Tuesday, March 18, 2014

Narrowly averted disaster!

So while chasing DX all over the bands tonight, and after a great QRQ session with KC0VKN down in Iowa City, my 590 went deaf.  Like super deaf.

As you would, I checked everything - antennas still up? yes, selector on right antenna? yep, RF gain up? Squelch off? RX antenna selected? everything was in order but still no received signals.  I even got my MTR hooked up and couldn't hear that in the 590's receiver just inches away.  Something was definitely wrong.

I came up and told my wife the bad news. This was not going to be a cheap repair, several hundred bucks for sure.  There goes the Dayton budget!

So while I moped and we watched TV, I did some searching.  I found a reference to a failure mode that caused the receiver to "die".  It looked promising but it was limited to certain serial numbers - B0AXXXXX being the last of them to have this problem - a tiny surface mount fuse opening up for no good reason.  Kenwood replaced the 325mA fuse with a 500mA fuse in the B0BXXXXX serial numbers.

A glimmer of hope!

I rushed down to check and sure enough, my serial number was in the right range for this to maybe be the failure.  I did some more searching and found pictures locating the fuse on the board and when our program was over, I ran down and sure enough, the fuse appeared open and it was one of the early 325mA ones.  I quickly tacked a component lead across the fuse and the receiver came back to life!

Of course you can't just go buy a new SMT fuse so I hit up Digikey and put in an order for a few of them.  A whole 23 cents a piece!  And to think I was almost ready to box it up and spend several hundred dollars to get some puny little fuse replaced.  Crazy.

The new fuse(s) will arrive in a couple days and I'll try to take some pictures while I repair the rig, but for now, off to bed!