I have had cold weather problems with my G430W. When first going through it’s start up sequence, it would give me a washout in half the screen only on one of the progressive screens, and interestingly, not the first. Then after a few seconds it would improve, then normal operation for the rest of the flight. After about a year of similar cold weather symptoms, the same screen showed washout, but this time in the superior half, not the other half, then normal operation. The final straw was while flying, the nav screen became washed out during one flight. I was postulating that it seemed like a software issue, although it could have been impending screen failure. My avionics tech didn’t know but sent it to Garmin for repair. They replaced some sluggish buttons, did a complete software/firmware upgrade but did not find anything wrong with the screen. They charge a common rate of about $1850 no matter what they replace. It works quite normally since, and have been through one winter.
While considering my options beforehand given the expensive Garmin flat rate, and the cost of swap out with the IFD440, which is not cheap, I think I am way ahead doing the repair if I get at least several more years out of it even after it should become orphaned by Garmin.YMMV
