Author Topic: Backlight Tester.  (Read 614 times)

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Turnip

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Backlight Tester.
« on: March 16, 2017,11:50:42 »
Hi folks,

Got one recently, only 16.00 inc post. User guide was in Chinese, so thought check it out.

Noticed little in the way of Mains isolation, but guess not a problem.

Seems it does everything required, also has a nifty insulation tester that bleeps 'Leak' when using an Avo 8 on the 300 volt range, even when set on a pretty low output - Guess some sensitivity - Chris.

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Backlight Tester.
« on: March 16, 2017,11:50:42 »

vinceroger69

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Re: Backlight Tester.
« Reply #1 on: March 16, 2017,15:56:12 »
how easy is this too use? does the voltage go up automaticaly or do you adjust it yourself also if strip has a shorted led i guess it will show up on the amps meter?

downunder

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Re: Backlight Tester.
« Reply #2 on: March 17, 2017,03:08:37 »

Piece of cake. Just connect the probes across the + and - terminals of the strip. It automatically increases the volts until the strip lights up and stops there. Don't know about current but it doesn't appear to be a problem. Details are scant and all in Chinese. Love the pointy probes on it. Must-have tool these days.                           Bruce

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Re: Backlight Tester.
« Reply #2 on: March 17, 2017,03:08:37 »

vinceroger69

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Re: Backlight Tester.
« Reply #3 on: March 17, 2017,05:23:34 »

Piece of cake. Just connect the probes across the + and - terminals of the strip. It automatically increases the volts until the strip lights up and stops there. Don't know about current but it doesn't appear to be a problem. Details are scant and all in Chinese. Love the pointy probes on it. Must-have tool these days.                           Bruce

I might order one of these then saves stripping the panel down each ime to test the leds some leds i see are failing oc some sc
ive read if a led fails short circuit it can still light up? hence asking about the amp meter if one or more is short circuit i guess it will  draw more amps? (im still learning electronics so bear with me)

Turnip

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Re: Backlight Tester.
« Reply #4 on: March 17, 2017,12:49:12 »
Hi Bruce and Vince,

Also impressed by those pointy probes.

Checked max current on the four settings - They were as noted, so guess no problem with a S/C Led.

Found indicated voltages and current pretty well spot on with my Avo.

Think also the leak test useful as suspect it's in a multi megohm range, where most any leak after a burn-up would cause a constant bleep, and the set might well sense it and cut the supply.

zomikula

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Re: Backlight Tester.
« Reply #5 on: March 19, 2017,08:33:41 »
Got one of these last year
Saves alot of time to be honest.


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Re: Backlight Tester.
« Reply #5 on: March 19, 2017,08:33:41 »

vinceroger69

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Re: Backlight Tester.
« Reply #6 on: April 01, 2017,12:15:56 »
Hi folks,

Got one recently, only 16.00 inc post. User guide was in Chinese, so thought check it out.

Noticed little in the way of Mains isolation, but guess not a problem.

Seems it does everything required, also has a nifty insulation tester that bleeps 'Leak' when using an Avo 8 on the 300 volt range, even when set on a pretty low output - Guess some sensitivity - Chris.

with this tester do you have to alter the voltage manually? to left knob or do these increase the voltage slowly like a soft start and ramp the voltage up slowly and what is the switch for below the knob?

Turnip

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Re: Backlight Tester.
« Reply #7 on: April 01, 2017,12:35:37 »
Hi Vince,

4 position switch is for max current (as noted)  Potentiometer controls voltage from 7.5v to max but as limited by max current, seems no chance of damaging Leds.

Seems OK so far - Don't know how it compares with the more expensive version, but it shows current also a leak test at a fairly high voltage as strips can well burn a bit -  Haven't yet checked how many megohms it can suss at near 200v - But guess a useful option - Chris.

vinceroger69

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Re: Backlight Tester.
« Reply #8 on: April 01, 2017,13:18:35 »
Hi Vince,

4 position switch is for max current (as noted)  Potentiometer controls voltage from 7.5v to max but as limited by max current, seems no chance of damaging Leds.

Seems OK so far - Don't know how it compares with the more expensive version, but it shows current also a leak test at a fairly high voltage as strips can well burn a bit -  Haven't yet checked how many megohms it can suss at near 200v - But guess a useful option - Chris.
im in two minds the one you have or this one goes up too 300v
https://www.hklrf.com/0-300V-Smart-Fit-Voltage-All-Size-LED-LCD-TV-Laptop-Backlight-Tester-Tool-Lamp-Beads-Test-Detect-Repair_1948.html
its just under 22.00 delivered to the uk

Turnip

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Re: Backlight Tester.
« Reply #9 on: April 02, 2017,12:59:10 »
Hi Vince,

That was the other option I referred to, but as I haven't bought one, can't give an opinion.

Mind you, your preference suggests good mains isolation, where the cheaper one might be suspect as noticed no transformer inside when I lengthened the supplied short mains lead to reach the power socket.

Guess they both do much the same thing - The cheapy has a leakage check which could be useful in the case of a string burnup - But there again, it should be obvious - Chris.


vinceroger69

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Re: Backlight Tester.
« Reply #10 on: April 02, 2017,14:31:45 »
Hi Vince,

That was the other option I referred to, but as I haven't bought one, can't give an opinion.

Mind you, your preference suggests good mains isolation, where the cheaper one might be suspect as noticed no transformer inside when I lengthened the supplied short mains lead to reach the power socket.

Guess they both do much the same thing - The cheapy has a leakage check which could be useful in the case of a string burnup - But there again, it should be obvious - Chris.
Thanks for your reply in the end i went for the one that i linked above and have also ordered some of the replacement leds that tv tony recommended so i need to find some more tv projects too work on now whilst im waiting (only do this as a hobby for family/friends).

 

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