Need help understanding MSI schematic component

[arrow_runner]

I'm currently trying to repair my late brother's MSI laptop. He bought it broken off eBay with no LCD display, and he used it as a desktop. I'm hoping to fix it to use it for tuning the car my dad and I are building with the engine I got from my brother before he passed.

I bought a new LCD since the old one is gone. I've since found that whoever had the laptop before had broken a resistor by the ELP connector when they put in a new battery.

I need assistance deciphering the schematic to order the appropriate resistor. The resistor is marked 1R2 which I understand to be a 1.2ohm resistor. However I do not know the wattage, for however much that matters.

The motherboard is a MS-16R31 and I found the schematic here:

https://www.badcaps.net/forum/showthread.php?t=95332

This is the resistor that needs replaced. I would like to understand how to read this please. Thank you in advance.

PL19
X_CH-1.2u7A41mS
L04-12A7570-M26
CHK_S2_P3_55

[mon2]

Re: Need help understanding MSI schematic component

Sorry to hear about your brother. Welcome to the forum.

Sounds like a fun project.

The referenced part is PL19 and such prefixed parts are coils or inductors. If the part was Rxx, then the part is a resistor.

PL19 is used with the switching power rail created by PU19. Specifically, it is a buck regulator. A buck regulator will take a higher voltage and drop it to a lower voltage. The right side of this portion of the schematic notes the peak current demanded by this power rail.

This peak current is important to select the proper replacement inductor. Also important is the physical size and shape for the PCB pads to align.

This part is 1.2uH ('micro Henries'). Any inductor that can exceed the peak current is fine.

A switching power supply will turn on and off to dial down the input voltage to power the target component.

Post a pic of the pcb that can show the pads of this missing inductor. If possible, try to measure the distance between the 2 pads for this missing inductor.

There are many parts that can replace this one. Available from Digikey or Mouser, etc.

[arrow_runner]

Re: Need help understanding MSI schematic component

Thank you so much for the clarification!!!

I found this on digikey. The dimensions look spot on for the board though it's bigger than the broken inductor. It's 1.2 uh & rated for 8.7 amps. Look good to you?

[mon2]

Re: Need help understanding MSI schematic component

The electrical specs look great. Better than the original. This will run cooler than the original. The concern is with the physical body size.

Best to search a bit to find the best fit. Ideally you want the same fit.

Review each datasheet for the part. The datasheet will offer the body dimensions and the pcb pad recommendations. These should match your pcb as close as possible.

Post the link when you believe you have a solution for a quick review.

[arrow_runner]

Re: Need help understanding MSI schematic component

I've been looking through the datasheets and I think this is just a compromise I'll have to try. Anything with 1.2 uh & 7 or greater amps either has pads too small and close together or is even bigger than the one I found.

[mon2]

Re: Need help understanding MSI schematic component

Ok - back @ home now.

Wait..you have the inductor already. You wish to replace it? Any reason why? It is rare for such inductors to be defective.

Can you post a bottom side view of the 1R2 inductor you show in the earlier pics?

The part looks to be ok and just needs to be soldered back onto the PCB. Use flux and enough heat to melt the solder that is present on the PCB pads.

[arrow_runner]

Re: Need help understanding MSI schematic component

The original inductor was broken off by the pads. As in they're still soldered to the motherboard and no longer attached to the inductor.

[mon2]

Re: Need help understanding MSI schematic component

The part you have found looks like a winner to me.

You should be fine to use this on the same PCB pads you measured on the logic board.

Purchase a spare - just in case. If required, some flux which will help to flow the solder onto the pads.

You can use standard leaded (aka low temp) solder wire here to solder it back on.

Do review your board for other possible parts you may require. Often they are also available from DK.

[arrow_runner]

Re: Need help understanding MSI schematic component

Thank you so much for your time helping me with this. I've got the parts ordered. I've compared pics of my board with some I found online and this seems to be the only 'missing' component.

There is a capacitor by the EDP connector that has it's pads partially lifted from the board, though everything seems electrically connected still. Once I get done with the solder work and testing I'm going to put a little silicone over the cap to hold it in place.

[arrow_runner]

Re: Need help understanding MSI schematic component

Success!! Thank you so much!!

[mon2]

Re: Need help understanding MSI schematic component

Good job!! Will drop off some boards to repair the next time we go to Cedar Point

[arrow_runner]

Re: Need help understanding MSI schematic component

Haha. Tell you what if you're ever coming through the area I'll take you for a ride.

[rediii]

Re: Need help understanding MSI schematic component

Haha. Tell you what if you're ever coming through the area I'll take you for a ride.

wow, that looks great

[ibo]

Re: Need help understanding MSI schematic component

WOW nice one!!

[fgtfv567]

Re: Need help understanding MSI schematic component

I have the same board and ended up having the same problem! PL19 inductor is ripped off and the legs are still soldered to the board! Thanks for the info guys and for finding the inductor for me!

[fgtfv567]

Re: Need help understanding MSI schematic component

The part you have found looks like a winner to me.

You should be fine to use this on the same PCB pads you measured on the logic board.

Purchase a spare - just in case. If required, some flux which will help to flow the solder onto the pads.

You can use standard leaded (aka low temp) solder wire here to solder it back on.

Do review your board for other possible parts you may require. Often they are also available from DK.

I bought the same inductor that was linked in the thread. PU19 let out the magic smoke and will ignite when I turn on the laptop on now.

Pin 3 for the SW that connects to the Pl19 inductor now directly connects to GND. As far as I can tell the legs of the buck converter did not touch and it must have shorted inside the chip.

How did this happen? How do I prevent this from happening again?

[TuxTaunk]

Re: Need help understanding MSI schematic component

Success!! Thank you so much!!

hi! can you tell me where you bought the replacement? sorry my english