I'm sitting here typing, watching IDHD (I know...slow day. Slow life, actually) I have a Sanyo HT28745, the mystery set that WalMart sold only a short while in mid-2005. I paid $470 for mine, which was the demo, so it had been on for weeks. What I remember most about that purchase is my back being out for three weeks after I got it up to my condo.
I have had the "green" problem, and the "floating sync bars" problems. All were cured by removing the main board and carefully resoldering all pins to the video board socket. It seems that using a lot of connecting cables on the back flexes the main board, causing bad joints to open.
My set has never failed. It has survived lightning, 100% humidity for a weekend after Matthew hit last October, and it still meets specs.
To this day, it produces the most natural color picture I have ever seen. I should point out that I was in TV engineering for 40+ years, and designed and built over 15 complete TV stations. So, I have seen a few good color pictures...and I know what to look for.
In 2008, I found service instructions for a similar set, and decided to touch up the factory rom settings. Mine, like most, had a slight tilt. I did not touch the yoke, which is the only way to correct the tilt. I would rather keep the perfect convergence. Every other size and linearity and registration setting was near-perfect, and now they are.
The horizontal linearity on any CRT with a deflection angle of over 90 degrees is going to suffer.
Think about a car headlight trying to illuminate a sign on the opposite side of a freeway and you'll get what I mean. I did achieve the necessary reduction of factory overscan needed to read sports graphics. I also got the gamma and grayscale exactly as it should be, based on the characteristics of P22 phosphor. This is VERY important when watching classic movies on TCM or wherever.
I was again fortunate. Like the older sets discussed here, the 28745 has a velocity modulator. It works. The later sets, especially the HT30746 omitted this feature. It makes a HUGE difference in perceived clarity, especially in low lights, because it pre-compensates for discrepancies in the CRT itself. The later sets merely had hi-frequency boost (sharpness) which helps, but does nothing but add noise to low lights...and moire to tweed.
Except for complete cleaning every three years, my set has not been touched since Spring of 2008. That's pushing 50,000 hours of use now. The tube tracking and warmup are as-new. It may die tomorrow, but so might I. At less than one cent an hour, I am well-satisfied.
Of course, "progress" always rears its ridiculous head. My Comcast box and my WDLive both have YPrPb outputs, but that is bound to change. Fortunately, friends and my present wife took my advice and bought the Sanyo. Unfortunately, they wanted HDMI and got the 30746. One failed and sat for 8 years. My (now) wife's has sat in her Tennessee bedroom since 2010, a year before we were married. The friend recently loaded his and brought it 250 miles to me. It was an easy fix: the combo gun driver chip and a few associated diodes and transistors on the CRT board. (Another chopdown: the 28745 and older sets used three gun drivers with greater output and perfect reliability.)
When researching the various models, looking for an old digital tuner with HDMI that might work in the 28745, I was amazed at how many chassis re-designs these sets endured in the 3 years they were made. The first two years were improvements. The last was cheapening. The 30746 has HDMI, but it lacks the VM and preset colorimetry functions of the 28745. By finding and changing a few rom settings in the various sharpness/contour circuits, I have it looking nearly as good as the 28745...
With two notable exceptions. The 28745 used HV limiting and beam current sensing to prevent the CRT damage mentioned so many times above. The 30746 uses the HV limiting, but also clipping in the single-chip CRT driver board. No CRT I have seen has any sign of the damage, but the combination of changes on the 30746 makes the picture slightly less-than-perfect. It also tilts a bit more. But, so do I these days.
When I go to friends and relatives houses, I honestly wonder how they tolerate the solid state screens. (As if they had a choice. The last CRT plant in the world rolled to a stop in 2011.) I've seen more-accurate colorimetry on Polaroid film. I'm always glad to get home to my Sanyo.
God-willing, it will outlast me.
If anyone has a 28745 with the HDMI input, I'd appreciate you letting me know before you trash it.