Acer D150 resistor replacement

[spleenharvester]

Hey all. Got a motherboard here with a faulty 4407A MOSFET (to be replaced by a 4407 shortly) and a blown SMD resistor.

The resistor is marked on the schematic as being 0.05ohm, 1206 size, 1% tolerance.

I cannot find a single 0.06ohm resistor in 1206 size on any of my scrap boards. I've found a few "0ohm" 1206 1% resistors but no 0.06ohm.

What possible values can I replace it with?

Cheers!

EDIT: Forgot to mention the most important part haha. It's right on the VIN line, check: http://i.imgur.com/g9wfRDF.png It's PR56.

[spintop]

Re: Acer D150 resistor replacement

0 ohm is fine too.

[spleenharvester]

Re: Acer D150 resistor replacement

Think I'll just use that then. What even is the point of a 50mOhm resistor in a circuit like this, just out of curiosity? Will 0ohm last long term?

Cheers!

EDIT: https://en.wikipedia.org/wiki/Zero-ohm_link

You learn something new every day haha. Hopefully it worked if it's there as a low-cost fuse, since I can't see anything blown beyond that point.

Cheers!

[whaldsz]

Re: Acer D150 resistor replacement

Think I'll just use that then. What even is the point of a 50mOhm resistor in a circuit like this, just out of curiosity? Will 0ohm last long term?

Cheers!

You get R = 0.05 ohms or 50 milliOhms, Voltage drop across this R is say 0.5V or 50mV. What would be the current flowing through it?

I = V/R = 0.5/.05 = 10 Amperes.

In charger circuit (ISL6251 for example), it is used to regulate AC adapter current (CSIP/CSIN pins) together with the ICM pin.

[spleenharvester]

Re: Acer D150 resistor replacement

Update on this board, replaced the MOSFET and resistor, still no go. Completely dead, shorts reading all over the place. A lot of the crap connectors on this board melted as soon as I brought the heat gun near so I'm going to stick it in the scrap pile.