identify component: red-brown with white Q

[ghp]

Would someone tell me what the component is on the attached image? Red-brown color marked with white uppercase Q.

Thanks,

Gerard

[khaahk]

Re: identify component: red-brown with white Q

A fuse of some sort. Rating might come from schematic if mainboard platform can be identified.

[relax79]

Re: identify component: red-brown with white Q

Sorry for my poor English. This is "very fast acting fuse" Q is value of the fuse but I do not know exactly values and codes standart or not to all manifacturer. What is your motherboard model, you maybe find the schematic for identify to part exact code. In the attachment page 92 and 93 only example for you, they are not might be exactly your searching part.

[piernov]

Re: identify component: red-brown with white Q

We can see a 10mΩ resistor nearby, probably a current sensing resistor so the fuse might be at least rated for a few amps (3-10A ?).

[ghp]

Re: identify component: red-brown with white Q

The motherboard belongs to a Toshiba C855-P21, intel core I3 + amd gpu, the image attached is not mine but a lookalike. What is the symbol for a fuse on a schema?
Thank you all!

[relax79]

Re: identify component: red-brown with white Q

Your board is "PLF/PLR/CSF/CSR DSC MB" if I am not wrong.This motherboard not have exact schematic in net but in the attachment page 5 you see fuse6000 8,10,12A. I think your fuse value is 10A like in the SMD FUSE pdf page 93.

[ghp]

Re: identify component: red-brown with white Q

Sorry for my poor English. This is "very fast acting fuse" Q is value of the fuse but I do not know exactly values and codes standart or not to all manifacturer. What is your motherboard model, you maybe find the schematic for identify to part exact code. In the attachment page 92 and 93 only example for you, they are not might be exactly your searching part.

This is exactly what I was looking for: Q = 10A vfa fuse. Bingo.

[relax79]

Re: identify component: red-brown with white Q

What is your motherboards problem exactly?. If the fuse blow or open circuit then quite possible something big problem (strong short circuit power lines or supplys) happen in your motherboard. Fuses protect for when over current the own value.

[ghp]

Re: identify component: red-brown with white Q

What is your motherboards problem exactly?. If the fuse blow or open circuit then quite possible something big problem (strong short circuit power lines or supplys) happen in your motherboard. Fuses protect for when over current the own value.

My friend used a power supply with wrong polarity. I'd like to find what components have been damaged.

[relax79]

Re: identify component: red-brown with white Q

You must be check "PVADPTR" to GND and "PVBAT" to GND lines for short circuit or low ohm using multimeter before installing new fuse, if there is short then probably blow again your new fuse.If it is not short then probably work.

[ghp]

Re: identify component: red-brown with white Q

Couple of questions.

According to http://mayohardware.blogspot.be/2011...g-mosfets.html I should be reading between 100 and 500 on the mosfets with a diode test. That's OK for the F8707, but on the FDMC 8884 I read only 64. Moreover, it looks a lot as if gate and source are shorted on the 8884, as with https://www.badcaps.net/forum/showthread.php?t=41206.

Then I have a short to ground where I've drawn two connected red circles on the attached picture. I didn't expect this, but maybe it's normal?

I would have liked to determine that myself, using the schema earlier in this thread, but I cannot even locate the 2R2 resistor on that schema. Can someone point me in the right direction?

Thanks,

Gerard

[ghp]

Re: identify component: red-brown with white Q

I've removed the two components of which I'm sure they're toast.

Still hope someone (relax79?) will tell me if the short to ground is a problem.

[khaahk]

Re: identify component: red-brown with white Q

There should not be short to ground across the capacitor, from the picture it is hard to tell how the cap is connected in the circuit, one side of the cap must be on the ground...

[ghp]

Re: identify component: red-brown with white Q

There should not be short to ground across the capacitor

one side of the cap must be on the ground...

No "short to ground", but "on the ground": can you tell me what distinguishes the two?
On other Toshiba schemas I found plenty of these combinations: 2.2k resister - capacitor - ground.
Thanks, Gerard

[meritosari]

Re: identify component: red-brown with white Q

PLF/PLR/CSF/CSR DSC MB = Pegatron, schematic hard to find it on web. (you could try seek the boardview)

So we must use other schema as refer.

-AIC70
-VA70HW GDDR5


then we need to know AC_BAT_SYS have no short sircuits

Image HD1, HD2

Hope this helps

[ghp]

Re: identify component: red-brown with white Q

It sure helped, Meritosari, and the board is indeed a Pegatron, I found the code underneath the keyboard (where there was also an opening through which you could replace the fuse!).

It was enough to replace the FDMC8884 and the laptop was functioning again.

Thanks everyone!

[ghp]

Re: identify component: red-brown with white Q

II found the code underneath the keyboard

That was the code for the keyboard itself