[Going Balistic]

It has been a few years since I have flown; 5 in fact, but I don't recall the issue that I am having now ever coming up before.

I have an ACE fast field charger that I bought approximately 7 years ago to charge my TX and flight packs at the field.

Thinking that my flight box battery was slightly undercharged I decided to use the Hobbico charger and battery from a friend at the field. The Hobbico charger blew the fuse in the XP783 when we turned it on.

First issue:

The fuse in the XP783 was a 250ma fuse. I dont recall ever changing the fuse in the radio but the other guys at the field who fly JR (one of which is a XP783) all have 3 amp fuses in their radio.

What is the correct fuse for this radio?

Second issue:

Why did the fuse blow?

Third issue:

Once we replaced the fuse, with another fuse (200ma) the radio would not charge on another Hobbico fast field charger or did not charge on the ACE charger in my flight box.

Fourth issue:

I replaced the battery in the radio after not using it for 5 years. The battery I replaced it with is a 940mah. Does the capacity of the new pack come into play here?

Any JR experts out their? I am quite familiar with basic electronics but this one has me a little concerned as I don't want to damage the radio set.

Thanks,

GB

[Tiger]

Are you aware that the JR charge plug is backwards from other radios? You may have inadvertantly plugged it in backwards thinking it was the same as futaba or the like. I have to remember that red goes to black and black has to go to red on my charger to correctly charge JR radios.

You may have damaged the radio if it was plugged in backwards.

The MaH of the battery has no bearing on the issue you are having.

[Going Balistic]

Hi Tiger,

I should have mentioned in my first post that I used the correct JR connector and polarity (as I remember, as I knew I was in for trouble if I didn't).

I flew with the radio today after range checking, etc. and had no problems.

If damage was to occur in the radio would it show up immediately or what should I expect?

Thanks,

GB

[JimMoss]

Have you tried fast charging it again?

And do you have a cycler?

Jim Moss

[nony]

3 amp is the correct size... My son has the same problem with his 783 for some reason - blowing 3 amp fuses on a computer controlled charger that cannot exceed 1.00 amp max...

We have had some success with the slow blowing fuses from Radio Shack, but always carry spare fuses in the Tx case - just in case..

[Going Balistic]

Thanks for the info.

I was able to fast charge the same day by taking the battery out of the radio and hooking up directly to the charger.

I have not tried fast charging in the radio again since this incident.

I don't currently have a cycler but coincidently have been looking very closely at purchasing one. I believe I will pick up the Great planes Triton.

Jim, do you think there may be a problem with the pack? Am I reading too much into your post?

[JimMoss]

Not trying to make you nervous.

I just like to cycle batteries especially newer packs to make sure the capacity is there.

Jim Moss

[Tiger]

Hi BG,

If the radio had been plugged in in reverse, the damage would most likely be immediate. But you've already covered that, so I'm sure your fine. Why the fuse blew is interesting though. I wonder about the Ace charger though. If it had a problem and put to much current into the radio to blow the fuse and possibly even burn the wire inside connected the the charge plug. Might be the reason another charger won't charge the battery while it is in the radio. I would open it up and take a look at the wiring from the charge plug to the fuse.

Also, if the charge rate was more than 250 maH, then you simply may have blown the fuse again. I can't imagine why a 3 amp fuse would be in these radios? Who charges that high? I'm not 100% sure where the fuse is in the circuit either, so I'm just fishing a little here. I do not have a schematic of this radio to be sure.

Tiger

Originally Posted by Going Balistic

Hi Tiger,

If damage was to occur in the radio would it show up immediately or what should I expect?

GB

[Sport Flyer]

I'm also a JR user, and I also have an ACE FFC. Its never blown a fuse in either my 783 or my 8103. Both came with a 3 Amp fuse. I suggest trying it with a cycler first, as well.