Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Thank you.. we'll see if I can trace something hahaha...
c00lman
Member
Last Activity: 12-04-2023, 03:40 PM
Joined: 06-15-2021
Location: Calgary
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Yeah. Was hoping there’s a back door trick into the service menu
. Order it from the US not sure if we can put the URL here lol
Unfortunately. It’s hard to get parts within canada.
It’s nice to get this baby back in service but it might cost a lot more than just to give up
Just the main board alone is around $100 + shipping + import fees etc.
Wish we have stores like that here. LolLeave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
hi, plugging the TV in goes immediately to that 1-1 blink then press and hold volume - and input buttons while pressing the power button does not do anything.. it continue to do the 1-1 blink LOL...Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
do we plug in the power first then press volume - and input together? when I plug in the power, the TV goes to the 1-1 blink
i will try it again later
thank you...Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Thanks.. that's what I'm thinking.. will put it in storage for now and hopefully I can find a working power supply to test it. since the back light seems to be working (not 100% confirmed as can't really open up and check each light hahaha).
or I might just sell it for parts.
Thank you again.Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Yup. Holding the input and volume down key longer does the same thing. It looks like going to boot and display the k but it shutdown after backlight flashed.
Also took a pic of the ic underneath the power supply. Are you referring to this one?...Last edited by c00lman; 07-04-2021, 04:03 PM.Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Yup. I will try it again tonight
. Just outside...
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Thank you for the reply, yeah.. I was hoping for a huge voltage or current difference on the strip to indicate it's a strip issue but they are almost identical
I will take a pic of the back of the power supply board.
That is the procedure I'm following, pressing the Input and Volume down while plugging the AC power, the main board LED will blink, then after few seconds, I will hear the power Hum indicating it's activating the backlight, then the back light will flicker then power supply shutdown and the...Last edited by c00lman; 07-03-2021, 03:58 PM.Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Tried to jump the power supply (bu5 and ps-on or bu5 and ps-on and pn-pow). But it does not activate or turn on the back light. The only way I can turn on the back light is via the force boot ch- and vol +.
Measuring from ground to led-k. L2 connectors
All pins are around 112 to 114 v.
From Leda and led k.
All pins are around 139 to 140v
Measuring the current on each strip (disconnecting it from the connector and putting the multi tester in series) I’m getting
...Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
I will Try to redo the measurements lol. This time. I will put the plus to the L1 connector and negative on the L2 connector with corresponding pins.
I’m also thinking of measuring the current on each LED strip by putting the multimeter in series and hopefully will get different readings. I am assuming if there’s any shorts on the individual LED, the current consumption should go up a bit. I’m also assuming the LEDs are in series. Unless my theory is flawed lol hahahaLeave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
I will measure the voltage again when force boot.
The initial measurement I did is from gnd to the pins. Not from the pins + and -
Let you knowLeave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
can't find a pic of this size with the screen removed LOL
to use the back light tester, i just put the positive on the LED1_A Pin then the black negative to the LED1_K pin. and when the LED light up, I noted the voltage on the tester. I'm assuming it's giving 197/198V on that one strip? then proceeded to LED2_A and LED2_K and so on up to LED16. all are showing 197/198V. if one strip is showing a different voltage then at least it should show that strip is defective. can we assume the backlight strips are ok? or maybe they...Last edited by c00lman; 06-30-2021, 11:29 PM.Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Got the backlight tester and tested all 16 strips.
They all light up and the voltage display is showing 197/198Volts.Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Thank you. So if I understand it, when testing using the backlight tester to test the strips. They should all have the same/similar voltage. If a strip is showing more voltage (or less) then we can assume the strip is bad?
Hopefully we don't need to go that far.. removing that panel will be a pain LOL as just the TV itself is heavy and removing the panel at the same time trying to not to break LOL hahahah...Last edited by c00lman; 06-30-2021, 01:40 PM.Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
To test the backlight, I'm assuming I will connect the backlight tester to the LED 1-A and LED 1-K which will be the + and - for the LED Strip? the power supply has 2 Connectors going to the LED strips. L1 connector is marked LED1-A, LED2-A, etc then L2 connector is marked LED1-K, LED2-k. once connected, I have to see if the backlight LED strip will light up right? through the small holes in the chassis? the test I'm going to do is to see if all strip will light up and not the individual LED lights right?
When we initially...Last edited by c00lman; 06-30-2021, 09:21 AM.Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
The TV is around 7-8 years old.
I dont have a back light tester, i can check and see if they are not that expensive that I can purchase. To test the back light strip, do we need to remove the panel/screen or can we do it just on the wire connector?
coz I've seen videos of repairing the strip but that involved removing the screen panel itself and that thing is delicate hahahd and removing a 90 inches screen is not going to be fun hahahah
I'm just checking the power supply...Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Yeah unfortunately pressing the input and volume down. The tv flash and the backlight flicker and then back to 1-1 blinks...Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Deleted, duplicate postLeave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Here are the pics of the board and connection. can't take the whole back as it's standing in the hallway and can't back out more hahaha :P
so it seems if we force it to boot up (Channel down and Volume UP), the TV works, can power off/on, change input, access menu etc. as long as we dont unplug it, it will work.
if we unplug it, then replug, it goes to the 1 slow 1 fast blink. the only way we can make it work is to do the force boot up when plugging in.
Also anyone has a schematic of the power...Leave a comment:
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Re: Sharp LC-90LE745U 3 slow and 1 fast Blink
Update:
I did the jumper again PIN 14 (PN-ON) and PIN 15 (BU5) without Jumping Pin 16 (PNL-POW). here are the voltages.
Connector to Main board
1-2 0V
5-8 13.05V
13 - 3.04V
14 - 4V
15 5.04V
rest are 0V
L1 Connector:
1 - 16 113V
L2 Connector:
1-26 0V
No Backlight.
when I plugged the Main board and do the force start - Power Channel Down and Volume up.
L1 Connector:
1 - 16 276V
L2 Connector:...Leave a comment:
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