> "Tron"
>
>>
>> Buying a new set would not be an easy fix.
>>
>> Surely there would be a fuse near the power supply to handle power
>> surges.
>
>
> ** Go find it and replace it, should be rated between 2 to 5 amps.
>
> Be sure to buy a "slow blow" type - will have the letter " T " in front
> of the amp rating.
>
I've finally got round to doing this. I've seen the warning on the back of the TV that says "Do not remove cover. Electric shock."
Two questions:
If I have the TV unplugged, is there no risk of electric shock?
Do I need to take off the whole back half of the TV just to look at the fuses near the power supply?
Don't do it if you haven't any knowledge or qualifications with electrical devices. Even with the set switched off and unplugged there are areas like the HT power supply that have large capacitors that hold their 16KV or more voltage for a very long time. It can trigger fibrillation of the heart.
Get a TV service person to do it - even if it is *only* a fuse. The important question is "why did the fuse blow?" replacing it might simply blow again and this time do some real damage.
If anything happened to you your insurance would be null and void as you are not an authorised person to do this.
If you don't know what you are doing, get an expert to do it.
-- Shill #2
I do not feel obliged to believe that the same God who has endowed us with sense, reason and intellect has intended us to forgo their use. Galileo Galilei
devices. Even with the set switched off and unplugged
their 16KV or more voltage for a very long time. It
for weeks.
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Capacitors / How Long can a Capacitor Hold a charge of energy?
That really depends on the impedance of the circuit around it, and its leakage rating. A really good Cap with nothing to drain off the energy can hold the voltage for a couple of days, maybe weeks, but most caps used in radios might hold their charge for a couple of hours if nothing is draining them
If you need to ask these basic question then you shouldn't be holding a screw driver let alone taking the back off a set. Call a qualified repairer and leave it alone.
front
back of
the
electrical devices. Even with the set switched off and unplugged
that hold their 16KV or more voltage for a very long time. It
been off for weeks.
leakage rating. A really good Cap with nothing to drain off
most caps used in radios might hold their charge for a couple
There is a risk, the CRT might still be holding voltage, and there is SOME possibility that other parts such as capacitors may be holding a charge still. (enough to bite you) I have had CRT's bite me after a couple of weeks of being disconnected. It is NOT fun.
You do have to remove the back to check the fuse on every set that I have seen in the last couple of decades, though im sure someone will find an exception.
(we did own an Astor set in the early 1970s that you could remove the fuse without taking the back off by unscrewing a white plastic clip on the back of the set that held the fuse.)
Its also very possible that there are 2 fuses, one on the incoming mains supply, and a smaller rated one on the output B+ rail of the power supply in the set.
If you are asking these questions, you should probably not be doing this job.
If you go ahead and do it, then I would advise removing the fuse (or its remains as the case may be) and replacing it with an insulated tool an insulated tool, and not with your fingers.
The fuse should be checked with a meter, I have seen fuses fail inside the end cap, and still look "ok" through the glass tube.
If it is blackened - then you will probably find the replacement will do the same too, as shorted out swichmode chopper transistors or Horizontal output transistors are a common fault and will usually provide a dead short across the mains.
The fuse should be checked with a meter, I have seen fuses fail inside the end cap, and still look "ok" through the glass tube.
** Ditto.
If it is blackened - then you will probably find the replacement will do the same too, as shorted out swichmode chopper transistors or Horizontal output transistors are a common fault and will usually provide a dead short across the mains.
** AC supply fuses in TVs and PC monitors are normally required to pass the huge current surge associated with the *de-gaussing coil * - this can easily be 30 - 40 amps peak all on its own !!
Combined with the initial charging surge of the filter caps in the PSU makes life pretty damn hard for a puny 20x5mm maybe 2.5 to 4 amp "T" fuse.
Also, if the degaussing thermistor becomes damaged by repeated switch on cycles - the same AC fuse will blow.
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The more service jobs I see, the less simple issues relating to AC fuse failures become.
I'm talking insurance claim - you would be blown out of the water by the insurance company if you were not 'authorised' to carry out repairs. Check your fine print. Australia is pretty lax on regulations compared to some parts of Europe where you can't even buy a power point socket unless you present a license - I believe it is on the agenda for discussion here.
It could only work at a Federal level and yes a great black market opportunity! I don't think it will happen. You can only go so far in trying to protect people from silly decisions. I think there is a lot of "I'm a bloke so I can do anything mentality" in tackling a range of home repairs.
I once saw a T.V. attached to a two-metre-long extension cord. The T.V. power cable had a socket and the extension cord had a plug at both ends. I pointed out the danger to the lady of the house but she said "My hubby fixed it" (no surprise there) "He knows all about those things".
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