Electronics > Repair
Console repair: Help identifying components
(1/3) > >>
newtekuser:
Have a portable gaming console than doesn't power up (power LED stays red when charging and only blinks red once when pushing the power button), upon disassembling it I see what appears to be a blown 0603 component. From what I can tell, it is part of a power regulation circuit.
It doesn't appear to be a diode because when I measure the other two identical components next to it there's no voltage flowing through them. None of the components in this area are shorted to ground and when I measure the other two identical components similar to the burnt black one I get about 0.40 ohm. This tells me this may be a current sense resistor.
I'm guessing this component was blown by the in-rush current from the wifi chip which is in the biggest component in the area. I also don't see any diodes around which is very weird.

As part of the same power regulation circuit I also see three mosfets marked "AHRP 590" but a Google search doesn't reveal anything of use about them. I'd like to see if any were taken down with the blown component if I can find any data sheets for them.

In the two pictures you can see the board before and after cleaning.

Can someone confirm if this is indeed a current sense resistor?
What about the mosfet?
fzabkar:
The manufacturer of AHRP is Monolithic Power.

Edit:

MP8765GQ, Monolithic Power, 24V, 6A High Efficiency Synchronous Step-down Converter with Hiccup OCP, PWM/PFM mode pin and output discharge, marking AHRX+XXX, QFN3x3-16P:

https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP8765/

http://markingcodes.com/search/c/ahr


Edit #2:

Could the "current sense resistor" be a ferrite bead?
newtekuser:

--- Quote from: fzabkar on July 12, 2024, 06:25:03 pm ---The manufacturer of AHRP is Monolithic Power.

Edit:

MP8765GQ, Monolithic Power, 24V, 6A High Efficiency Synchronous Step-down Converter with Hiccup OCP, PWM/PFM mode pin and output discharge, marking AHRX+XXX, QFN3x3-16P:

https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP8765/

http://markingcodes.com/search/c/ahr


Edit #2:

Could the "current sense resistor" be a ferrite bead?

--- End quote ---

Thank you for the link! I went with my gut feeling and ordered some current sense resistors since I could not find ferrite beads of the same resistance. I also ordered a few of the MP8765 buck converter ICs just in case since they're cheap.
fzabkar:
I would make sure that the load side of the DC-DC converter is not shorted or overloaded.
wraper:
Blown component is a ferrite bead. Exact value not important, what matters the most is if it can handle enough current. FWIW you can replace it with a jumper and circuit will work just fine. Although I doubt it blew by itself, something else should have failed and caused a very large current flow. You should check if either side of the ferrite bead is shorted to GND.
Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod