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Electronics => Repair => Topic started by: EVGAdrifter on November 12, 2018, 11:09:35 pm

Title: Help me identify fuse location
Post by: EVGAdrifter on November 12, 2018, 11:09:35 pm
Could some help me identify the location of fuse F3 and F7? the layout of the text on the PCB isn't helping. Long story short i am trying to find the backlight fuse on lenovo x1 carbon 3rd gen laptop, I believe its either fuse F3 or F7.
(https://i.imgur.com/gtzXwEj.jpg)
Title: Re: Help me identify fuse location
Post by: ataradov on November 12, 2018, 11:18:49 pm
I'm thinking those components with two white lines parallel to the capacitors (positioned vertically).
Title: Re: Help me identify fuse location
Post by: coromonadalix on November 13, 2018, 12:24:08 am
not sure but the black dot  under the F3 F7 writings, you have 2 unpopulated pads and he's placed under them, you have an rather large pcb trace going to it ?
Title: Re: Help me identify fuse location
Post by: ArthurDent on November 13, 2018, 01:31:41 am
Capacitors are generally beige or greyish and resistors are generally black. Fuses generally have a white ceramic body color. I can't tell from the photo but what is the device right above the 'D' in 'D63'? Could we see more of the board? It's hard to tell what the white thing in the upper left near the red and black wires is. The component above D63 seems a little small for a fuse.
Title: Re: Help me identify fuse location
Post by: coromonadalix on November 13, 2018, 02:08:00 am
or maybe the two near the q33 markings ?  normally smt fuses are easily spottable, can you do an zoomed out photo ?
Title: Re: Help me identify fuse location
Post by: JFJ on November 13, 2018, 11:56:00 am
On the 2nd generation version of your laptop, the F3 fuse is more clearly marked:

(https://www.eevblog.com/forum/repair/help-me-identify-fuse-location/?action=dlattach;attach=570578)

Its marking is two white stripes - the same as in your picture:

(https://www.eevblog.com/forum/repair/help-me-identify-fuse-location/?action=dlattach;attach=570584)
Title: Re: Help me identify fuse location
Post by: drussell on November 13, 2018, 12:56:54 pm
My first thought was the same as what JFJ marked up in the posted graphic:

Quote from: JFJ on November 13, 2018, 11:56:00 am
(https://www.eevblog.com/forum/repair/help-me-identify-fuse-location/?action=dlattach;attach=570584)

.. since everything else in the area that are whitish looks like they're all similar looking capacitors.  The two marked components are the only things in the vicinity that look a bit different.
Title: Re: Help me identify fuse location
Post by: coromonadalix on November 13, 2018, 09:29:39 pm
wow  never saw thoses kind of fuses, im learning,    are they good or open ??
Title: Re: Help me identify fuse location
Post by: tehmagicsmoke on November 14, 2018, 06:52:05 pm
Test those components with the white marks for 0 ohms. That'll confirm it.
Title: Re: Help me identify fuse location
Post by: ArthurDent on November 14, 2018, 09:08:33 pm
Do I get a prize for being the first one with the right answer?  ;D
Title: Re: Help me identify fuse location
Post by: Ice-Tea on November 14, 2018, 10:09:52 pm
Perfect illustration of my credo: if you can't manage to put clear and unambiguous ref designators on your silk screen: don't bother.

Piss poor job.