KDS XF-7b Monitor: Worth opening and refocusing?

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KDS XF-7b Monitor: Worth opening and refocusing?

Postby TheAbandonwareGuy » 2017-3-16 @ 23:21

I have a KDS XF-7b monitor that I just now have gotten around to testing. Supposedly its a 160HZ Flatpanel CRT. At every resolution its too blurry to read anything at all, even the start menu is a blur. I'm guessing this means it's fallen out of alignment. So this leaves me 3 questions:

Is it worth the risk of opening it up, hoping it has alightment knobs on the flyback, and then risking electrocution adjusting them? I know what I'm doing with electronics but I've never messed with THAT much voltage before. I'm not even sure this will be a better monitor than my Gateway EV700. Its 7 years newer but still I'm not sure the brightness/black levels will be up to par.

and what happens if I do mess up (and the voltage doesnt kill me)? Am i going to lose a hand from having it fried by high voltage or someshit?

and most importantly, what is proper procedure for retuning a CRT? Ill also readjust the brightness if the knobs happens to exist to do so.
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Re: KDS XF-7b Monitor: Worth opening and refocusing?

Postby Imperious » 2017-3-20 @ 07:06

You would really have to be quite careless to electrocute Yourself doing this, like touching metal parts of the monitor whilst turned on.
CRT monitors/tvs usually have around 25000 volts at very low current.
Use a plastic tool for adjusting and don't touch anything else whilst it's on. the tube will hold voltage whilst it's off as well.

Most decent monitors will have 2 focus pots and a screen (brightness) pot. The 2 focus pots are horizontal and vertical so make sure
you have a decent pattern on the screen when adjusting.
Don't go too far with the brightness pot or You will get retrace lines on the display.

Computer monitors are normally ok, but many tv's needed to be supported with the back removed.

Do it at Your own risk obviously. I used to do this all the time when repairing tvs.
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Re: KDS XF-7b Monitor: Worth opening and refocusing?

Postby kaputnik » 2017-3-20 @ 11:04

Imperious wrote:You would really have to be quite careless to electrocute Yourself doing this, like touching metal parts of the monitor whilst turned on.
CRT monitors/tvs usually have around 25000 volts at very low current.
Use a plastic tool for adjusting and don't touch anything else whilst it's on. the tube will hold voltage whilst it's off as well.

Most decent monitors will have 2 focus pots and a screen (brightness) pot. The 2 focus pots are horizontal and vertical so make sure
you have a decent pattern on the screen when adjusting.
Don't go too far with the brightness pot or You will get retrace lines on the display.

Computer monitors are normally ok, but many tv's needed to be supported with the back removed.

Do it at Your own risk obviously. I used to do this all the time when repairing tvs.


As above. Always regard the CRT's innards as energized, no matter if it's plugged in or not. On that note, there are plenty of high voltage caps with high enough capacitance to be dangerous in CRT:s, be extra careful with those too.

Would definitely use long sleeved rubber gloves when working with a live CRT. Exactly how high voltage you should expect is impossible to say, mostly depends on tube size, but you should be ok with gloves rated for 10 kV. I'd guess only large screen TV:s go above that.
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