Insignia NS-L22Q-10A Dim back light

[gica69]

Hi guys found this in storage and plugged it in noticed dim light barely see the menu screen have to put it at an angle and during the day I can see the menu but barely. What could it be? Thanks to all that contribute.

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

I replaced some of the 1000uf caps and the 470uf caps on the power/inverter board and same story. I would like to test it myself have all the tools for it.

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

Here are the pictures

[vinceroger69]

Re: Insignia NS-L22Q-10A Dim back light

Have you tested the dc voltages on the power supply at the connector that goes to the mainboad? on the power pcb by that connector has it got any writing by the connector to show what the pins are for?

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

Thanks Vinceroger69
Testing the power supply at the connector from the main board I get the 5v and at the 12v wires I get 13v and that's all the time on or standby. At the Dimm I get 2.97v after the Please wait message and at the N/F wire I get 3.2v also after turn on all DC. I get some power on the 4 backlight connectors when the "Please Wait" message appears and then it drops.

[vinceroger69]

Re: Insignia NS-L22Q-10A Dim back light

Do not measure the connectors going to the backlight im sure this set uses ccfl lamps if it does measuring that high voltage will damage your meter and high risk of shock im sure a more experienced member will confirm this too. what is the part number on the transformer by the backlight connectors? in a dark room do you get a quick flash of light on the screen as the set powers on.

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

I get the Please Wait pop up screen really clear and on the back of the panel I see lights in 8 or so different spots, so yes I would say there's a quick falsh of light same time as the Please Wait one.
Thanks for the warning the meter is a Klein MM1000 and it self shut down on one occasion so it has protection but good to know.
Hope you can see the number from the picture below, I think it's 80TL22T-4-DN

[vinceroger69]

Re: Insignia NS-L22Q-10A Dim back light

ive been trying to find a data sheet for the transformer i have found a picture of one which maybe of use maybe a more experienced member will advise which pins you need to measure with the set unplugged and meter in ohms mode.Did you try the set in a dark room do you get a brief flash of light on the screen on power up.

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

Yes I did and it lights up briefly with the Please Wait message.

[vinceroger69]

Re: Insignia NS-L22Q-10A Dim back light

roughly 2 seconds?

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

Yes

[vinceroger69]

Re: Insignia NS-L22Q-10A Dim back light

have a read of this while were waiting for budm etc to advise on the windings we need you to check on that transformer
https://www.badcaps.net/forum/showthread.php?t=10419

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

Yes thanks for the reading, I recently ordered 4 ccfl lights to add to a pair of headlights on a car. Still have the off the car as per picture. Are these sufficient to test the LCD?

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

They're 12v input

[vinceroger69]

Re: Insignia NS-L22Q-10A Dim back light

you dont need to use the invertor part you could just use the ccfl tube and connect it to the psu conector.

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

OK here's what I found out by plugging in the inverter from the car lights. I get bright LCD lights on all but the blue/black top connector. It shows in the pics the pink/white turns it on but the other doesn't.

[vinceroger69]

Re: Insignia NS-L22Q-10A Dim back light

i would say a ccfl/or wiring on the top of the lcd has gone then so next step would be to strip the screen down to get too them but be really carefull as the lcd is really thin and cracks really easy also keep the diffuser layers in the right order etc and try not to get dirt/finger prints on them.
maybe look on youtube theres some great guides showing ccfl repairs.

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

Another thing I just noticed is a hissing sound by the connectors it's an electrical current sound like high voltage. One time when I unplugged the 2 good connectors at the bottom and one good at the top I looked and saw electric spark between the 2 wires individually at the connectors at the bottom. As if the 2 wires of each connector produced spark. Now if I plug all four I still hear a hissing sound.

[gica69]

Re: Insignia NS-L22Q-10A Dim back light

So you don't think the transformer is an issue anymore? Can't it run with just 3 CCFL lights?

[vinceroger69]

Re: Insignia NS-L22Q-10A Dim back light

Thats the high voltage from the transformer hence i said dont measure the connectors with a multimeter. My guess its one ccfl gone or the wiring you cant run it on three as the psu will sence a error and shut down so you really need to strip it down and look whats faulty. Personaly i cant even re sell sets of this size 22in and lower no one seems to want them no more as prefer larger sets. The replacement ccfl can be expensive too and you need to match the lengh and size as they all vary.