Re: attempt to clone LED TV Backlight Tester
I did not have this Tester.
He has it
cliff_hootarski : Got one and does exactly what it's supposed to do. Can test whole string or each LED individually. Just another tool in the arsenal.
LED Tester - How to Test LED Backlighting - SID GJ2C LED TV Backlight Tester
https://www.youtube.com/watch?v=4DS8_utsLPo
Check at 3:23, the tester shows 293V DC when it touchs one led it drops down to 2.0v then goes up.
Basically is a 300v 2.5ma current source, if more than 4ma the Tester shuts down and does soft start until it reaches 2.5ma
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Re: attempt to clone LED TV Backlight Tester
Can we see the straight shot of the bottom side of the board?Leave a comment:
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Re: attempt to clone LED TV Backlight Tester
Inside the Tester,Looks like this.
Similar to this circuit.
Transition-mode PFC controlle L6562A
https://cdn.badcaps-static.com/pdfs/...8e89c6f9ca.pdfAttached FilesLast edited by capwizard; 07-13-2016, 02:39 PM.Leave a comment:
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attempt to clone LED TV Backlight Tester
Im attempt to clone ShopJimmy SID GJ2C LED TV Backlight Tester.
Don't wanna spend money on another
electronic waste.
Can I use PWN IC from AC adapter or use PFC IC which most high-end TV power supply has to archive my goal.
I don't understand how could Tester can test one to 100 leds , is because the 2mA current feed back limitation,or they used big capacitor slowly charge up the Vstartup.
The max power is about 300v 200ma, 60w
Any help would be very appreciated.
ShopJimmy SID GJ2C LED TV Backlight Tester.
http://www.shopjimmy.com/sid-gj2c-le...ght-tester.htmAttached FilesLast edited by capwizard; 07-13-2016, 01:21 PM. -
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I bought this p2210f dell monitor to fix. Schematic is the same as p2210.
Behaviour is that monitors comes on but then backlight switches off almost instantly. If I look with flashlight I can still find the "No signal message". So definitely a backlight issue. Trying to advance the issue I proved that the protection circuit is switching off the backlight by shorting out C3 and resistor to disable the INL chip then re enable by removing the short.
This is where it gets interesting. When I disassembled the monitor to solder leads on c3 capacitor I noticed the backlight flickered... -
Hello all,
Am trying to figure out this backlight issue with this A1990 Macbook Pro.
Tests performed:
There is no backlight even with a good screen.
Backlight IC is receiving the correct support voltages.
Fuse F8400 ok
Current sense resistor R8400 ok
Backlight IC is receiving 3.3V on enable pin.
Backlight IC receiving voltage from PPBUS_G3H, aprox 12.5V.
Backlight IC receiving 5V from PP5V_G3S
Backlight IC BKLT_SCL and BKLT_SDA both measure 0.545V diode mode to ground
I2C_BKLT_SCL and I2C_BKLT_SDA both measure... -
Hello, got an iPad Pro A2378 12.9 5th gen with no backlight. Got another test unit without screen, tested the screen, still no backlight with the test unit.
Figured out the backlight on the screen was bad, ordred a new backlight from mobilesentrix, *carefully replaced it* without damaging the lcd, oh well.
Final result, issue is still there, the screen has no back lights. So i'm back to square one, with 3 hours less and 100$ out, issue still on the screen.
The panel is still ok, i can see the apple in the middle of the screen when it kicks in, just no backlight.
Anyone... -
Hi all,
I've got an LG Flatron 24EN33TA with a backlight issue. The problem began with the monitor not powering up after sitting for a long time (overnight or during the day throughout work). When I would wake the computer up, the backlight would flick on for a second then go out. Sometimes it would take many tries to get it to come on. Once the monitor came on, it worked flawlessly until another long duration of being powered off.
I thought the problem would be bad caps but I checked both of the caps on the board and they are fine. I also tried powering the monitor from... -
this tv is throwing me for a loop. do samsung tvs no longer have the backlight self test feature built into the power supply?
i tested the backlight with my LED tester and it lights up both strips. one of them reads 100v and the other reads 63.7v.
unplugged mainboard from power supply but left backlight plugged in, and then plugged psu wall power in. expected to see backlights light up but see nothing.
according to how ive diagnosed in the past, this would almost always be a bad power supply. replacement power supply was cheap like 20$ from ebay. but still i get not even...
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