sony trinitron fault. pic on/off

cruiser27 · 14-03-2009, 12:28 AM

i have an 9 year old Sony trinitron.

recently developed a fault

the screen will go black for a few seconds then the picture returns. there is still sound when this happens

would this cost a lot to repair?

seems a shame to dump it

thanks

Sheepking · 14-03-2009, 9:22 AM

Sounds like it might be a dry solder joint. not huge job to fix it.

Also, Trinitron is the name Sony gave to their tubes and is not the model number. Sony TV model numbers back in the mid-late 90's started with a K (i used to work in a sony centre in a past life)

cruiser27 · 14-03-2009, 3:28 PM

Quote:

Originally Posted by Sheepking

Sounds like it might be a dry solder joint. not huge job to fix it.

Also, Trinitron is the name Sony gave to their tubes and is not the model number. Sony TV model numbers back in the mid-late 90's started with a K (i used to work in a sony centre in a past life)

thanks. yeah its a KV-29 FX 11U

so worth calling the repair man then you think?

Sheepking · 14-03-2009, 8:05 PM

Quote:

Originally Posted by cruiser27

thanks. yeah its a KV-29 FX 11U

so worth calling the repair man then you think?

If its a quick solder job then i'd think so (as long as you're still happy with the picture)

It could be a good excuse to upgrade to a shiny new widescreen plasma though

midiwife · 17-05-2009, 5:26 PM

I've got the same problem but it seems to clear up after the TV's been on a while. This time to no flicker though seems to be getting longer...

Could it be a dry solder? And is it something one could attempt to sort?

Any ideas welcome.

JayCee · 17-05-2009, 6:19 PM

Quote:

Originally Posted by midiwife

Could it be a dry solder?

No, dry joints aren't temperature sensitive.
Sounds like a faulty component.

midiwife · 17-05-2009, 6:40 PM

Cheers for the info JayCee.

I'll look out for a replacement set then as the colour's also going a bit.

mikejjj · 17-05-2009, 7:56 PM

Almost certainly a dry joint, having been a Sony engineer for many years i'll bet my wife on it !

midiwife · 18-05-2009, 9:48 AM

But... how would I set about trying to mend it??? How would I even find it? And, what about the colour business? I could well end up being more cost effective to source a replacement. But, I don't like widescreens so replacements are likely to be of around the same vintage... possibly with similar problems.

Chelsea_Fan · 18-05-2009, 11:56 AM

Quote:

Originally Posted by midiwife

But... how would I set about trying to mend it??? How would I even find it? And, what about the colour business? I could well end up being more cost effective to source a replacement. But, I don't like widescreens so replacements are likely to be of around the same vintage... possibly with similar problems.

On the Sony KV series you can access the service menu via the remote with a secret combination of buttons.

This gives you access tot tweak the geometry, the colour settings and the individual colour guns. Also you can mess around with sound and look at service info.

I don't know if these TVs have a gating mode when there is a fault but many older TVs used to gate on and off (via the PSU) if they detected a fault.

This made the picture turn on and off and it was done like this to prevent the TV from damaging itself further during a fault.

If it's had a useful life I'd bin it unless you can repair it yourself. Repairing CRTs can be hazardous (electric shock hazard).

Otherwise you are going to end up paying a huge hourly repair bill plus parts for a TV that is beyond its design lifetime.

Quote:

No, dry joints aren't temperature sensitive.
Sounds like a faulty component.

Poor solder joints can be VERY temperature sensitive. Especially if the temperature change is rapid and there are parts of a CRT TV where this is the case.

However, it could equally be a component, eg a capacitor breaking down.

Or it could be damp/dust causing breakdown.

JayCee · 18-05-2009, 3:18 PM

In my 40 odd years of repairing all types and makes of TVs I think I've accumulated a wee bit of knowledge and experience

The OP stated...

"I've got the same problem but it seems to clear up after the TV's been on a while. This time to no flicker though seems to be getting longer...
Could it be a dry solder?"

This is more than likely to be a low emission crt or a high esr capacitor probably in the psu or frame output stage....the giveaway part is "it seems to clear up after the TV's been on a while".
I reiterate this is not likely to be a dry joint in this case.

Chelsea_Fan · 18-05-2009, 5:48 PM

Quote:

Originally Posted by JayCee

In my 40 odd years of repairing all types and makes of TVs I think I've accumulated a wee bit of knowledge and experience

The OP stated...

"I've got the same problem but it seems to clear up after the TV's been on a while. This time to no flicker though seems to be getting longer...
Could it be a dry solder?"

This is more than likely to be a low emission crt or a high esr capacitor probably in the psu or frame output stage....the giveaway part is "it seems to clear up after the TV's been on a while".
I reiterate this is not likely to be a dry joint in this case.

Fair enough, you sound like you know a thing or two about TVs

Quote:

No, dry joints aren't temperature sensitive.

However, the above isn't strictly true. I also have an electronics background (not TVs) and I was making the general point that I've seen plenty of poor solder joints respond to temperature cycling. Eg putting circuitboards in a Thermotron chamber and cycling them from +50degC to -20degC and back a few times is a great way to find components that aren't soldered very well.

But that's on new boards. I guess the collapsing TV picture problem would have more likely shown up sooner if it was a poor solder joint rather than 9 years down the line.