MFJ-259B

[88_bandit]

Yeah I recently acquired this antenna analyzer From a friend of mine and he said it worked fine until he wired up the power cord backwards and plugged it in! It was the right voltage just the wrong polarity. It will not power on now not that I’m surprised just want to find out what all I need to do to repair it may be a simple polarity protection diode? Any help would be greatly appreciated

 

[doffo]

At this point may as well have a look around that area where the power first comes in. Something like this happened when the wrong power cord was used on a Sega CD attachment. Wish I was more knowledgeable as a kid so I could of had a fighting chance to save it.

Hoping something is visible that may of failed.

 

[sp5it]

Schematic attached.
There is big chance, that PIC didn't survive.

 

[88_bandit]

Ok looks like d9 is shorted and q13 is blown apart