Apple ][e Fireworks Display

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Re: Apple ][e Fireworks Display

Postby Clym5 on Tue Jan 20, 2015 9:46 am

Gibsaw wrote:He was implying that because the caps are faulty they shouldn't be storing any charge... It will be the main filter caps that have probably died.

The high voltage caps may be fine. I would still proceed with caution.


Waiting for the HV caps to discharge would take too long. That's what I mean. If you really want, I guess you could short out the filter caps with a insulated screwdriver first if you really want.

There is no difference between a ][e monitor and a normal CRT in terms of safety. There are HV caps, a flyback, etc. The HV caps will store a very painful charge for months.

I've probably done more harm than good in this thread!
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Re: Apple ][e Fireworks Display

Postby RonTurner on Tue Jan 20, 2015 2:01 pm

Gurner wrote:By the way – WHY is it safe to open-up a ][e green screen monitor without waiting like with other CRT monitors?

Does this mean you can touch everything inside safely??


I have never waited and im still alive, I mess with 240 volts all the time and I cant tell you what it feels like to get a shock because I aint been shocked yet but appearantly DC is the most dangerous.

I have opened many PSU straight after power up and touched the capacitor pins etc, never had a shock ever! maybe im just lucky? Im guessing the coil and other components risistors etc quickly discharge through the circuit they are part of.

You will be perfectly safe so long as its not plugged in, simple as that, just dive right in and touch whatever you feel like!

But if you dont feel confident enough or you dont feel safe then dont mess around with mains power.
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Re: Apple ][e Fireworks Display

Postby SpidersWeb on Tue Jan 20, 2015 5:44 pm

I'm all for giving it ago, but I do think a healthy respect for a CRT is a good thing.
Most devices will have a bleed resistor - but just in case it fails I just check with a meter first, and avoid the HV/EHT (if I need to go near it, one hand behind my back)
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Re: Apple ][e Fireworks Display

Postby acsi on Tue Jan 20, 2015 6:38 pm

I aint been shocked yet but appearantly DC is the most dangerous.


Yep AC will put your heart out of rhythm which can cause it to stop whereas DC just seizes your heart.

As for the caps the bigger the more charge they tend to gold. They could easily cause a nasty burn as you would normally short them across a finger, but if your unlucky (especially if you still have the plug in :oops: you can get a discharge across your heart (back to ground or hand to hand) which can damage your heart.

Just a note that if you do get a shock to go and get an ECG as your heart can go out of sinus rhythm and kill you later down the track.
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Re: Apple ][e Fireworks Display

Postby Radar on Fri Jan 23, 2015 1:36 pm

I got some spare caps here from when I've fixed my own Apple II monitors in the past if you want to swing around (sure you are still close by) with the screen I can swap them if they are same?
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Re: Apple ][e Fireworks Display

Postby Radar on Fri Jan 23, 2015 1:36 pm

I got some spare caps here from when I've fixed my own Apple II monitors in the past if you want to swing around (sure you are still close by) with the screen I can swap them if they are same?
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Re: Apple ][e Fireworks Display

Postby Gurner on Sat Jan 24, 2015 1:48 pm

Radar wrote:I got some spare caps here from when I've fixed my own Apple II monitors in the past if you want to swing around (sure you are still close by) with the screen I can swap them if they are same?


Hi Radar,

PM sent.
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