Weird TV fault, any electronics experts / clairvoyants?

droopsnoot

Lumstorm wrote: »

It cost me £110 in total when they called to to tell me after their initial inspection to diagnose the fault,

Thanks, I'm not totally sure at that price whether I'd pay to have it repaired, or drop a bit more on a new LED TV. Would that last as long as this has? Probably not.

that wrote: »

I mean not plugged it, do not skimp and just switch it off at the mains.

Yes, I get that bit, I'd have to move it in any case to be able to get access to the back.

Heedtheadvice

Throwing good money after bad.......


Spending half the cost of a new tv on repairs on a device that will get other faults soon in all probability!


:rotfl: Not very MSE that........

that

Heedtheadvice wrote: »

Throwing good money after bad.......


Spending half the cost of a new tv on repairs on a device that will get other faults soon in all probability!


:rotfl: Not very MSE that........

Possibly, but if you do it yourself, especially after practising on an Audi, you should have the skills that cost £0. Slow and steady, and if it does not work after then you can still buy a new one, nothing to lose?!

Best day is a Thursday, because if you mess it up, there is always late night shopping where I am and possibly where you are too, not much good on either

Heedtheadvice

The chances are the OP does not
a) have the skills, knowledge or circuit to do a diagnosis
b) will not recognise if there is something likely to discharge it's contents such as an electrolytic capacitor
c) will not have an isolating transformer to isolate the chassis from mains
d) will not have the necessary tools or equipment essential to doing a proper diagnosis such as DMM, high voltage probe, oscilloscope, earthing wand etc.
will not know which parts of the circuit are the locations that can shock or electrocute
e) will not know how to align the set and test it out if a fix is possible
f) might not know where to or cannot source spares
g) unlike as you say, that, you do not pick up the necessary skills by "having a go" especially on the safety side!!

....and....and.....



Not really wanting to put a downer on enthusiasm or money saving but old TVs can be a sod to work on and would have expected the OP to value life. I have appropriate electronics experience, knowledge tools etc. and was in a similar position last year with a long living crt TV. Just bought a new Led one on the basis that it was not worth the time and effort to attempt a fix.

droopsnoot

a) correct-ish. I've a vague idea I have the service manual with circuit diagram somewhere, but that might be for my previous TV.
b) correct, though I can see when a capacitor is bulging (Vestel Freeview box owner) or if something was obviously burnt out. I suspect that wouldn't give such an intermittent fault, though.
c) correct
d) DMM yes (though fairly basic), others no.
e) correct
f) correct, unless eBay is one of those places.
g) Fair point.


It's not very MSE to pay good money to repair an old TV set, that's certainly true, but it's equally not very MSE to just chuck it out and buy a new one (that almost certainly won't last as long) at the first sign of trouble in the shape of a very intermittent fault. While the prospect of a shiny new TV is very appealing, I struggle to chuck out things that are basically OK virtually all the time. Of course, if the time between failures starts to decrease, then that changes.


Part of the reason for asking earlier what the other posters repair had cost was for comparison - the only time I've had it repaired before was still within the warranty period so of course there was no cost involved. The issue with sending it for repair (apart from I don't know if we have a local TV repairer, and I don't think it will fit in my car) is how to know whether they've fixed it, given how long it can go between failures. The same would apply to trying to fix it myself, unless I got the back off and there's an obvious thing.

Heedtheadvice

Well if you really are considering sending away, first consider carriage costs? Then add on for fix if you can find somewhere you trust!


Considering it's age then yes I agree that a new tv probably will not last as long but as was previously posted you must be at or heading rapidly towards the steeper part of the bathtub curve when TBF falls rapidly. Good luck!

droopsnoot

No, I'm not really thinking of sending it anywhere, especially by carrier / post, all that's going to achieve is to get it closer to the cost of a new one.


As much as anything, I was intrigued as to what the fault might be, and whether it might be relatively simple to fix. Mostly, that seems to be "not really".

that

Heedtheadvice wrote: »

The chances are the OP does not
a) have the skills, knowledge or circuit to do a diagnosis
b) will not recognise if there is something likely to discharge it's contents such as an electrolytic capacitor
c) will not have an isolating transformer to isolate the chassis from mains
d) will not have the necessary tools or equipment essential to doing a proper diagnosis such as DMM, high voltage probe, oscilloscope, earthing wand etc.
will not know which parts of the circuit are the locations that can shock or electrocute
e) will not know how to align the set and test it out if a fix is possible
f) might not know where to or cannot source spares
g) unlike as you say, that, you do not pick up the necessary skills by "having a go" especially on the safety side!!

....and....and.....



Not really wanting to put a downer on enthusiasm or money saving but old TVs can be a sod to work on and would have expected the OP to value life. I have appropriate electronics experience, knowledge tools etc. and was in a similar position last year with a long living crt TV. Just bought a new Led one on the basis that it was not worth the time and effort to attempt a fix.

a) No diagnosis needed, wax on wax off. Solder on, then sucked off (in some cases), then resoldered.
b) leave that old tv for a few hours and bet that tv will have little charge except for the tube. Besides, he should be soldering the joints, not shorting them out to find the brightest spark.
c) Won't be plugged in to mains, so no transformer needed. To be fair I did and still do have one, but never used it, just snip the earth on the soldering iron plug, and you are fixed, or an iron that connects through a transformer and you are good to go on a powered tv.
d) just a resolder job. Hopefully a careful resolder job. Probably only need a screwdriver to get the back off.
e) nothing to align. No test pattern gen needed, no tweeking of voltages, no yoke recoil removal
f) I'm sure he can find solder, flux for electronic use... and some 99% isopropryl (rubbing ) alcohol if he want to go a few extra yards to clean the board after soldering
g) If he makes a solder bridge either the tv will no longer work, or the fuse will pop. You could also argue by not fixing it that it could also start to spark more and burn which may also cause a fire.

If he cleans the bottom of the board with a toothbrush, and the top with the thin painbrush to remove the dust. With a bright light, you are usually able to see a bad joint often without a magnifying glass, and at this age there will probably have a few gnarley joints and may only end up only soldering a few.

just carefully start soldering, surely is better than just binning it?