How much does it cost to replace a fuse?
 

So about a month ago I had a failure of my 430 where I could not transmitt. Receive ok, but on transmitt, the tx light would come on but no one could hear me.

I tried everything (well obviously not). I stuck the 430 in a Bonanza and it worked. I ran new coax, new connectors, new thru tray bnc's, sent in audio panel for repair, rewired audio panel to comm. I spent a rediculas amount of time trying to find the problem.

It was with great dissappointment that I had to take a day out of work and fly the plane to Stark Avionics. I bought 2 planes worth of Avionics from them. I wired both myself and as a homebuilder, this was my last recourse and I absolutely HATE taking my plane to someone to work on.

I spent 5 hours there with 3 technitions. They hooked up every gismo they had. But in the end, they sent me home with no solution and a now broken 430. They inadvertentantly left a test pin in the tray and jammed up the pins when reinserting the unit.

A day later the chief technition called me and said. " Hey do you have a fuse on the comm circuit?"
"Ahh, yeah"
"Check it"
"Ahhh.. OK"

And low and behold, there is my 5 amp fuse blown. He said replace it with a 10 and I did and it now works.

So how much does it cost to replace a fuse?
1 RMA unit
$140 worth of "Troubleshooting time" for Stark
$.37 for the fuse

ARGH!!!!

hehe - been there done that
 

Bet, we know the *first* thing you'll check next time :)...

Yell at me next time would ya. I've got about every piece of RF test gear known to man. Antenna checkers, spectrum analysers, SWR bridges, etc....Comes from being a Ham for over 20 years I guess :)

I'll be installing a 430 shortly. Does the manual call for a 5A fuse on that circuit? Just wondering if I need to watch for that.

Dave

430 indicators
 

The 430 doesn't give an indication that it is not getting power on the comm circuit? That seems like it could use a design update.

A 5 amp was called out by stark when I Installed it.
I guess its 10 now.
5 amp made it 200 hours
Looking at the specs, page 1-3 rev L of the 400 series manual, it is 6amps at 13.75 volts when transmitting. So there you go.

And no there is no way of knowing. There are multiple power inputs for the nav and com on a 430 for redundancy. It looks and feels like it is working if the com fuse is out.

I've had an occasional problem with my starter circuit. I get in, flip the switch, and NADA. I then think it's a wiring problem, battery problem, etc. After tearing into the aft battery deck twice now, I've learned to check the starter fuse first because it was the problem both times.

I've learned my lesson so I can identify with you.

Bummer..
 

In rush currents don't usually apply to solid state circuits, they are generally the product of incadecent lamps and motors start ups.

Now that's what I call a slow-burn fuse. 200 hours! I expect it uses just a tiny bit over 5 amps, and they round it up to 6.

Of Course.....
 

.....if you'd a circuit breaker instead of a fuse, you'd have seen it popped on the next preflight...right? :rolleyes:

Paul rolls and ducks for cover.... :D

fuse vs. CB
 

I think I'm going to rip out all my fuses and replace them with CBs - not! :)