RCFREEK

I totally lost control of my majestic 1400, which had done about 20 flights. Coming out of a snap roll, the plane stopped responding, jammed at full throttle and a 55deg decline angle. Thus, i saw catastrophe !! What could the possible reason be? I remember i had secured the battery in the fuse. The only possible assumption could be that the batt somehow came loose.

On top of everything, the receiver doesnt work anymore. when i plug in the batt to the rec, there's power to the servos for a milli second, then a complete blackout. Could it be the crystal? Should i fly this receiver again. Its a JR PCM 649S with a 3810 radio.

I'd appreciate comments cz i need help.
thanks

Highflight

My Feedback: (4)

I'd agree that in the case of loss of all immediate control, an unplugged battery is the first place to look.
As far as the receiver, the crystal is the most fragile part of it so if you don't want to spend the money to send it in and have it bench checked, what YOU can do is to pull the PC out of the RX case and look at is closely for any cracks or burns or any visual indication of damage. If it all looks good, stick a crystal in it from one of your other (same brand) receivers and fire it up. If it responds, then the crystal can be assumed to have been trashed in the crash.

Highflight

RCFREEK

Thanks for the help. Anyway, this morning i swapped this crystal set with another one n it worked so ur right about the crystal being trashed in the crash. As far as the rx body's concerned , there is a crack on it. I opened up the rx n there seems to be no burn inside, the rest i dont know how to check.
Is the rx 100% safe to fly with? if not, what do i do?

secondly, u seem to be a pro in this trade so could u tell me about zen 50 by world models cz i cant seem to find any reviews on it. Im thinkin of buying it.

thanks again

SwampFlier-RCU

There are number of threads here on RCU about the xen 50 it's a good airplane, very well built. I was going for one but settled for a Cloud dancer based on my skills at the time and teh COst$$

apteryx

100% guarantee that it's OK ?? I don't think you get that on new stuff.

I wouldn't fly that receiver until I had it thouroughly checked by a R/C manufacturer's service organization. Radio South, for example.

Highflight

My Feedback: (4)

If you're talking about the outer plastic case when you say "body" (and not the PCB), then that's proof that the RX took a pretty good hit but the electronics may be fine.

There's different ways to go so you pick what makes you feel good:
1. Put a brand new crystal in the RX, put it back in your plane, and range check the bejeebers out of it. Importantly, make sure you do a range check with both the motor off AND WITH THE MOTOR RUNNING. The vibration of the engine running should help to expose any damage to the electronics from the crash. If your range check distance is good, go fly (with trepidation and great care for a few flights).
If the case crack is just a minor crack, it should give you any problems. You're going to wrap it in foam anyway, and besides, SOME guys who fly the really light park flyers actually take the RX PCB out of the case to save weight and then just wrap the PCB in foam. I think that's foolish, but that's just me.
2. Send the RX in for service so it can be bench checked on a scope. They also (usually) perform a vibration check so it might make you feel better to have a "pro" give it a once-over.
3. The ultimate fix is to throw it away and replace it with a new one. Maybe it's hard for you to accept the extra expense, but it always sounds cheaper if you reflect a moment on how much you have invested in your entire aircraft. You MIGHT look at the cost of a new receiver as "insurance".

Personally, I've made all of the above choices at different times so there's no hard and fast rule.
The real question is: "What are YOU comfortable with?"

Highflight

RCFREEK

I guess i'll give it a rigorous range check with n without the engine running, to ensure vibration doesnt bring out any unforeseen flaw, That too on a trainer. If in any doubt , i'll replace it as a last resort. Thanks anyway.