (and apparently live somewhere where there's 0 demand for the service).

If you want to use it because it makes you more comfortable, sure. But how is it going to pay for itself?

[matt]

100s of monitors across my workbench and I have never felt this was worth the money. I've never seen how it could pay for itself with as much work as I do, and I do not see how it'll ever pay for itself in your case, especially since you're not anywhere near where you would need to be as far as knowledge and experience to do this for a living (and apparently live somewhere where there's 0 demand for the service).

If you want to use it because it makes you more comfortable, sure. But how is it going to pay for itself?

My HV probe has totally paid for itself. I've used it often to check anode & focus voltages for flyback substitutions. The net value of those monitors was far greater than the cost of the probe.

Is it worth it as a discharge tool? Not for most people and TBH I mostly still use the one I made from a screwdriver.