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Testing any Monitor Without PC

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New Member
Hello there,

Wondering if anyone got a Circuit for Testing any Monitor Without PC .
Something Like a Screen Saver Circuit to be injected to any Monitor .
Something Like Color Bar Generator Circuit for Testing any Monitor .

Thanks in Advance .


Active Member
I feel that such a unit could easily be made.
Maybe a few square waves on the RGB inputs
would give a sort of tartan pattern.

A lot of monitors have a sort of 'Standby Mode'
which they go into as soon as the computer is
switched off.
I dont know how this is arranged,
but it would have to be addressed.

Regards, John :)


signals required are RGB and either composite sync or Vand H sync pulses......absence of sync will cause the monitor to "go to sleep"


Active Member
Hi Chippie,

It took me a while to figure out what 'Vand H' synch
pulses were.

Vertical and Horizontal synch pulses!

John :)


Active Member
This circuit not simply made for "any" monitor testing, because the H-frequency and V-freq. (sync pulses) depend from resolution. (H 31.5....100kHz, V 50...120Hz) If You thinking about test equipment,need cca.50...70 variations with frequencies.(most of monitor failures appear only in one or two resolution...)


Active Member
Some of the new monitors come with self test facility. When not connected to PC, they fill up the screen with up R, G & B colors alternately. Don't know if all monitors have this facility but mine does.

1997 GA16DE

New Member
yea, just about every new moniter has a self test that comes up when there is no signal (unless on sleep mode).

If you wanted to get any kind of image on the screen, you would at least need a video card, and making the video card work w/o a PC is beyond me.
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