TV ticking and flicking
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Discussion

jgmadkit

Original Poster:

553 posts

279 months

Thursday 13th October 2005
quotequote all
I guess this will be classed as 'stuff' so I'll post this here.

My Tosh TV has started to make a ticking noise with the screen flicking at the same time when I first turn it on. It does this for about a minute then it is ok. The TV is over 10 years old now but it has only just started doing this.

Is it on it's way out or is there hope for it (ie an easy repairman fix)

I don't want to replace it if at all possible.

Ta, John

malman

2,258 posts

289 months

Thursday 13th October 2005
quotequote all
Sounds like main power supply. Probably fixable though.
Works when it warms up so could just be a dry joint somewhere. Find a friendly local repair man and see if you can get a free estimate.

philthy

4,697 posts

270 months

Thursday 13th October 2005
quotequote all
Th "tick" that you're hearing is the high voltage side of the screen. It could be nothing to worry about. Is the room it's in damp? has it been in storage for a while?
The flicker on screen is because the anode voltage drops slightly as it arcs somewhere. Keep using it, it might go away. One thing is certain, if it decides to let go, you will hear it when it does !

Phil

jgmadkit

Original Poster:

553 posts

279 months

Thursday 13th October 2005
quotequote all
Hi, no not damp and been in constant use for 10+ years.

You've got me worried now though as I don't want it to 'let go' whilst the kids are watching it.

Cheers, John

rfisher

5,064 posts

313 months

Thursday 13th October 2005
quotequote all
Buy a new one - 10 years is pretty good going.

It's going to go bang 'n' flash soon.

The noise could be the line output capacitor or transformer arcing. Either way it's 20,000 volts jumping around inside yer telly.

philthy

4,697 posts

270 months

Thursday 13th October 2005
quotequote all
rfisher said:
Buy a new one - 10 years is pretty good going.

It's going to go bang 'n' flash soon.

The noise could be the line output capacitor or transformer arcing. Either way it's 20,000 volts jumping around inside yer telly.



I didn't mean to worry you. But when they do let rip it is a pretty impressive noise.

Phil

jgmadkit

Original Poster:

553 posts

279 months

Thursday 13th October 2005
quotequote all
I'm guessing if it's going to let go it will be when I first turn it on when it's actually doing the flicking/ticking. It's worse when you first switch on then the ticking/flicking gradually gets less over the course of about a minute and then everything is fine, you wouldn't think there was a problem with it at any other time.

Oh well, may well start looking for a replacement.

Cheers everyone, John

Pigeon

18,535 posts

276 months

Thursday 13th October 2005
quotequote all
I don't think it's an impending component failure in the HT circuit because it gets better after it's been on a bit. If it is a flashover effect it's probably just due to dust, in which case the cure is to take the back off after it's sat off overnight and give it a jolly good hoover out.

The other possibility, as has been mentioned, is a dodgy soldered connection, which is trivial to fix, but needs fixing as it'll get worse and probably end up taking out some highly-stressed component.

philthy

4,697 posts

270 months

Friday 14th October 2005
quotequote all
As Pigeon says, it could be due to dust. As the HT side arcs across the dust it carbonises it, making it easier to do it again next time.
There is a possible remedy, but not one that I'd advise if you're not tech savvy. It involves removing the HT cap from the anode, cleaning the cap, and surrounding area amd leads with meths. This is very dodgy if you don't know what you're doing as the tube itself retains a VERY high charge. I used to have a large screwdriver that I grounded against the chassis (hard to find nowadays) and worked under the HT cap to ground the tube out. When it arcs (and it will) the "tick" you hear when you turn it on will happen again, only this time it will be to the end of the screwdriver you are holding. If it manages to find you in the circuit somewhere it doesn't half make you jump.
A TV engineer will clean it in minutes, what they are charging nowadays I don't know,it might cure it, it might not.
Phil

Pigeon

18,535 posts

276 months

Friday 14th October 2005
quotequote all
philthy said:
I used to have a large screwdriver that I grounded against the chassis (hard to find nowadays) and worked under the HT cap to ground the tube out. When it arcs (and it will) the "tick" you hear when you turn it on will happen again, only this time it will be to the end of the screwdriver you are holding. If it manages to find you in the circuit somewhere it doesn't half make you jump.

Yes, I remember discovering that when I was about 8. I can't remember what I said; I didn't know the right words at the time

Fortunately you don't always need to go that far - a good hoover and brush without actually taking anything apart (except for taking the back off) is often enough. Then go to the meths if it hasn't fixed it - of course since you've just been running it to test it it'll be fully charged...

jgmadkit

Original Poster:

553 posts

279 months

Saturday 15th October 2005
quotequote all
I'll give it a go with the hoover but I think I'll give the other bit a miss

Cheers guys