Function of the fuse F4

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screwdriver
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Function of the fuse F4

#1 Post by screwdriver » Fri May 16, 2008 2:55 pm

hello,
I've measured a few fuses on my mainboard (T41) because it reports fan error. on the left lower corner (front side) where usually the white sticker is the tiny fuse F4 seems not to work.
does anybody know about its exact function?

thank you

richk
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#2 Post by richk » Fri May 16, 2008 8:16 pm

I'm out of town and don't have a board to look at, but I would try to measure the resistance between one side or the other and the positive connector on the fan socket. I guess I would try to get a similar board (dead) and pull off the fuse and solder it in. If you cannot find one, I can send you one next week for the postage.

screwdriver
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#3 Post by screwdriver » Sat May 17, 2008 5:16 am

hello and thank you for your awnser.
the resistance is (in the range if my multimeter) not measurable. all other fuses are about 0.5~0.6 ohm, this seems not to conduct (resistance infinite...).
how do you mean measure between the positive connector of the fan socket?

Harryc
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#4 Post by Harryc » Sat May 17, 2008 5:26 am

Why over analyze it. Just solder on a temporary jumper to bypass the fuse and see if it fixes your problem. If it does do a proper repair. If it doesn't, try a fan. If the fan actually blows the fuse then you need to do both.

screwdriver
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#5 Post by screwdriver » Sat May 17, 2008 11:03 am

that's a good idea but I'm scared of thrashing the board totally...

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#6 Post by richk » Sat May 17, 2008 2:57 pm

I would only try a jumper if I had a known-good fan. If the fan moter is shorted causing the blown fuse, I would hate to trash the MB. If I had another good fan, I would try shorting it (if I didn't have a fuse) as a TEMPORARY repair, because if there is something else wrong in the fan circuitry, I would be unlikely to be able to fix it.

screwdriver
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#7 Post by screwdriver » Sun May 18, 2008 7:41 am

I've bridged the fuse and voila: the board is running. thanks for your help @ all!
I'm searching for a new fuse now, then everyhting should be fine again.

Harryc
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#8 Post by Harryc » Sun May 18, 2008 8:23 am

If you could take a picture of the fuse location as you replace it and post it here, that would be helpful to others. Thank-you.

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#9 Post by richk » Sun May 18, 2008 10:00 am

A fuse doesn't blow for no reason. I would certainly change the fan.

screwdriver
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#10 Post by screwdriver » Sun May 18, 2008 1:21 pm

I'm not pretty sure why the fuse blew but I have 100% working fans to test.

http://img143.imageshack.us/img143/275/ ... gf4ci5.jpg

Harryc
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#11 Post by Harryc » Sun May 18, 2008 1:37 pm

Nice pic, thanks.

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