Elusive resistor 0.24 ohm

[konrad]

Hi,

 

Don't know if this is the correct place to ask my question but it seems the most logical looking at the options available. I have been writing and receiving feedback on an issue relating to an Acer monitor that I am trying to repair. The few components I have managed to test with my multi meter have all checked out OK but for one resistor on the power pcb. This particular resistor has a value of just 0.24 ohms according to the colour coding on it. It is reading 0.7 ohms. As the resistor has a tolerance of just 5% plus or minus I would judge that it is faulty and needs replacing.

This is where I need your help. Trying to source a resistor with this value is proving almost impossible. I have found them for sale but in bulk orders only (50+). Does anybody know where I can get hold of a 0.24 ohm resistor (just one)?

 

regards,

 

Konrad :confused:

[Vr5fx]

Try here.

 

http://uk.farnell.com/vishay-bc-components/ac03000002407jac00/resistor-0-24r-3w-5-wirewound/dp/1838956?Ntt=0.24+ohm+resistor

 

Not sure if this is what your looking for.

 

-Vr

[Synapse]

I'd check the accuracy of the measurement range before splashing out.

 

I've just looked at a Fluke meter as an example, 0 - 600 ohm minimum range, accuracy 5%, which is often 5% of range.

 

That would be 30 ohms, and so wouldn't be able to accurately measure your 0.24 ohms.

[Plastic Nev]

I agree with Synapse here, as well as the possibility of meter errors at such a low value, I actually am questioning the value shown any way, a photo of the resistor would be nice, but the colours on it will do, I must also ask, are you testing this resistor with at least one end un-soldered from the circuit board? and also in both directions, I have seen diodes with coloured bands on them. If a diode it will conduct one way, but not the other.

I work with electronics on machine control circuitry, and as a licensed radio amateur, I have built audio amplifiers and radio transceivers, as well as repaired them, and never yet come across a resistor of such a low value, hence why I think you may have something wrong.

 

However, if in fact this is the correct value at 0.24 ohms, a length of wire, say a foot of thin wire from a redundant bit of telephone wire, soldered in in place of that resistor, then try the circuit.

0.24 ohms is such a small value it is near to a full circuit any way, so a length of thin wire will be near enough as good a replacement for test purposes.

 

 

 

Nev.

[konrad]

Thanks for your input. The resistor has been removed completely from the pcb and the colours are red/yellow/silver/gold. The silver is just that as it shines whereas grey is a matt colour. Grey would give a reading of mega ohms. I have tried to photograph the resistor but the macro is struggling to pick up the focus and colour. I did test it in both directions although this should not make any difference to a resistor and this is undoubtedly a resistor. The only possible explanation is that the silver turns out to be grey but I have seen grey on other risistors and it looks nothing like the silver colour on this resistor. The meter is what it is and I don't have the resource to guage its accuracy so I have to believe what it is telling me.

 

regards,

 

Konrad

[KenB]

How about this?

 

click here

 

USA - sorry but they must be available.

[Plastic Nev]

Hum, I am surprised, as the colours are correct. Without knowing the circuit, and doubt there is any circuit diagram available, I do wonder at its purpose except as some sort of current limiting resistor. As I said, that low a resistance is nearly a short circuit anyway so if your meter is showing it to be still below 1 ohm at 0.7 which granted is nearly three times higher, I doubt that this resistor is the reason for the full circuit failure. Maybe get a dimmer monitor screen because of it, but not full failure.

However if you can obtain a replacement cheaply enough, then go for it, it won't cause harm replacing it, though do be ready for disappointment if the monitor still doesn't work.

 

Nev.