2009 MPB pro no lights on mag safe

[stonewall]

2009 macbook pro 15"

Could someone tell me if this is the power fuse?
I've put my ohm meter across this and there is
no continuity. Should there be? If this is a fuse
does anyone know what part number I would use
to replace it?

Picture is attached below. Thanks.

story:
water damaged, won't boot, completely dead,
no green or orange light on magsafe charger

I'm looking for some help finding the first thing
to check, supposedly there are surface mount fuses
somewhere on the logic board. It would be great if
someone could point the first one out to me.

I have beed using a disconnected keyboard and
a thunderbolt to hdmi for the monitor, and of course
a magsafe charger. Sort of a test setup.

I've used this on a second, working logic board to
make sure this actually works.

So, I'm down to the logic board. And this is new territory
for me.

Thanks in advance.

[stonewall]

Re: 2009 MPB pro no lights on mag safe

Okay, I think I've found the schematic.
Looks like 6A - 24v --- now I still have no
idea how to find this, like say on digi-key,
I need some type of part number. I'm
not to familiar with what this package is
or what I need in a surface mount component.

I'm referring to schem1 attachment below.
Thanks.

BTW, I was using my meter to check other things
that I was guessing were fuses. Can an ohm meter,
on ohm meter setting, blow these fuses?

[kc8adu]

Re: 2009 MPB pro no lights on mag safe

that looks like a mlcc not a fuse.

[trebo]

Re: 2009 MPB pro no lights on mag safe

I agree with kc8
some fuses look like that but usually have a letter printed on them to give you a amp value (not that colour thou)

[stonewall]

Re: 2009 MPB pro no lights on mag safe

I'm not sure what a micc is,
but my picture is of a capacitor.

I found the fuses and they both have
continuity.

I'm not sure what to check next.

Thanks.

[stonewall]

Re: 2009 MPB pro no lights on mag safe

So, these are the two objects that I believe to be the power fuses.
I checked each one with my ohm meter, and they both have
continuity.

I guess I would first like to know why my magsafe lights
do not come on, either the green or the orange. It looks like
it's not getting any power. So any landmarks to check
would be very helpful.

I have already checked the DC IN board to be OK.

Looks like there's not much interest in this,
thanks for any hints. I probably wouldn't be
able to fix it anyway.

I sprayed the board down with contact cleaner,
and then air hosed it off. It's still kind of dirty
and I'm going to scrub it down with alcohol now.

[khaahk]

Re: 2009 MPB pro no lights on mag safe

Look like this ic has been damaged already by liquid. Some of contacts have been destroyed. Might be charger ic, hard to tell from the picture. Take magnification glass and look closely.

[stonewall]

Re: 2009 MPB pro no lights on mag safe

Thanks for your response. I will take some better pictures,
after I do some cleaning. (next week)

I have a schematic, but I cannot tell where anything
is on the circuit board.

I think the first step is to get lights on my magsafe
working, indicating power is getting through. Does
all this start with the charger IC ?

Does this charger IC send the sense line to
the DC IN board?

I can't sleep, so I took a picture. I cleaned
up the IC discussed. And I put power on and
measured vDC of 24.2 on both sides of the
white fuse, reference the blue lines. So I think
the fuse is good, if that's a fuse.

[dj_ricoh]

Re: 2009 MPB pro no lights on mag safe

thats not a fuse. not even a cap maybe coil.
if that was on a normal notebook it will have a mark like L or PL

[trebo]

Re: 2009 MPB pro no lights on mag safe

is that a burnt hole in the top left of that IC ???
just under the L of the bottom lettering

[stonewall]

Re: 2009 MPB pro no lights on mag safe

That's not a hole, it doesn't go down.
It looks like a reference dot. But it's
hard to tell with only a magnifying glass.

I'm going to look for a microscope so
I can clearly see if there are any bridged pins
or rusted off pins, or whatever.

I just don't know what's what yet.

I have identified the fuse for the LCD
display, it's a much smaller package than
the white things, and it has a dot. I haven't found
anything with an L or PL.

I measured the voltage on both sides of the white
things, and it was the same. That's why I think it's
a fuse. But I really don't know.

[khaahk]

Re: 2009 MPB pro no lights on mag safe

Follow the planes, where the white "thing" comes and goes.
If it starts from adapter + and goes to some sop8 mosfet, then it is most probably fuse on + side.
If it comes from the adapter - side and ends in mainboard GND planes then it is also fuse.
If it stands in parallel, then it is cap.
At the end of the white "thing" there are 7 vias through the plate to the othe side. Where does it go from there?

By the way on the othe picture the ic looks rather good, so not sure about earlier statement.

[stonewall]

Re: 2009 MPB pro no lights on mag safe

I'm adding 2 more pictures.

Following the traces from my hypothetical fuse
there is really nothing on the other side of the board
but a series of vias that do not have traces on
the visible back side. pic F_1

The other picture of the VM97 chip, is a
L8543SQ WLED backlight chip. I'm not sure if
this is just for the backlight or if
it's also for the display.

Anyway.

[khaahk]

Re: 2009 MPB pro no lights on mag safe

The 8543 looks ok. Do you have a working battery? Does it turn on with battery only?
If it works on battery, then there is max9940 overvoltage protection chip.
Next you have to find charger ic and see if it gets power.
If it does not work with battery either, then standby voltages, ec voltage ...
If you have schematcs, post it...