Technika 26-207 26"LCDTV-sound no picture*UPDATE* opened unit and found........

[markie76]

Hi,

A friend of mine bought a Technika 26-207 26" HD Digital TV described as working but when he got it home and switched it on the blue LED comes on and you can hear sound but there is no picture. The screen is not smashed and it looks like the backlight does come on.

I was wondering if anyone had experience of this brand

or a user/service manual

or can offer advice on this sort of problem.

Thanks,

Mark.

[terminator2k2]

hi there, possibly uses the 17mbxx chassis....can you see a faint pic on the lcd screen at all when its switched on.?? is so sounds like the inverter board is at fault and needs replaceing....

[tv tony]

if this is the lcd2602 a more likely cause is the diode feeding the 24v line to the inverter, its nearly always dry and as a result gets hot till it eventually goes s\c.
although terminators post is equally plausible, many thanks
tv tony

[markie76]

I actually think the inverter is fine because the backlight is firing up - you can see slight light bleed around the edges of the screen. It just looks like no signal is being fed to the screen and it remains just black/blank.

Does the 17mbxx chasis suffer from a signal processing fault?

Thanks,

Mark.

[markie76]

We've taken it apart and found some interesting things. The main PCB: 17MB12, PSU board: 17PW22-4.

On the PSU board there has been some work done.

1. Some tracks have been repaired.
2. PL808 has a solder ball on the copper side but no socket topside. PL807 is empty also but it looks like thats how it left the factory.
3. 10uf 50v capacitor soldered between PL806? & PL822 on the underside.





The other most suspicious change is the cable which goes from the main PCB to the LCD panel looks like it has had some sort of Frankenstein job done on it - where it has been 'chopped' and resoldered at the main PCB end. However, some of the wires from the cable have large crimps on them which are just taped up. To me it looks like a cable from another unit (but fits the socket on the LCD panel) has been attempted to be adapted for the plug to this main PCB. See pics below.

 

Would any of you guys with experience of the 17mbxx chassis seen this done before or can think why this would be done?

As the tv powers up and processes sound (just blank screen) my starting point would be to get a new PCB to LCD cable.

The panel in this tv is a Samsung -

Any help much appreciated.

Thanks,

Mark.

[terminator2k2]

well that looks like the psu pcb has a crack in on it and thats why you see the repairs to the tracks etc....the power supply is up and running as you have sound and led is lit....

most cheap lcds suffer with problems with the lvds cable and is usualy cured by spraying the connectors with a bit of switch cleaner...this problem causes all kind of picture faults, but as you have seen the lvds cable looks in very bad shape, so i would try getting one of those first and then see what happens

[markie76]

You're right that was my thoughs aswell to either get a pin-out diagram of the correct cable or get a replacement.

I've contacted some suppliers about a replacement cable but all they offer is to make one if I send them the original - which I could do myself if I had it.

Do you know of any suppliers that can do a pin-out diagram (service manual) or new PCB to LCD cables?

THis unit has a Samsung panel - does Samsung provide the connector when they ship the LCD panel to the OEM or does the OEM make their own interconnect cables?

Its just quite frustrating when repair companies/parts suppliers don't respond...

[terminator2k2]

you could try contacting..

http://www.chsinteractive.co.uk/

you would of thought that all these things would be industry standard....would make sense really...also like most things in this trade if they all got there heads together and made things compatible with each other like the computer trade has done it wouldnt half be easier to repair these things.....