HP4396B dim display

[chilternview]

I have acquired a HP 4396B network/spectrum analyser which is in excellent condition with useful options (010,1D5). The only problem I have is that the LCD display is a little dim - it's readable but not in bright light.

Is this a known issue, or is it likely that the backlight has lost brightness with age? And is there a way of fixing it?

[chilternview]

Just in case anyone has the same issue in future: the display is a Sharp LQ9D340H. They are available on eBay for around $150 new, so I've ordered one as a replacement.

Getting to them is easy: there are a number of countersunk head screws that secure the front panel to the main frame. To remove the ones at the top you need to remove the trim strip. After undoing them all, the front panel can be gently pulled forward until it clears the inputs. The two screws that secure the display cover can then be removed, and the cover levered up and removed. Then undo the 4 screws that secure the LCD display. It has a 2 pin connector for the backlight and another connector for the drive signals - remove both and then fit to the new LCD and re-assemble.

[R-1125F]

It is probably the CCFL backlight going bad. Best to replace with LEDs.

[chilternview]

I agree LEDs would be a better long term solution, but that needs a suitable supply for them including support for display on/off and intensity before it is a complete replacement.