Overvoltage spike killed my V4


John Faivre
 

My power supply regulator failed. The crowbar circuit kicked in at 15v and blew the fast blow fuse, but my board is dead. The voltage could have gotten as high as 27v before the fuse blew.

The 2 amp fuse blows as soon as it is powered on. I don’t see low resistance on either the main or final power circuits. I’ve meter checked all the transistors, diodes, an caps.

I have disconnected everything from the main board and it still blows. The Raduino still works if powered from the USB port.

Anyone have an idea how I might trouble shoot this?

I May be in the market for a V4 or V5 board, if anyone had one to sell.

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John Faivre WA9SGD

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