Fluke 97 LED backlight conversion

[mlefe]

I've recently acquired a Fluke 97 from eBay and, like many of you noticed mine also had a very dim backlight.

I've decided to do something about it and, after reading what joeqsmith did to his (thanks for the info!), I ordered the same EL panel he got.

After installing it, I wasn't convinced on the result so I took a different route: I reused a broken LCD monitor panel from a notebook (both the different sheets and smd LEDs).

I've tried several options to run the LEDs (several configurations in parallel and series with different rails within the scope)… but the one that finally did the trick was:
* Cut a suitable sized of the LCD monitor to fit where the EL panel was and retrieve the full LED strip from it
* Separate 10 LEDs from the strip, cut them and put them back together in series on top of a piece of Kapton tape
* Take the backlight signal and use a 2N3906 to enable a TIP122 to provide power from the -30V rail to the LEDs
* Try to don't make a complete mess with the wires, hot glue and tape inside the scope 

In the end, I'm very happy with the results, although I'm sorry for the quality of the pictures and the wires and mess, I didn't have the confidence that it would work.. 

The image with the backlight looks a bit overexposed in the bottom in the picture, but it's not noticeable in real life and looks good and bright.

I hope this gives you some alternative ideas

[InnocentBystander]

Hi there, thank you very much for this idea! 
It's been a while since you posted it, and when one these Fluke97 scopes crossed my way recently, no suitable EL foils could be found anymore; and if there were, the space underneath the display never was enough to fit in a contact ... soldering on these plastic sheets is impossible, of course.

Question: Would you be so kind as to help me with some details where you connected the LED strip to? In your drawing you connect the switch circuitry between -8.17V and GND, in your text you write about a -30V rail. Can you tell me where to solder them to?