Kerry Wong writes:
If you take a look at the picture below, you may recognize immediately that it is a picture of an HP 8642B synthesized signal generator. But if you take a closer look, you probably will notice something different if you have ever used an HP 8642B before.
The original HP 8642 series used two miniature incandescent light bulbs for the instrument LCD backlight and the backlight has an orangish color to it. Unfortunately these light bulbs do not last that long (a few hundred hours) and if you got a used HP 8642 chances are that the backlight no longer works. This is exactly what happened to my HP 8642B. Unfortunately, without the backlight the instrument display is pretty difficult to read. So I decided to open it up and change the backlights.
Awesome! I am going to give this a shot with my 8642!
Very nice work, thanks for the suggestion. I really do like my 8642B’s, wish that they were 8640’s though.