Display has no backlight

My MBP has no backlight but has a display output. The LCD connector looks fine under a magnifying lens and so does the backlight fuse. I looked around and the backlight fuse is supposed to output 3 A 32 V. When I measured for continuity I got a beep, which is good. But when I measure the backlight fuse for voltage I get a reading of 0. When I measure amperage (assuming that's what A is) I also get 0. I feel like I'm missing something while testing. The logic board has everything unplugged including the battery connector; do I need the battery connector to be plugged in?

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4 Commenti:

With it put back together and you shine a flash light though the Apple Logo are you able to see the faint image of your desktop icon's?

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@bluesywalnut the fuse does not have an output, it is not supposed to put anything out. . How did you measure the voltage (no reason to measure the amperage at all) at the fuse?

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@oldturkey03 I put the multimeter probes on the ends of the fuse. I didn't know it's not supposed to output anything. I read on a forum that it was a 3 A 32 V fuse, so I assumed it was supposed to output 32 volts.

da

Nope. With the power on put the black probe of your meter on ground and the red on either end of the fuse. That would give you the power going through the fuse(circuit) with a maximum of 32V for that fuse.

With no power on the system you can only check for continuity of your fuse by placing the meter in ohm's (depending on your meter some beep for continuity)and you should see resistance if the fuse is intact. If it is not then your meter will not show anything.

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