I havce recently aqquired four of these monitors, all of them have the same systems.

The color bleed or strechs across the screen. Move the mouse on the left side of the screen and a long line strechs across to the right side as the same horizontal place where the mouse is on the left. Its like that with all bright colors on all four monitors. All four have been used a fair amount. Everything else works normally.

No signs of bad caps in the first one I looked at, no heat marks etc etc. I heard that the power transistors can go bad in this model, after translating a german web page to english.

Anyone experienced with these or have a schematic? I have some pics of it.

Thanks,

-Steve

look for small value caps in the video O/P section, usally on the RGB Drive board, particully any small value bi-polar caps. don't bother measureing them, they will measure OK, just change them.

No one is experienced with or knows where to get schematics for this monitor are they?

-Steve

Sadly the symtoms you discribe are the symtoms of an wornout picture tube, try and adjust the screen pot at the FBT, and turn the internal color controls up and down, if you can't stop the color running, then I would say the picture tube is worn out.
Also, check that the heater voltage is 6.3v, measure this right at the pins of the CRT. Its common that Heater voltage drops due to old caps, and it will also give the same symtoms.
so..
Step 1. measure heater Voltage.
Step 2. turn up screen voltage
step 3. adjust internal color controls

if you take all 3 steps and the color is still running then change the picture tube.

Appreciated your help,

Internal color controls and screen brightness affect nothing. I will work on checking the heater voltage.

What causes these tubes to wear out, or what is missing when they wear out, why would it just cause horizontal color bleed?

Just curious on the theory behind it.

Heres a pic,



Thanks again,

-Steve

The cathode in the tube wear out and gets covered with exceses particals.

I was reading today that you can tell if the vacuum is bad on the tube by the color of the getter on the inside of the tube. Silver is normal, white or red is bad.

Hard to find a definition of exactly where the getter is. But, if I look across the neck of the CRT in the glassed in part, on an angle I see silver. I would assume this means the vacuum in still intact.

That and I can adjust the CRT voltage and the sceen will still go quite bright. Is it possbile for the vacuum to still be good but the CRT be bad?

-Steve

Hi as for the getter colour changing with the vacuum of the CRT I can not say.

The picture you see can be caused by a tired CRT equally it can be caused by low value caps on the video PCB's or a leaky diode in the clamp circuit or a leaky transistor/IC in the video path.

You will find schematics for these hard to find as Eizo UK charge £80 for a CD with a single model manual on it.

Rich

Thanks I will check into it, maybe theres some hope

-Steve