Laptops forum


My laptop doesn't turn on, black screen, fan runs fast

by MuhammadFotouh / March 24, 2018 4:16 AM PDT

So my laptop is hp pavilion g7, it's been working for 6 years Today I took it apart to clean it, and put all together, and it's not working anymore! This is not the first time I clean it, I don't know what happened this time

When I boot it, the fan runs at maximum speed for as long as I keep it, the screen does not turn on at all I tried taking off the ram, the behavior was the same!!!

Check this video, nothing attached to the mother board, no ram, no hard drive, no cables, no links. Only the battery and power button, it runs like that, and it's absolutely no differece when I put every connection and every part in the mother board again

Please tell me what is that and what should I do.

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All Answers

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At 6 years
by R. Proffitt Forum moderator / March 24, 2018 6:18 AM PDT

It's likely to be the same old thing. Bad motherboard. Do try simple like a new CMOS battery. A buck part that for some reason folk overlook.

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A short explanation.
by R. Proffitt Forum moderator / March 24, 2018 8:08 AM PDT
In reply to: At 6 years

To avoid possible heat runaway conditions the fan circuit starts by default at max or near max fan speeds.

So when the motherboard fails to boot (not Windows, but the BIOS boot) then fans appear to be stuck on high. This is a GOOD THING since you don't want a thermal runaway situation.

But what CHEAP thing can cause many boards both in desktops and laptops to not boot? The CMOS battery. This is so CHEAP (again, it is cheaper than almost every other part and user serviceable) that we always pop in a new one since work beyond this gets expensive.

For some reason I'm reading folk push back on this CHEAP (hey, it is CHEAP so I'll emphasize it over and over) part for reasons I can't agree with. Sure there are ways to test this battery but the office and repair shop testing is costly. Just pop in the dollar part and test again.

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My laptop doesn't turn on, black screen, fan runs fast
by laptopmanindia / April 4, 2018 11:33 PM PDT

if your laptop is not working properly or screen up its required to formate.

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