Insignia NS-43DR620NA18 standby light blinking

[earz]

I've got this Insignia NS-43DR620NA18 that has a blinking standby light after you push the power button (via remote or TV) but will not power on. No backlight, no image (flashlight test). I see that ShopJimmy offers a repair "kit" that replaces ALL boards but I'd like to try to pinpoint the exact issue if possible.

The PS fuse has 120VAC going through it. No bulging caps or discoloration can be seen. The following voltages were measured at the PS connector with the wiring still connected to the main board. Voltages in parenthesis were measured after power button pressed.

• ON/OFF - 0 (3.3v)
• NC - 0
• +16V_A - 0
• GND - 0
• GND - 16.5V
• +16V - 16.5V
• +16V - 16.5V
• +5V - 0.1V
• DIM - 0 (1.9V)
• PS_ON - 3.4V
• +16V_A - 0
• GND - 0
• GND - 16.5V
• +16V - 16.5V
• +16V - 16.5V
• +5V - 0.1V

I'm not sure where to go from here. It's odd that the two GND pins have 16.5v on them. Not sure if the board was misprinted or if there's something shorted to ground? I've also attached photos of the PS board (from ShopJimmy) as it's a clearer photo than I took, but mine looks the same.

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

A little update. I just went back down to my workbench and noticed that I’d left the TV plugged in for 10-15 minutes. I pressed the power button and I heard some audio through the speakers and then the standby light did two quick flashes with a pause between. Trying the remote, adjusting volume and pressing home button produces sound from the speakers. I was also able to verify that there is some words on the screen using the flashlight method.

I measured voltage at the backlight connector. The +VLED pins have 27.9V on each pin. Tried with the wiring plugged in and unhooked. No change.

I retested voltages at the main board wiring connector. The only change was the two +5V pins now read .3v

[jjanssen7]

Re: Insignia NS-43DR620NA18 standby light blinking

I'd look into the condition of the LEDS. They are a common failure on this model.

[budm]

Re: Insignia NS-43DR620NA18 standby light blinking

Can we see the pictures of the whole backside of the TV showing all the boards?
Please use attachment function to load the pictures, not using in line pictures.
BTW, You need to verify your readings. Are you sure you count the pin correctly? For example, how can you have 16.5V on Ground pins?
ON/OFF - 0 (3.3v)
NC - 0
+16V_A - 0
GND - 0
GND - 16.5V
+16V - 16.5V
+16V - 16.5V
+5V - 0.1V
DIM - 0 (1.9V)
PS_ON - 3.4V
+16V_A - 0
GND - 0
GND - 16.5V
+16V - 16.5V
+16V - 16.5V
+5V - 0.1V

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

Can we see the pictures of the whole backside of the TV showing all the boards?
Please use attachment function to load the pictures, not using in line pictures.
BTW, You need to verify your readings. Are you sure you count the pin correctly?

So it appears that the markings on the top side of the board are wrong. Looking at the bottom of the board, you'll see that the two GND pins are next to the NC pin, followed by the +16V_A pins. The top side of the board is marked differently.

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

Someone mentioned LED strips. Is there a way to test the strips prior to pulling the panel out of this thing? The LED connector has four +LED pins which each measure 27.9V. The connector also has eight -LED pins. ShopJimmy lists a set of 5 strips for this model. Each strip has 10 LEDs according to the photos on their site. So if 10 LEDs per strip are connected in series, it’d mKe sense that they’d be 2.8-3.0V LEDs being powered by the 27.9V but I’m curious how the 5th strip gets power? There’s only 4 +LED pins.

[budm]

Re: Insignia NS-43DR620NA18 standby light blinking

1) Retest the connector using the label marked on the bottom of the board and report the readings.
2) The 27.9V is the feeding Voltage to the Boost converter to boost the Voltage up high enough to bias on the LED. If ON/OFF control from the main board is not present then you will not have the boosted Voltage for the LED.
3) Keep black meter probe on chassis, Red probe on the LED+ then turn the TV on while watching the meter to see how high the Voltage jumps up to before settling down to 27.9V.
4) You should have LED strip tester to test the LED strips.

[budm]

Re: Insignia NS-43DR620NA18 standby light blinking

BTW, I need closed up picture around the LED connector to see how many wires it has and what pins the wires are connected to.

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

Measuring voltages per markings on the bottom of the board is the same as before, but here's the updated labels.

ON/OFF - 0 (3.3v)
NC - 0
GND - 0
GND - 0
+16V_A - 16.5V
+16V - 16.5V
+16V - 16.5V
+5V - 0.1V
DIM - 0 (1.9V)
PS_ON - 3.4V
GND - 0
GND - 0
+16V_A - 16.5V
+16V - 16.5V
+16V - 16.5V
+5V - 0.1V

Just now when I powered the TV on, I still get the two quick flashes from the standby light, but this time I don't get any voltage on the LED connector. I've attached a photo of the wiring to the LED strips. It looks like each strip is wired in parallel. The first and last pin have two red (+) wires. The second pin has one red wire. The black wires are bundled into two pins, but looking at the circuit traces on the bottom of the board, 4 of the negative pins are all on the same circuit trace.

[budm]

Re: Insignia NS-43DR620NA18 standby light blinking

So ON/OFF (BL-ON) and DIM control signals are fine.
There two sets of LED strings, the Anodes of each set of the LED strings are connected to the common boost converter output LED +, the Cathode (LED -) of each set of the LED strings are connected to U8505 and U8506 for maintaining the constant current through each set of the LED strings.
So:
1) Keep black meter probe on chassis, Red probe on the LED+ then turn the TV on while watching the meter to see how high the Voltage jumps up to before settling down to 27.9V..
2) Keep black meter probe on chassis, Red probe on the LED - then turn the TV on while watching the meter to see how high the Voltage jumps up to before settling down, you need to do this twice since you have two set of the LED strings.

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

+LED - 44.2V before settling at 28v
-LED1 - 0
-LED2 - 0

I’m guessing that I’m getting no voltage on either -LED pin due to one/many bad LEDs (open circuit) on one of the strips?

[budm]

Re: Insignia NS-43DR620NA18 standby light blinking

+LED - 44.2V before settling at 28v
-LED1 - 0
-LED2 - 0

I'm guessing that I'm getting no voltage on either -LED pin due to one/many bad LEDs (open circuit) on one of the strips?

So LED - never jump up at all when TV is turned on, correct? It looks like you have open circuits in the LED strings. If you are going to do more TV repair, it will be good idea to have LED tester.

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

So LED - never jump up at all when TV is turned on, correct? It looks like you have open circuits in the LED strings. If you are going to do more TV repair, it will be good idea to have LED tester.

I pulled the panel and was able to use the diode/continuity setting on my DVOM to test each individual LED on each strip. There was a bad LED on each strip. I had some replacement LED's on hand from a previous repair so I went ahead and swapped out those 5 LEDs. I anticipate that another LED is likely to fail on one or all of the strips at some point, but this may get me along for a while longer until the replacement strips are back in stock at shopJimmy. The only indication that there's anything different is the slight discoloring from my hot air gun.

Thanks for the guidance budm.

[budm]

Re: Insignia NS-43DR620NA18 standby light blinking

That was fast! You should also set the backlights level to as low as possible to extend the life of the LEDs.

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

That was fast! You should also set the backlights level to as low as possible to extend the life of the LEDs.

Will do. Got to love freebie TVs that people are throwing out. This will go in my office. It's a little bigger than what I've got in there.

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

So I've been using this TV daily for the past two weeks. I'm only using it as a second display for my laptop. Everything seems to work fine on it but every couple minutes the standby light flashes 6 times. I assume this is an error code? Does anyone know what this code means?

[nomoresonys]

Re: Insignia NS-43DR620NA18 standby light blinking

Wonder if you need to go in and clear out some errors that could be there from before the repair??

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

Wonder if you need to go in and clear out some errors that could be there from before the repair??

Possibly. How do I clear errors?

[nomoresonys]

Re: Insignia NS-43DR620NA18 standby light blinking

Might be best policy to try a factory reset and a firmware update before messing around in service menu tho.

[earz]

Re: Insignia NS-43DR620NA18 standby light blinking

Did a factory reset and it appears to have cleared the flashing standby light. Thanks for the suggestion.