Please help! for repairing of Yokogawa GD402G/M1.

[RaymondRosas]

Hello Everyone to define the model of the LCD screen of Yokogawa
I'll already check all components using the fados9f1 tester and ESR capacitor
meter. I found out all capacitors of the power supply are failing in
ESR. I changed everything but he is still like that. There is a display,
but you still need to use a flashlight on the screen. I suspect that the
The LCD screen needs to be replaced, but I can't find the model of the LCD screen.

[RaymondRosas]

The lcd does not have backlight, Behind the lcd there are two programmable ic PD7225 lcd, programmable controller,do you think that is the problem.

Data Sheet of PD7225

https://pdf1.alldatasheet.com/datasheet-pdf/view/7013/NEC/UPD7225.html

[jchw4]

Comparing


to https://www.yokogawa.com/us/solutions/products-and-services/measurement/analyzers/gas-analyzers/gas-density-hydrogen-purity-analyzer/gd402-analyzer/ :

suggests that most of the display area is free of display segments and should be transparent (i.e. white background visible). Which means that the polarizer film is dead. Please also see the discoloration wround the edges.

You can buy polarizing film and replace it. See

for example. I would not personally recommend the exact method they use in this video. In my experience adding a drop of acetone between the polarizer and the glass helps a lot. Way less stress to the glass. But otherwise the video is correct.

It is important that you buy a transflective polarizer. Please also read about different polarizer types on the Web before buying new film and trying to remove the old one.

[RaymondRosas]

Thank you so much..sir....