My Dell P922 monitor is too bright. Even at minimum brightness setting, it still shows retrace lines. Otherwise works fine. Anyone know of a source of technicial info on this monitor? I think its made by Sony.
Thanks, Chuck
My Dell P922 monitor is too bright. Even at minimum brightness setting, it still shows retrace lines. Otherwise works fine. Anyone know of a source of technicial info on this monitor? I think its made by Sony.
Thanks, Chuck
This is a common problem (with similar monitors as well). IIRC, you can rebias this with a change to a resistor (though that isn't the "right" solution)
t
It's what happens when the SCREEN control (one of the pins on every CRT is a high-ish voltage electrode called the screen) is out of adjustment (or broken entirely).
Adjust the black knob labeled 'screen'; if that doesn't work, the gain-setting (fixed) resistors attached to it have failed, must be replaced.
Here is a link that has much on your problem.
Somewhere in there is a fix via the resistor change. If you cannot find it, post that fact and I will search through my notes on the monitor fix. The Dell monitor is made by Sony if I recall correctly.
Yes, it's a Sony monitor. The screen adjustment is done via software. This thread covers the options.
PlainBill
Well, it puts the proper voltage on the screen grid of the CRT; I'm not sure what's not "right" about that.
BTW, it's probably a good idea either to use high voltage resistors or to make up the value you need out of two or three smaller (but equal value) resistors in series; there's not much current there, but the voltage across those resistors makes a longer arc path a good idea.
That said, this fix has restored at least three of these monitors to useful life. I got 'em free because the brightness control didn't work
8^}.Isaac
I found these notes from some old posts, don't know who wrote them but they worked for me:
having repaired over 500 Dell P1110
Most of the problems I have seen are for Excessively bright picture.
R459 is the best to Mod and Have found that 5.6M ohms to 7.5M ohms to be the
repair range depending on how bright the picture has become. The lower the
Value of R459 the darker the picture will become. I have noticed that when a
lower value is needed often the bightness adjustment will also shift the
picture color. Darker settings will shift to blue and brighter settings will
shift to red. I have not found a way to compensate or repair this problem.
also:
This is a common problem with these monitors and there are many posts about
it in this forum. The best solution is to change a resistor - R459 on the
tube base board to a lower value. It should be 10meg ohms but changing it to
a 6.8M ohm should bring the brightness level back to a normal level. Doing
the colour restore after changing the resistor should bring it back unless
the CRT is faulty.
-- They can have my command prompt when they pry it from my cold dead fingers.
There are three problems with this approach, and one advantage.
First of all, changing resistors because you can't do the adjustment is a kludge. Second, it gives only an approximate setting. Third, the CRT characteristics will continue to change, and you will once again have to change the resistor.
The advantage - it's easier (and cheaper) than building a rs232 to ttl adapter. Of course, a 74C914 IC will do an excellent job and costs about $5.00 (including shipping) from DigiKey.
PlainBill
Yeah, sometimes you have to work with what you have available. Of course, an adapter to allow doing the adjustment properly can be built for about $10 (less if you have a well stocked junk drawer). And you don't even have to open up the monitor.
PlainBill
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