Junkyard Coil issue

[MartinY]

Hi all

I've got a problem with my Junkyard blowing fuse F103 (high power solenoids). After a little diagnosis, it appear that the one of the coils (Refrigerator Popper) is receiving a pretty constant 70v (should be 50v) even when it isn't being triggered. I disconnected the coil and measured the voltage across the inputs.

I presume this is a board issue? If so, what should I be looking at?

Thanks in advance!

 

[Poibug]

70v can be common so not to worry.If you do have that across the two cables, I would imagine a driver or predriver transistor has gone.Possible it is a chip driving them but unlikely.Again unlikely is there is a Nick in the ground of the coil ground cable,the thinner oneand it's permanently grounding.You can rule that out by disconnecting the connector that is ground out from the driver and measure between the correct pin on the board and live

 

[MartinY]

70v can be common so not to worry.If you do have that across the two cables, I would imagine a driver or predriver transistor has gone.Possible it is a chip driving them but unlikely.Again unlikely is there is a Nick in the ground of the coil ground cable,the thinner oneand it's permanently grounding.You can rule that out by disconnecting the connector that is ground out from the driver and measure between the correct pin on the board and live

Thanks - I'll try that...

 

[Poibug]

You dont have to use coil live, you could use the 50v test point as that's on driver board too