0
\$\begingroup\$

Could someone please help me identify what this component is? This is from an HP laptop motherboard (FPP55 LA-G07JP)

enter image description here

marking on the component are:

4R7  
918  
013  

Marking on the PCB calls it PLB1, but there are other similar looking components on the board are marked as PLZ1, PLZ2 and PLZ3 (those three have identical numbers on top, R24 919 196, but physically look same as the component pictured below).

Some components next to the thing are fried (probably capacitors). I actually need to find the values for the fried ones but I can't find schematics for this board, so I'm trying to find some information about the components surrounding it. What is the circled component?

EDIT: Some more detailed pictures
1.
enter image description here
2.
enter image description here
3.
enter image description here
4.
enter image description here
5.
enter image description here
6.
enter image description here
7.
enter image description here
8.
enter image description here

\$\endgroup\$
4
  • \$\begingroup\$ Overall this area hints of being part of a switch regulator, though I can't see one on the picture. It could also be some simple filter on the input. You have to rule out that no traces were fried along with those caps. Generally when a regulator blows (if that's what has happened), you replace the regulator IC and all surrounding diodes and MOSFET. The coil doesn't typically get damaged. \$\endgroup\$
    – Lundin
    Oct 18, 2021 at 8:46
  • \$\begingroup\$ @Ludin I can get better quality zoomed out pictures of the board if this is something worth looking into, but with just a general scan of the area near the inductor I can't find anything that might be a regulator IC. The 3 pin component at the upper part of the picture above has 50Q19 on it, but I can't find out what that it. At the very least it don't look like something common. And I'm also guessing the square component to the top left is also not a regulator. Other than these, most components nearby the inductor are just capacitors and resistors, as far as I can tell \$\endgroup\$
    – user13267
    Oct 18, 2021 at 9:39
  • \$\begingroup\$ A more zoomed out picture is probably more helpful, to understand what these components are actually for. If it's a regulator it is very likely placed close to the coil. It could in theory be placed on the opposite side of the PCB, though that's a bad regulator layout. There's also a very low (0.01ohm) resistor placed in series or across the coil, which is very likely a current sense circuit. \$\endgroup\$
    – Lundin
    Oct 18, 2021 at 9:47
  • \$\begingroup\$ @Ludin added some more pictures of the board nearby the damaged components \$\endgroup\$
    – user13267
    Oct 18, 2021 at 10:11

2 Answers 2

1
\$\begingroup\$

It is an inductor (coil/choke). The inductance is \$4.7 \mu H\$.

And in real life, it is very hard to break the inductor. I'm sure the inductor of fine. The ohmmeter should show a short circuit (low resistance).

\$\endgroup\$
4
  • \$\begingroup\$ I pulled out the charred pieces. The laptop wasn't turning on before but it is now. If I connect the laptop charger this component starts getting hot. The other similar components on the board also get a bit hot but not as much as this one. I can't find out what the charred components are or their values. Do you think it would be safe to use this? Windows also shows the battery charging, and from outside everything looks normal. Only reason I can tell it is getting hot is because I am operating the laptop without it's cover and directly touching it \$\endgroup\$
    – user13267
    Oct 16, 2021 at 14:40
  • \$\begingroup\$ Did you desolder the broken capacitors? And clean the PCB? Next check for a short circuit and try to look and check (near the inductor) the IC (MOSFET - eg. AON7408) or charging controller. \$\endgroup\$
    – G36
    Oct 16, 2021 at 15:34
  • \$\begingroup\$ actually the burned components broke off when I wiggled them with a tweezer. I've cleaned the burned part using a dry air blower. It looks like some parts of the PCB copper have been ripped off and a hole has burned through the PCB itself near the inductor (the black part inside the red circle above). I don't know if this is still repairable but don't want to give up on the laptop either because other than the inductor heating up, it seems to be working fine. It doesn't heat up (as much) if the laptop is turned on through battery, it heats up only when the charger is connected. \$\endgroup\$
    – user13267
    Oct 16, 2021 at 16:31
  • \$\begingroup\$ @user13267 The parts burnt because of a current rush. They aren't the cause but a symptom. You have a short somewhere, or the input voltage is bad etc. The caps are very likely just decoupling ones towards ground. It rather looks like high current has passed through the trace where one side of the caps were connected. No, it isn't safe to use this before you find the actual cause of the problem. \$\endgroup\$
    – Lundin
    Oct 18, 2021 at 8:49
0
\$\begingroup\$

That's a 4.7 uH inductor in the picture.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.