Monitor Wei-ya / Se-Cai '21, the brightness does not hold!

[marcelosofth]

The brightness does not hold! 

Hello friends, I bought 2 monitors for my Arcades, but I'm not getting a proper adjustment, the geometry, colors and image are excellent, but I do not know what happens, because whenever you have images with more brightness, that is with more light, automatically the monitor drops the brightness and leaves an opaque and dull image, after the image of brightness exits like for example of the gameplay of a game and enters the intro, the monitor recovers all the brightness of the introduction, therefore it has many black parts in the screen , but upon returning in the gameplay the brightness again goes away. 

Ps. I've done all kinds of adjustments in the 3 Yoke trimpots, adjust the Flyback Screen, and even in the Trimpot B + of the voltage, the image is beautiful and adjusted, but just enter a bright image of a gameplay and the brightness falls again. 

Monitor Se-Cai / Wei-Ya '21 using a PC 

I made a video to help better understand the problem:


I will be eternally grateful for anyone who has a light of this nightmare who insists on following me ok. 

[grantspain]

that is because the chassis is extremely bad quality and is not built to do what you are doing
wei ya are the better of the chassis that the Chinese copy/ build and even they are absolute rubbish compared to something like a nanao

[lilshawn]

your video makes it very hard to tell, your camera is not using a fixed brightness. Ideally you want to set it to record 60FPS and fix the brightness so that the camera does not compensate for the varying light levels. BUT this is not a camera post...

I've actually had this question before and you issue seems similar.  It sounds counterintuitive, but... I'd say your screen brightness and contrast is TOO high... maybe causing mask distortion.

otherwise, since this looks like a new chassis, i'd say the B+ circuit is operating properly... but having messed with it's setting, you better hook up a voltmeter and verify it's where it should be. Irrespective of the image quality, running a chassis with improper B+ voltage (high or low) is hard on components. The service manual for your chassis will outline specifically what must be displayed when checking B+ (usually crosshatch pattern)

Check out "EIZO monitor test" for a good program for windows to test your monitor with.

Don't forget, this is CRT monitor with a brightness level far lower than modern LCD and Plasma displays. Your vision has been sullied by modern super bright displays. The CRT is not designed to be a super bright display. Many manufactures run them really hard and you end up with burn in within a year or 2.

A good rule to set up the monitor screen and brightness is to turn the brightness and contrast knobs to 1/2 position and display a 100% black screen... adjust the flyback "screen" control up until you can see the screen start to turn a little bit gray...then back it off until it's black again. this is usually sufficient and a good place to hang with your brightness and contrast adjustments. you don't want them cranked up all the way.

[marcelosofth]

For the 3 Cutoff trimpots how should I leave them?

I saw someone else reporting the same problem as mine: 

But the biggest problem on the WeiYa was considerable "softness", I've seen some call it "blooming". No matter the position of the cutoff/drives/brightness/screen controls, you either had considerable blooming/softness (without being sharp). If you turned them down enough it reduced the blooming and got a bit sharper (could see more of the dots making the image) but then contrast/brightness went away. You could barely make out many graphics that used darker tints of colors.

The WeiYa also seem to "pulse" based upon overall brightness sent to the screen. For example, in Galaga's boot sequence, a bunch of characters on a black screen appear, and look like the correct color. Then the screen reverses to a white backrground and instantly the WeiYa chassis seems to cut down the power output and tint the screen purpleish instead of white, and a lot dimmer. When that part of the boot is done and the cross hatch appears, it again is white. This does not happen on the 8liners chassis.

[grantspain]

if you look at the design of that chassis it is so basic that it could never produce a decent stable picture, I doubt there is an abl circuit on it