Elderly friend - 60 miles away called to say the picture on his old 28" Sony Trinitron (about 20 years old) is collapsed into a narrow band. Sometimes it is okay for a while after switching on.
I seem to recall this is a sign of a HT fault - maybe LCD beckons.
Am I correct on my judgement? Is it worth calling a repair bloke to it?
The intermittent nature of this could suggest a dry joint somewhere in the deflection system; but 20-yr telly, 60 miles away... well, should be bread-and-butter for a repair guy (if you can find one), but I'd personally look to a new set.
Unlikely to be HT fault if the only symptom is narrowing. Would also be useful to know how quickly it transitions from full width to narrow. If HT is involved, it will take 1-2 seconds for the tube capacitance to change the HT voltage, whereas a bad connection on the scan coil circuit would be instant. I would suggest trying thumping the side of the set -- if it's a bad connection on the scan coil plug or similar, that might make it flick back.
LCD 's are great, but an old coot with limited means can probably happily enjoy a £50 CRT - there's loads of large ones going cheap due to plasma-fever
If its a horizontal band, then its a frame scan problem. Not HT. Might just be a bad joint - I say just, as they can be quite evasive sometimes.
Repair? Cheaper to get another old CRT. Might find another trinitron, nice tubes in some respects. Big problem with trinitrons is emission, but contrary to popular opinion that is fixable.
They're actually not that much lower in power consumption. Plasmas are higher.
An LCD has a fairly constant power consumption due to the backlight. An equivalent CRT may have a higher peak current requirement, but this changes with picture level.
If the OP is keen on the affected person, a visit to the shops may be worthwhile. LCDs under 37" are considered cheap consumer items by the industry. One of the parameters that would worry me is daytime viewing, when LCDs I have watched do not excel (reduced contrast). Then there is the latency issue.
Similarly, younger Trinitrons (like the 28" Wega that I got for 40 GBP) suffer from various geometry and digital processing artifacts.
My suggestion: recommend to the elderly person a call to a local repairer or two for ideas on the cost of fixing. If that does not work, recommend a visit to the shops.
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 =3D 0.1kW x 2hrs =3D 0.2kWh per day =3D 73kWh / yr Price of electricity =3D 12p/kWh So annual energy cost =3D 73 x 12p =3D =A38.76 / yr If typical life expectancy of appliance =3D 8 yrs, thats =A370 per life of the product.
Now compare an LCD with 70w consumption cost/yr =3D =A36.13/yr =3D =A349/ 8yrs Difference =3D 70-49 =3D =A321
Difference in purchase price is greater, so the LCD never pays its savings back.
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