How to get a brighter contrast on a humminbird 898

With this type of issue.. its the transducer mounting ...99% of the time!!

If your problem is that sunlight makes it difficult to see what is displayed on the LCD screen, you can make the LCD display brighter by going through the menus to the option to adjust the LCD brightness. Move it to the brightest setting and see if that makes enough difference. You can also buy an LCD hood to shield it from the sun. Hope this helps!

WITH THE REMOTE...CLICK ON THE MENU...GO TO VIDEO SECTION...THERE SHOULD BE A BRIGHTNESS...CONTRAST....THAT SHOULD HELP THE PICTURE TO BECOME BRIGHTER.

The NS25 uses a much different god receiver than what is available now and will not work with your 898. What you will require is a AS GRP receiver. https://www.humminbird.com/Products/AS-GRP/

Source: mikesreelrepair.com & Humminbird.com

take it off auto and set contrast to your likings

Please check the light settings and change from high sensitivity to even a manal mode or a bright sunlight setting.
It is possible that the incident light is too powerful and so changes the auto light sensor to give a correction to the CCD so as to make it less brighter.
You can also try and use filters that can reduce the glare but give a better picture contrast.
If not use the manual mode, correct the speed and aperture.

How to get a brighter image on hummingbird LCR4 ID

Over time some nozzles burn out on your printhead. Adjusting the contrast can make the lines less visible, but the best repair for quality photos is to replace the printhead.
QY6-0061-010 around $50.00

Contrast ratio is the ratio between black and white. So low contrast ratio (5000:1) means you can;t see the screen so well in a bright room (where there's a lot of sunlight) A higher contrast ratio (20000:1) means the screen is brighter so easier to see in bright rooms.

Pixel pitch refers to the distance between pixels. The lower the pixel pitch, the sharper the image

Try tapping the power key while the unit is on.  This may activate a control for contrast and brightness.  Otherwise it's in the settings screen.  Try looking at the screen in bright sunlight it may be make the screen visible enought to see the settings.