JR XF421EX

I'm in a similar situation as you. Had my XF421EX for several years now, use it with FMS now and again, but trainer is still a work in progress.

Do you have the knack for getting it into System Mode? Scroll and Inc+ pushed up when transmitter is turned on. Page 16 of the manual.

The problem you describe sounds like Wing Type Selection. Enter System Mode, press Scroll untill MIX WNG apprears on screen. Page 19 of the manual.

Sorry for quoting the manual but you didn't say exactly where things went wrong for you. Are you further advanced than the above when you get stuck?

Ahh, now I see your problem. I've just worked through the manual and guess what, ITS WRONG!

The manual indicates that flapperon and delta are to be switched on and off.

However, using +/-inc on my 421, it cycles through the options like this:

WNG OFF > FPR ON > DLT ON

So if one exits system mode when FPR ON is showing, then flapperons remain in effect. Exit with WNG OFF, then none of the above remain in effect. The inc buttons only scroll through the options.

However, V-tail is different. If WNG OFF or flapperons (but not delta) then the channel button opens VTL options. In this situation, the inc button _will_ turn V-tail ON and OFF. I actually got flapperons and V-tail at the same time on an ill fated foamy slow flyer that I attempted last year.

Could it be possible that XF421EX has variations in firmware? Does anyone have a set that agrees with the manual.

wdnshu wrote:

Mr.Branko you are a genius.The voltage was 3.85, after charging 5.05V and all problems seem to be solved.How long is flight time on a fully charged flight battery?.Thanks again. Wdnshu

Greetings Wdnshu,

Hmmm, flight time... well that depends on lots of things. Number and size of servos, battery health, flying style, risk taking etc. Questions like this have resulted in mixed opinions on this newgroup. When discussed I came to the conclusion that most flyers top up before a day of flying and don't worry too much.

However, may I make > Mr.Branko you are a genius.The voltage was 3.85, after charging 5.05V and

I was thinking the same thing. 5.05V is not good. Cycle the RX battery a few times and see what it gets to. mk

Hi I hope someone can help me.

I have a radio XF421EX JR. unfortunately my brother plugged it into a charger with poles reversed what caused the radio does not turn on again. I wish someone would tell me the right way to solve this problem, the radio has a very personal value and really did not want to get rid of the radio. I'll be grateful to the person who can help me.

Thanks ... Greetings ...

The JR transmitters I have been inside, have a fuse. It is mounted on the main board, under the battery pack in the transmitter. Look and see if yours has one and if it is blown. If it is, it might be a quick, easy fix.

BobH

| On 10/17/2012 10:36 AM, eduar2079 wrote: |> Hi I hope someone can help me. |> I have a radio XF421EX JR. unfortunately my brother plugged it into a |> charger with poles reversed what caused the radio does not turn on |> again. I wish someone would tell me the right way to solve this problem, |> the radio has a very personal value and really did not want to get rid |> of the radio. I'll be grateful to the person who can help me. |> Thanks ... |> Greetings ... | | The JR transmitters I have been inside, have a fuse. It is mounted on | the main board, under the battery pack in the transmitter. Look and see | if yours has one and if it is blown. If it is, it might be a quick, easy | fix.

That's quite likely. Though if that fuse were burned out, the radio would probably still work -- it just couldn't be charged. Though of course if the battery was dead then it wouldn't work very well, would it?

If one had a general purpose R/C charger, one could charge the battery pack outside the radio and see if the radio worked once it was put back in.