Re: LG TV 32LD650N - Slow to turn on. No display
Hey, real life got in the way of spending more time on this repair. But I hope to get back to it later in the year. I still have the TV disassembled on my workbench.
I will post again when I hopefully get some more time.
- Deltini...
deltini
New Member
Last Activity: 09-28-2020, 09:14 AM
Joined: 07-29-2020
Location: Syddanmark
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Re: LG TV 32LD650N - Slow to turn on. No display
Here are my observations so far.
The IC8101 (not a BGA, but a 48 pin LFQFP package, see image) pulls the base of transistor q8005 high to turn OFF the INV On/Off.
So when I turn on the tv and the LED is blinking, but there is no backlight. I measure 0.7 on the base of Q8005 (0v on the collector and emitter) this pulls INV on/off to 0v/GND. Otherwise the 3.3V_NORMAL line would make it high. And that is exactly what happens when I get the backlight to turn on using the on/off trick.
Then the voltage on...Leave a comment:
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Re: LG TV 32LD650N - Slow to turn on. No display
I have been able to get the TV to turn on by using the trick of waiting until it gets 'warm'. And then powering it off an on again. It didn't take as long as before, only about 5 minutes, but I don't know why.
Here are the measurements when the TV is ON:
[CODE]
+-------+------------+------+
| Pin # | Pin Name | Volt |
+-------+------------+------+
| 1 | Power-on | 3.2 |
| 18 | Inv on/off | 3 |
| 20 | A-dim | 1.6 |
| 22 | P-dim | 1.2 |
...Leave a comment:
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Re: LG TV 32LD650N - Slow to turn on. No display
Okay, I got all the caps soldered back in.
After I pressed the power button, the red LED is blinking and there is no backlight. Here are the voltages i measured when the TV is in that state.
[CODE]+----------+------------+------+
| Pin # | Pin Name | Volt |
+----------+------------+------+
| 1 | Power-on | 3.2 |
| 2-4 | 20v | 22.8 |
| 5-8 | GND | 0 |
| 9-12 | 3.5v | 3.4 |
| 13-16 | GND | 0 |
| 17,19,21 | 12v | 12.3 |...Leave a comment:
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Re: LG TV 32LD650N - Slow to turn on. No display
Thanks for the schematic. That’s great. Where did you find that?
I will try to get the re-soldering of the caps done today so I can get you a read out of the voltages on the pins....Leave a comment:
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Re: LG TV 32LD650N - Slow to turn on. No display
Thanks for the reply.
1) Here are some new pictures of the power board. I only posted the other one, because it was the only one I had, before de-soldering the caps. This picture has the caps de-soldered. I hope that's okay.
2) Uploaded a picture of the pin-out of the 24 pin connector.
3) Also uploaded, showing the power and main board on the back of the tv. The two multi-cables at the bottom of the main board goes to the speakers(the left one). And the side-panel buttons and the standby...Leave a comment:
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LG TV 32LD650N - Slow to turn on. No display
I have an LG TV model 32LD650N. It's about 9 years old. The last year it has been slower and slower to turn on. When I power it on, the red LED flashes (normal during power on) but the screen stays off. After ~15 minutes turning if off and on again would make the screen go on. The TV would work fine from there.
But now it just stays on the blinking power LED trying to turn on.
[B][SIZE="3"]What I have tried:[/SIZE][/B]
I am very much a beginner when it comes to electronics repair. But I suspected a bad capacitor on the power-supply.
After disassembly... -
Re: New Members - please post your introductions here
My old LG tv has brought me here. I'm hope to repair it and give it new life. Looking forward to reading and learning here.Leave a comment:
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