ThanksYou could remove the cluster and replace the tiny incandescent bulbs with LED replacements.
I had a couple of bulbs out on the overhead console and instrument cluster on the 08 Toyota Sienna. Replaced all the bulbs with LED's from Superbrightleds.com. Not sure what model and year vehicle you have but Toyota wanted ~$7 per bulb and I paid about $2 each for the LED replacements. These are quite a bit brighter as well.
Thanks for the information .There is nothing wrong with your cluster. I mean there is, but it's not broken. It is simply how Toyota made it.
For whatever dumb reason Toyota shut off the backlighting of the gauges from I believe it was model years 2014-2017. Only way to get them to back light is to turn on the headlights or at least the driving marker lights on those year models. Drove me crazy when I had a 17 Tundra. Did not matter what trim either.
I had a platinum that I personally drove and had a SR5 long bed for the shop, both were the same, could not see the gauges without turning on the headlights. I later had a 2020 Platinum and also still have that 2017 and 2 more, 2021 SR5s long bed in my business. I complained to Toyota dealer about this for years on those older models, always the same answer, nothing they could do. Toyota must have heard the complaints, since they did fix it on, I believe the 2018-2021 models. Our 2020 and 2021s backlight the gages all the time like they should be.
The dial on the left panel side of the steering column adjust the angle of the headlights Up and down.I tried head lights on and rheostat adjustment to the left of steering and with lights on it looked like the cluster lights changed an estimated 1/2 candle power .
ThanksHere is couple videos.
i am pretty sure your 2016 is like this video showing how to tips on a 2014.
See this video at 3:35 time mark he shows the dial to turn up the back lighting when the lights are on.
The newer models 18-21 are back lit all the time and use this method to adjust the brightness.