Re: Insignia NS58DF620NA20 - have backlight but no picture
Just an update on this.
- I tried a replacement T-Con and it did not fix the problem.
- I tried 3 replacement main boards and they did not fix the problem.
At this point I'm thinking the main board is not the problem since 3 replacement boards all exhibited the same problem (I could see 1 replacement being bad, but not 3). So now I'm thinking either 1) I got a bad replacement T-Con, or 2) The panel itself is hosed.
I noticed when the TV is powering on, there's a green LED on...
Daveleone
Badcaps Veteran
Last Activity: 05-13-2023, 05:29 AM
Joined: 04-14-2016
Location: AZ
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Re: Insignia NS58DF620NA20 - have backlight but no picture
What do you guys think? Next steps?...Leave a comment:
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Re: Insignia NS58DF620NA20 - have backlight but no picture
Checked the test point. 12v present.
Ok, I tried this. If I disconnect the right ribbon, I still get a black screen. If I disconnect the left ribbon, I get half white / half black screen (see pic).
Another note: The TV will turn on and off with the remote. I tried pressing the different remote buttons (home, Netflix, etc) button to see if I could get anything on the screen in all 3 cases (both tcon ribbons connected, left disconnected, right disconnected) and...Leave a comment:
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Insignia NS58DF620NA20 - have backlight but no picture
Hi all! I have an Insignia NS58DF620NA20 TV here. When plugged in the power button illuminates blue. If I press the power button, the backlights turn on, but there is no picture. I can turn the TV on and off via the remote.
How can I check whether the problem is the t-con or the main board? Is there a way to test the t-con board independently of the main board on this set (eg. bring up a color-cycling test pattern)?
Thanks!... -
Re: Does anyone know what LEDs an LG 55LM5400 uses?
Yeah, not to mention, both the seller and Alibaba disagreed with me that those LED strips were unusable on my TV and refused to provide a refund. So that was $35 down the drain.
At least I got the TV fixed in the end....
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Re: LG OLED55C7P Vertical White Bar and Randomly Turns Off
To follow up - I replaced the panel and all is well (t-con and main board work fine). Case closed.Leave a comment:
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Re: LG OLED55C7P Vertical White Bar and Randomly Turns Off
1) [B]T-Con:[/B] Here are the best pics I could get. Had to break it into 2 shots (left and right) to get enough clarity to read the serigraphs. (see attached)
2) [B]Panel Driver Board:[/B] That board is behind the stiff metal backing plate that is fused to the panel (you can see what I mean at the bottom of the picture of the back of the TV from my first post), so there's no access to that board for pictures or repair - unless I take an angle grinder and cut away some of the metal frame
...Leave a comment:
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LG OLED55C7P Vertical White Bar and Randomly Turns Off
Hi All!
I have this LG OLED55C7P. Someone gave it to me stating that it would no longer turn on. I plugged it in and it turned on right away, ran it for a while and everything looked good. Gave it to a client of mine and that same day he said after watching it for an hour it shut off, so I had him bring it back. Now, it has a vertical white bar (see pics) and will randomly shut off - sometimes after an hour or two, sometimes after a few minutes, sometimes after a few seconds. I noticed that initially the white bar appeared solid, but now it looks streaky.
Looking for... -
Re: UN55D6900 BN44-00428B partial led driver circuit failure
Update:
- The first replacement power supply I received was all rusted & corroded. All I would get was a relay click on, then immediately off. No LED lights.
- The company sent a replacement board and the replacement was also defective. It would click on, make a high pitched whine, the LEDs would come on momentarily, then relay click off.
- Finally, the company sent a 3rd board and 3rd time's a charm, as they say! It works perfectly.
Took a month to get a working board, but...TV fixed....Leave a comment:
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Re: LG OLED 65EG9600 no picture
UPDATE: I finally got a replacement main board. Fixed. The original main board was the culprit.
Thanks for all your help, Diah!...Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Yes, you are correct, it should be Q9253. I think R_J had a typo, but I understood what he was looking for.
You're right, this was a mistake when I wrote my reply (sorry, I was running on 20 minutes sleep from the night before ). My statement should have read:
"...When I get the higher [B](130V-219V) [/B]voltage across R3+ to L3-, the voltage across R9265 is the [B]2.5V-2.6V [/B]reading."
I did some visual inspection and found...Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Yes (D9521), yes (bottom=anode, top=cathode), and yes (wrt ground). Sorry for not being more specific, I'm brand new to this and didn't know which side was the anode vs cathode. I had to Google it
Interestingly, sometimes when I read it it is fluctuating between 2.5v-2.6v. Other times it is 0V. I do notice the LEDs flickering when this happens. More below...
Ok, I checked across R3+ to L3- and it sometimes it reads -2.5v, other times it reads...Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Was testing with PSU & main connected.
Re-checked boost voltage and it still jumps up to 170V right after I apply power. But the LEDs don't come on when it's at that voltage. A moment later the voltage drops to 128V on the bad circuit and 160V on the good circuits, and that's when the LEDs on the good circuits turn on for the first time (then they turn off, then turn back on again as is evidently the normal boot cycle). The LEDs on the bad circuit never come on.
THIS is...Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Thanks for the reply. I have already verified that the LED strips are ok earlier in the thread. I attached these segments of the LED strips to a different driver circuit, and they worked fine, so the LED strips are not the problem here....Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Ok, I swapped IC9151 with the known working one from the other circuit. No change (the other circuits still work, the non-working circuit still does not work and has the same voltage readings). So, IC9151 was ok.
What next?...Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Update: R9264 was also blown out, so I went ahead and swapped R9263, R9264, R9265, and Q9253 out with the corresponding components from one of the working LED driver circuits so we can continue the debug of this non-working circuit (and I will replace the components in the known working circuit later once I receive the parts in the mail).
Now the voltages in this non-working circuit read as follows:[LIST][*]R9165 - this is the circuit that I cannibalized, so it's disabled.[*]Voltage drop across...Last edited by Daveleone; 08-07-2021, 01:46 PM.Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Well, I messed up and accidentally shorted that R9265 resistor and blew it. So, I'm going to give you the post-catastrophe numbers below. I rechecked the resistors and voltages around the diodes and those are still ok, so nothing I posted before has changed...
[LIST][*]Voltage drop across R9165=45.4mV, R9265=[COLOR="Red"]2.3V[/COLOR], R9635=45.5mV, R9645=45.2mV[*]If I read the voltages at the bottom and top of each resistor as compared to ground, I see:[LIST][*]R9165 -8.7mV (bottom), 36.7mV...Last edited by Daveleone; 08-05-2021, 11:07 PM.Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Both D9251 and R9251 check out ok (note: my multimeter only goes down to 0.1Ω, and it showed 0.3-0.4Ω for R9251, but I checked the other R9x51 resistors and they all read the same).
I monitored D9251 voltage when I powered on the TV. My multimeter sampling rate isn't the best, but I tried it a few times and did see it go up to 160-170V momentarily and then drop back to 126.8V and stay there.
For reference, the other LED driver circuits would jump up to ~160V, then drop back...Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
I made a little diagram to show the "R1+ to L1-" circuit, in case the text was still confusing....Leave a comment:
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Re: UN55D6900 BN44-00428B partial led driver circuit failure
Ok, the suspect LED driver circuit or LED segments were in the "R3+ to L3-" circuit. So, I swapped the wires from the "R3+ to L3-" circuit with the wires from the "R7+ to L7-" circuit. When I did that, LEDs previously attached to the "R3+ to L3-" circuit lit up properly, and the LEDs previously attached to the "R7+ to L7-" circuit did not. In other words, the problem is a faulty LED driver circuit, not the LEDs themselves.
Would appreciate your...Leave a comment:
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