I acquired a spare climate control from a 1999 LS400 to have a look inside without the need to disrupt mine..

My incandescent backlighting is not as bright or uniform as the replacement Radio LCD display I installed in the OEM Pioneer radio, so determined to investigate further.

The 10 backlight bulbs - 5 with white twist socket base and 5 with black (suggesting they are different) all have a high grade green silcone rubber color lamp filter boot

The color filter is removable to assess bulb condition...All bulb glass envelopes interiors were slightly tarnished ... not bad, but contributing to observed inconsistent illumination. The plastic white twist sockets were slightly burnt.

So will order replacements for mine from Lexus to avoid fitment and quality issues of aftermarket "stuff".

The other thing I observed on the backside of the climate control face circuit board was tarnish and crust at through hole solder points...in some location there was creepage of this crust across circuit board traces...image below.

Not sure if mine will exhibit this but am sharing what I found here..thermal cycling perhaps.

This could be corrected by cleaning (if not sure how to do then find a geek) and hitting each through hole solder joimt with a soldering iron to freshen it up.

The seperate logic board contains 11 United Chemicon KME series 35V 47 microfarad capacitors...

These are superceded by the KMG series which I have attached a datasheet PDf and images of labels of 50V and 60V capacitors purchased from Digi-Key..
The new 35V would be too wispy..

Capacitor technology has improved such that for a similar case size you now get 63V (higher voltage is a good thing)

Back of climate control head circuit board...crusty at all through hole solder joints with crust migration across traces in some places. Worthwhile to inspect.
Bulb and socket assembly sold as a unit...
Slightly tarnished bulb...
you can buy raw incandescent bulbs to relamp but not worth the effort.. The color filter cap is reusable but unsure at this juncture whether it is included with the lamp/socket assembly or not..
The other thing is I noticed all of thes cap filters were not fully set on the bulb(air pocket at end) This will interrupt illumination.
Lamp color filter is taller than bulb so you get an air pocket at the end and the color filter. This can become more of a barrier to light rather than a color diffuser. The remedy would be to either fold to a lip at the base or IF you have really good eyesight a very sharp tool and a steady hand to trim the colr filter to proper length.
Wet the bulb or inside of filter for ease of installation.
New 47 microfarad 63V capacitor next to existing 35V...very similar case size.
DIGIKEY P.N. for 47 microfarad 63V
....47 microfarad 50V is slightly smaller


www.google.com/url?sa=t&source=web&rct=j&url=http://datasheet.octopart.com/KMG16VB471M8X11LL-United-Chemi-Con-datasheet-21267410.pdf&ved=0ahUKEwjkp9GB29fTAhVo2oMKHbt1AkcQFgg9MAc&usg=AFQjCNESXj7g6nt09nWs0YSP80t_XXSiQg