No Picture or Audio on Insignia NS-LCD26

**adlegs** · 10-17-2012, 04:44 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by budm

Can we see good clear pictures of both sides of the power board? Also, what is the full model number of this TV, Insignia will have the main model number and follow by the - xx for the year.

Here are the pics... let me know if they are good. Thx

Attached Files

**adlegs** · 10-17-2012, 07:10 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by budm

Can we see good clear pictures of both sides of the power board? Also, what is the full model number of this TV, Insignia will have the main model number and follow by the - xx for the year.

here is the info

Attached Files

**budm** · 10-17-2012, 08:38 PM

Re: No Picture or Audio on Insignia NS-LCD26

Do the connectors on the power supply board has any voltage labels on them to tell us what the pins are?

**adlegs** · 10-17-2012, 09:05 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by budm

Do the connectors on the power supply board has any voltage labels on them to tell us what the pins are?

No there are no voltage markings on the Power Board. I checked the voltage readings at the Main Board.

Attached Files

**adlegs** · 10-17-2012, 09:14 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by adlegs

No there are no voltage markings on the Power Board. I checked the voltage readings at the Main Board.

Here are the Main Board connectors

Attached Files

**adlegs** · 10-17-2012, 09:28 PM

Re: No Picture or Audio on Insignia NS-LCD26

more...

Attached Files

**budm** · 10-17-2012, 09:41 PM

Re: No Picture or Audio on Insignia NS-LCD26

Thanks, good pictures, I can read the labels!
So the pin you will want to test is the STBY pin of the 11-pin connector of the main board. This pin sends the ON/OFF signal to the power supply board to turn on the 12v/24v power supply section.
I expect to see 0V when TV is off, and around 3V or more when the TV is powered up. so monitor that pin

**adlegs** · 10-18-2012, 04:59 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by budm

Thanks, good pictures, I can read the labels!
So the pin you will want to test is the STBY pin of the 11-pin connector of the main board. This pin sends the ON/OFF signal to the power supply board to turn on the 12v/24v power supply section.
I expect to see 0V when TV is off, and around 3V or more when the TV is powered up. so monitor that pin

0V off and 3.3V when powered on.

**budm** · 10-18-2012, 05:49 PM

Re: No Picture or Audio on Insignia NS-LCD26

OK, the Power supply on is generated OK by the main board, then we need to find out if the the PFC and the 24V power supply do turn on or not, you can see at the bottom of the power supply where the 24V outputs are, see if you do get the 24V there. For the backlights to come on, it needs the 24V that you will be checking, and the BKON signal on the 3-pin connector of the main board as shown in picture #2 of post 26. If you have both of the signal, then the backlights should light up.

**adlegs** · 10-18-2012, 07:01 PM

Re: No Picture or Audio on Insignia NS-LCD26

Ok I have the 24V on both pins on pic #1 post#25 but I have nothing on the BKON pin (pin 3). What should I have on the BKON?

**adlegs** · 10-18-2012, 07:04 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by budm

OK, the Power supply on is generated OK by the main board, then we need to find out if the the PFC and the 24V power supply do turn on or not, you can see at the bottom of the power supply where the 24V outputs are, see if you do get the 24V there. For the backlights to come on, it needs the 24V that you will be checking, and the BKON signal on the 3-pin connector of the main board as shown in picture #2 of post 26. If you have both of the signal, then the backlights should light up.

Ok I have the 24V on both pins on pic #1 post#25 but I have nothing on the BKON pin 0V (pin 3). What should I have on the BKON?

**adlegs** · 10-18-2012, 08:11 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by adlegs

Ok I have the 24V on both pins on pic #1 post#25 but I have nothing on the BKON pin 0V (pin 3). What should I have on the BKON?

Update.... I used a jumper and fed 3.3V to the BKON pin and the backlights came on. So is this a power board or main board issue??

**budm** · 10-18-2012, 08:34 PM

Re: No Picture or Audio on Insignia NS-LCD26

That means the main board does not send out the BK_ON signal, good news your power supply and backlights inverter are OK.
Next thing will be to find out if any LDO regulators are bad checking the voltages.
Since now you have backlights, do you see any pictures on the screen, if it is just the BKON circuit is bad, then you should have everything else working.

**adlegs** · 10-18-2012, 10:01 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by budm

That means the main board does not send out the BK_ON signal, good news your power supply and backlights inverter are OK.
Next thing will be to find out if any LDO regulators are bad checking the voltages.
Since now you have backlights, do you see any pictures on the screen, if it is just the BKON circuit is bad, then you should have everything else working.

I only have a back lit screen no picture. It looks like when I apply the 3.3V it just backlights the screen...
And thank you for taking your time to assist me in troubleshooting this issue. I really appreciate it!!!

**budm** · 10-18-2012, 10:06 PM

Re: No Picture or Audio on Insignia NS-LCD26

That means it may be just bad power supply some where on the board. We need to look for fuses and LDO regulator next. How much is the new board for this 26" inch?

**adlegs** · 10-18-2012, 10:14 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by budm

That means it may be just bad power supply some where on the board. We need to look for fuses and LDO regulator next. How much is the new board for this 26" inch?

I checked the AC fuse on the power supply board? How do I check the LDO regulator?
The power Supply board is $25-$35 If this is the issue I will just purchase a new one.

**budm** · 10-18-2012, 10:36 PM

Re: No Picture or Audio on Insignia NS-LCD26

The power supply board is OK, the power supply section of the main board is the one you have to check.
They are 3-pin device with big tab on the top, I can see one on the left side of the board by the black heatsink.
You just label the pin as 1, 2, and 3 as looking at it with the big tab on top. Measure the voltage on each pin with ref to ground.

**adlegs** · 10-19-2012, 03:28 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by budm

The power supply board is OK, the power supply section of the main board is the one you have to check.
They are 3-pin device with big tab on the top, I can see one on the left side of the board by the black heatsink.
You just label the pin as 1, 2, and 3 as looking at it with the big tab on top. Measure the voltage on each pin with ref to ground.

Left to right pin 1 0V pin 2 3.3V pin 3 5.10V

**adlegs** · 10-19-2012, 03:31 PM

Re: No Picture or Audio on Insignia NS-LCD26

Originally posted by adlegs

Left to right pin 1 0V pin 2 3.3V pin 3 5.10V

pic

Attached Files

**budm** · 10-19-2012, 06:25 PM

Re: No Picture or Audio on Insignia NS-LCD26

That voltage is OK, it is a 3.3V regulator.

No Picture or Audio on Insignia NS-LCD26

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