older 2970 display troubles

[bioman]

i just bout an older 2970 <orange display with battery> and am having a problem with the display

when you first turn it on it displays fine but after a minute or so the numbers and all fade away

the orange is still lit up but the screen goes blank

i just replaced the battery in it but it was doing it before i pulled any covers off

i only replaced the battery because it would reset itself back to stock everytime id turn it off

i metered the old battery and it had a voltage of .412 volts


thanx in advance

scott

 

[nomadradio]

The oldest version of the radio (memory battery) has a separate pc board for the display, one for the CPU, and another small one with the two rows of momentary push switches.

On the LCD display circuit board, just beneath the LCD is a tiny surface-mount trimpot. This is the contrast, or "Viewing angle" adjustment for the LCD. Since my Turbo is on a shelf above my eye level, it's adjusted so I can see it from a low angle. Look at it from above, as if it were on a desktop, and it looks pretty distorted.

This trimpot will make the display go blank if it becomes intermittent or cuts out completely. Often a slight (and VERY gentle) turn of the slot will bring it back.

Always suspect the moving parts first, when they are on the list of possible culprits.

73