Newbie schematic reader - please help

[survivalbloke]

I've attached a schematic of the board I'm looking at. The LCD backlight is not working and I'm trying to determine how that circuit is protected. What is the easiest means of finding this circuit on any given schematic?

Thanks!

[mon2]

Re: Newbie schematic reader - please help

Search for the keywords like 'lcd' or 'backlight'. Important to try all permutations to find the portion of the schematic that is relevant to the work. For example there will be a backlight for the keyboard, etc. Lcd is a good one.

[Sephir0th]

Re: Newbie schematic reader - please help

Page 55. Main reason for missing backlight are issues with DCBATOUT_LCD, BLON_OUT_C and LCD_BRIGHTNESS. Check these lines for proper voltages with internal display attached.

[survivalbloke]

Re: Newbie schematic reader - please help

Search for the keywords like 'lcd' or 'backlight'. Important to try all permutations to find the portion of the schematic that is relevant to the work. For example there will be a backlight for the keyboard, etc. Lcd is a good one.

Thank you!

[survivalbloke]

Re: Newbie schematic reader - please help

Page 55. Main reason for missing backlight are issues with DCBATOUT_LCD, BLON_OUT_C and LCD_BRIGHTNESS. Check these lines for proper voltages with internal display attached.

Got it, and thank you. Guess I'm going to need a boardview for this. I'll see if I can scare up one of those and continue my checking.

[Sephir0th]

Re: Newbie schematic reader - please help

Got it, and thank you. Guess I'm going to need a boardview for this. I'll see if I can scare up one of those and continue my checking.

We might be able to lead you if you share clear pictures of your board

[survivalbloke]

Re: Newbie schematic reader - please help

We might be able to lead you if you share clear pictures of your board

I'll take you up on that. Thanks!

[Sephir0th]

Re: Newbie schematic reader - please help

LCD1, Pin 1 is most right in this picture. You can measure DCBATOUT_LCD without display connected, but for the other signals you might want to find a better test point with multimeter, while the display is connected.