SMD Identification

Hi dougadam,

You said: The same type of component can be seen below the blown one

I'm not seeing it in the picture. Did you not get a wide enough angle on the camera shot?

Mike

It is the to the left at the bottom of the pic it as a 0 printed on it

Clive

My guess would be a capacitor. Check it with a multimeter. If it starts out looking like a short, and then the impedance changes, then it is a cap.

The component with a zero looks like a zero ohm resistor (no joke).

I suspect that the blown (hot) component was probably not another zero ohm resistor (jumper). If it was then an awful LOT of current flowed where it shouldn't have.

Hi

Thank you, they are zero ohm resistors apparently they are used as

links because of the SMD insertion machines in the PCB manufacture

we learn something new everyday. The cause of the short circuit was water in the

three way valve electronics because of a seal failure.

Thanks again

I must agree, they do look like zero ohm resistors, but I thought these were used to join 2 tracks on the circuit board together, when there there is another track in the way. But in this case there dosent seem to be any reason that the track could could not have a direct linked to the other side, hence then there would be no need for the 0 ohm resistor, it would also seem like a good idea to replace the zero ohm resistor with a sutible SMD fuse to protect the circuit board tracks, even though the zero ohm resistor seems to have done the job so far.

Hi

Yes i thought that myself, that there was no need to link out a track that did not

exsist but on further investigation of the board itself, it does seem that it can

be produced with different options and to choose these options they link out

different tracks. There is a example to the left of the blown resistor a gap with

solder pads. I am trying to find a SMD fuse but uptill now I cannot find any with

a rating of 240vac with a size of the resistor.

Thanks

The zero ohm resistor is smaller than the SMD fuse? try scratching back the insulation coating on the track and then fit the larger SMD fuse, otherwise bridge out the track and then fit a fuse somewhere else off the circuit board.

The good component is definitely a zero ohm 0805 or 0603 (can't tell the size in relation to other components) SMD resistor.

Are you 100% sure that the blown part is identical or are you assuming this because of the relative size?

To me the blown component looks like a capacitor (but could be a ferrite bead). If it is on a power rail to ground the value typically would be 100nF in either 0805 or 0603 size (again can't tell from the picture). They are certainly not rated at 240V though.

Hi

I can only say that the component is the same size but a good clue is there are

three relays on this control board controlling a three way motorised valve, a pump

and a heater all are 240vac with current ratings of 2A to 4A. Each relay output as

the same SMD component in it's common line. Like I said this would normally point

to a fuse protecting each controlling device. The phyiscal size is approx 5mm by 2mm

The three way valve was full of water which caused the short circuit

Thanks

Here I provide 250Vac / 125Vdc SMD 1810 fuse for your reference.

Its physical size is 4.5x2.5x1mm. Maybe it will be helpful to you!!