No power to board

dc42

Is there any sign of damage to the small square chip labelled U3? It's close to that 5V internal enable jumper.

Stormdrewper

@dc42 No there doesn't seem to be any damage to the u3 chip or anything around it.

dc42

@Stormdrewper, can you check the 7.5A fuse with a multimeter? You don't need to remove it, you can measure between the legs of the holder,.

Stormdrewper

@dc42 I do have one but, not very good at using it. What settings would I need the multimeter to be put on to check and what would I be looking for??

Veti

check the resistance of the fuse. if infinite its blown.
see https://www.youtube.com/watch?v=1iHRESNMFAg

Stormdrewper

@Veti excellent, thank you. That seems to be the problem. I don't have any 7.5a fuses laying around but do have a 15a one. Would I be able to use one of those to see if I can get it up and running whilst I order some 7.5a ones??

Veti

@Stormdrewper

no.
and you need to check your wiring for any short that would have caused the fuse to blow.
otherwise the fuse will just blow again.

Stormdrewper

@Veti I've removed all wiring already and going through it with a fine tooth comb. I'll order some fuses now.

Stormdrewper

Thanks guys for your help

dc42

Can you tell from looking at the fuse whether it has blown in the middle of the loop of wire inside it, or at one of the ends? This type of fuse normally blows in the middle when it is overloaded, however occasionally they are badly manufactured and fail at one end.

A common reason for the VIN fuse blowing is connecting the VIN power the wrong way round (I have done this myself!). However, if the blue VIN LED lights up, then VIN must be connected the right way round.