TV failure - terminal?

[meow2222]

Worth putting on the wiki, but I've no idea what to call it or what else to add with it. Any suggestions?

NT

[The Natural Philosopher]

Interestingly enough, I googled 'sony LCD TV 32 inch and SONY LCD TV 32=20 inch and also plasma.

The results were that a sony CRT is about 100-130W, and so was the LCD=20 TV. Light is light and phosphors ain't much different than whatever they =

use for backlighting LCDS.,

Plasma are twice as bad tho roughly - 230-260W IIRC.

standby on the LCD was 0.7W, the CRT was 0.3W....

Oh here's a good site.

NT

[The Natural Philosopher]

Juyst linkl to that page I posted, which shows that LCD are no better=20 than CRT Tvs and plamsamas are trwice as badf.

Heading 'ecobollox'

Put in the usual warnings about domestic windmills, domestic solar=20 panels, CFls' mobile home chargers etc etc.

And a short paragraph that says

'saving the planet simply means using less. Of everything. And building=20 nuclear power stations.And wearing jumpers in winter. Nothing else works.= '

[meow2222]

'Emission' means the ability of the picture tube gun to emit electrons. When that declines, the picture gets dimmer and dimmer, and the colours go wrong. Some sets are more prone to it than others.

User fixable? no chance. But its doable with a bit of basic electronic skill, the sort of thing many DIYers could do - and many couldnt.

[Fredxx]

Even with knowledge of electronics I rarely feel it's worth messing around with an old tube which is getting dim. That does assume it is the tube.

Generally increasing the heater power as the wiki says can give a good result and there's nothing to lose. At one time you could get special heater transformers which gave selectable boost. In the days of wodden cabinets they were easy to fix in! Sometimes a boost was as easy as shorting out a resistor on the CRT PCB.

There are also techniques of bumping a tube by passing a large momentary voltage between all the grids and cathode, the idea was to damage the cathode to present new clean unpoisoned matierial. I didn't think it was very reliable though and provides a quick route to a scrap tube!

The cathode response is very non-linear and increasing the drive can create less than natural colours. Generally skin tones and brown hair were the two more important colours to get right if there were an issues!

[Arfa Daily]

Interestingly enough, I googled 'sony LCD TV 32 inch and SONY LCD TV 32 inch and also plasma.

The results were that a sony CRT is about 100-130W, and so was the LCD TV. Light is light and phosphors ain't much different than whatever they use for backlighting LCDS.,

Plasma are twice as bad tho roughly - 230-260W IIRC.

standby on the LCD was 0.7W, the CRT was 0.3W....

Oh here's a good site.

NT

Most modern CRT sets had got their power consumption down to below 100 watts. LCD TV display panels are backlit by a series of thin high intensity flourescent tubes. The high voltage for these is produced by a multichannel inverter board, which takes a 24v rail from the set's power supply unit, and pulls 4+ amps, so that's 100w input just to run the backlights. The signal and system control processors on LCD TV mother boards run so hot you can't touch them. The 5v and 3.3v rails are each providing an amp or so in some sets, so that's another 9 watts. I have an LCD set on my kitchen wall, and you can feel the heat pouring off the front of it, as you walk past. Modern TV technology certainly hasn't done anything to improve the running power. As you say, plasmas are worse still. Funny how the green mist ecobollox brigade haven't picked up on this fact, yet cry continuously about the standby power consumption, which actually *is* much improved over older linear and switching supplies ...

Just as a little aside, I saw a write up on a new LED light bulb from America. Its makers are hailing it as "The best light bulb in the world". I should bloody well think it is at $119 a pop !

[meow2222]

These approaches are right at the end of their usefulness now, shame the wiki didnt exist years ago.

NT

[Dave Plowman (News)]

Difference is the LCD power consumption is pretty constant due to the backlight - a CRT varies with picture content.

[Dave Plowman (News)]

The correct way to line up a CRT is to get the grey scale correct. Colour response will then be as good as the phosphors can manage. But quite a few are incapable of giving accurate flesh tones due to the phosphors used.

[meow2222]

The point is that on a tube that has been brought back from low emission its often impossible to get the grey scale correct. Gamma varies from one gun to the other.

Fwiw I once had a set that gave a very odd set of colour blocks, due apparently to odd phosphor colours, but it looked ok in general use, ie skin tones looked ok.

NT

[Dave Plowman (News)]

Scrap it then. You'll get a working CRT TV for nothing easily. Some might pay you to collect.

One which gave peculiar colours in the blacks or foregrounds would be totally unacceptable to me - even if the flesh tones were *sometimes* right.

[Kostas Kavoussanakis]

switch-on from a (probably) different fault.

Kostas

[meow2222]

I think we've got wires somewhat crossed on this. It doesnt matter

NT

[whisky-dave]

First you'd need to know the power consumption of the 2 sets you want to compare. The label on the set indicates the max consumption, and figures can be calculated from those. If you want more precision, you'd hook the 2 upto an energy consumption meter (killawatt etc) and measure their consumption exactly.

Example:

Say a TV eats 100w and you watch it for 2 hr per day. (I'm picking easy figures) Consumption = 0.1kW x 2hrs = 0.2kWh per day = 73kWh / yr Price of electricity = 12p/kWh So annual energy cost = 73 x 12p = £8.76 / yr If typical life expectancy of appliance = 8 yrs, thats £70 per life of the product.

Now compare an LCD with 70w consumption cost/yr = £6.13/yr = £49/ 8yrs Difference = 70-49 = £21

Difference in purchase price is greater, so the LCD never pays its savings back.

------------------- Cheers but that wasn';t quite what I meant, the maths is quite easy, what isn't is deciding which is best. I've not yet seen a 32" LCD that matches the picture quality om my 28" sony trinatron, sure when it dies I guess I'll have to go for a LCD, but until then it'll never be worth me 'upgrading' because of the energy I'll save. Last year I put my 24" hitchi in storage which I brought in 1988, still working but I was given the sony. When the sony dies, I'll have to judge whether it's worth repairing or not based on the cost of repair and the quality of image, I really wouldn't factor in the energy usage. Unless anyone shows me a quality LCD or plasma, I find LCDs a bit jaggy with fast motion and plasmas a bit blurry. I aslo keep a lots of crap such as a clock, weather station, joss sticks etc... akll on top of the large CRT box, bloody LCDs are to thin to put my crap on ;-(

NT