I have the circuit in the photo attatched and I beieve the component marked is burnt, but don't know what it is. In this case the circuit is used to ilght up the LED's on the back when feeded with a power source between 7.4 nd 12.8 Volts.
Does anyone have a clue on what it could be?
Thank you. I really didn't know this existe. Now I am shure it burned out. So, if I understood it right, the zero-ohm link is used as a fuse? Or is it just a jumper?
It is going to be difficult to burn a zero Ohm resistor. Why do you think it is burnt? If it is burnt, then the other components are likely to be damaged as well.
Do tell us for starters, the purpose of the module in question, where it is used, from where did you get it and so on?
Zero ohm resistors have various uses, typically as jumpers or to allow the same PCB to be populated in several ways for circuit variations, perhaps in a filter network. Sometimes they are used to allow prototypes to have current shunts that allow each chip's current consumption to be monitored (not needed in production). They also function as zero inductors. A zero capacitor is an unpopulated capacitor of course!
krupski:
That's a zero ohm resistor (i.e. a jumper). And to the OP: it's not burned.
I never suggested otherwise.
What it is doing there is certainly unclear as it is obviously a double sided board and so a jumper as such should not be needed.
There are however two other resistors whose value I cannot quite discern, which would be entirely consistent with it implementing a constant-current driver.
17 mOhms looks like quite high value for 0R. Are you sure you did not measure contact resistance instead? This is comparable to good MOSFETs. But it is true I have never bothered measure it.