sharp 14 inch tv

[brookster]

I know this is gonna be a long shot but seeing as you guys have come up trumps in the past i thought id give it a go.

The wife bought a Sharp 14 inch portable whilst she was at uni some 10 years ago - i know, 10 years why am i bothering, but it was fine till a couple of days ago. The tv was turned off by the remote and left on standby through the night - as it has been many times before, and then switched off by the power button in the morning, however when it came to switching on again nothing is happening. The switch is clicking as normal but no power seems to be getting to the tv. Ive checked the fuse in the plug and the socket and all is well - just no light or anything on the tv?? Anybody got any suggestions or should i just bite the bullet and invest in a new one (bearing in mind im a tight yorkshireman!)

Thanks.

 

[ninebob]

Maybe there's an internal fuse?

Trouble with TVs is that the internal parts can retain some startling voltages even when not connected to the mains, so it's not advisable to poke around inside them unless you really know what you're doing.

So I guess you have to question whether it's worth taking it to a repairer, bearing in mind a brand new portable from Asda or such-like is only 40-odd quid...

 

[brookster]

thanks ninebob, will have to blow the cobwebs off the old wallet i reckon.

 

[Thermo]

just had exactly the same thing happen to our old faithful grundig. Guy looked at it and said the power transformer was gone. Cost was about £140 to replace, so its at the dump and off to asda we go!

Thermo

 

[masona]

The tv was turned off by the remote and left on standby through the night -

I was listerning to the radio the other day and they said leaving the TV on standby is using the same amount of electricity as if it was on, so you should turn it off.

Does anyone know if it's true or false ??

 

[breezer]

i would say not quite true, the transformer is on, to run the remote (how elese are you going to turn it on?) but i would have thought something must turn off something (ht side) so there will be less current drawn, but i suppose not that much difference. Hva never metered a tv so dont actually know

 

[big-all]

ok i am sad i have several tellies
matsui 75w on standby 3w
seg-----38w------------9w
fergison 45w-----------4w
naiko---34w-----------10w
alba----32w------------6w

so average consumption45w
average standby----6.5
so the average consumption on standby is about one seventh
so all my tellies on standby dont = one on full power

but 6.5 watts x 24 =156 x 365=57 kw a year on stanby

 

[Gees]

Here is one I CAN answer........
There are resistors in the startup circuit that DO go Open circuit.
This is almost CERTAIN to be the problem.. However you will need someone to replace them for you

 

[breezer]

resitors rarely go open circuit (unless cooked by over voltage / current) its often transistors that go wrong

 

[Gees]

resitors rarely go open circuit (unless cooked by over voltage / current) its often transistors that go wrong

Sorry breezer but this time you are wrong.

Most modern tv sets have a driver chip and a FET in the PSU. No transistors at all in this cicuit but there are usually 2 or 3 resistors in series that supply the initial voltage to start the power suppy from cold. Once running the supply comes from the chopper transformer.
These resistors very often go open. I wish I had a tenner for everyone i've changed in the past as a professional TV repair engineer.

 

[breezer]

but from what you say that means i am still right, because i also said "unless cooked by over voltage / current" which they get on start up

 

[Gees]

No they are not cooked at all. They Just "go" while the set is running. All is then well untill you disconnect from the mains then it wont start up.They look to be absolutly fine.. no discolouration etc. they just "go"..

 

[breezer]

how odd, have you metrered one ? although i suppose it will be o / c

 

[ZenStalinist]

I believe I have a monitor with a similar problem then... and I was about to throw it away, I might check that, sounds worth fixing if that's the problem.

 

[Gees]

how odd, have you metrered one ? although i suppose it will be o / c

Yes they measure completly o/c. Usually just one of them the other (s) are not affected although they are only pence each and should all be replaced.