Rx crystal problems - Need Help

[Rastaman]

I am flying a Raptor 50, using Futaba 9CHP and R149DP Rx. Yesterday while flying I was hovering about 3m high and suddenly my engine went to an idle and I had no control, no response from any stick movement. The heli came down and crashed. Luckily I had failsafe enabled so it came down level and not as hard, but hard enough for damages. After heli crashed engine was still running at idle and I couldn't use throttle cut because there was no response. Disconnected fuel line from carb to shut engine down. Started troubleshooting, I turned my Tx on and off a few times and did the same with the Rx still no response. Decided to check Rx crystal, replaced it and everything worked.

This is the second time I am experiencing this same problem, the exact scenario happened 3 months ago at the same field and it was the Rx crystal also. There were other fliers but I am certain that my frequency was cleared. Has anyone experience this problem? What could be causing Rx crystal to just die? Could it be something in my Tx?? This is extremely frustrating and I would appreciate your insights.

[Alfred]

Since the receiver appears to be okay (as you said it lasted 3 months before it happened again), then the most likely causes would be these:

1) Excessive vibration in the heli, shaking the crystal to death
2) Not enough padding/soft-mounting for the receiver....see above
3) crystal not taped in causing it to partially come out

[Rastaman]

Thanks for your response. Your points 2 and 3 cannot be, my receiver is in a receiver box which has foam and the box is kept closed by 4 (3mm) bolts. For the crystal there is a plastic cover that snaps in and keeps the crystal secured. As for point 1 i guess this is possible, however I don't think my heli is vibrating more so than the other R50s that fly at the same field using same receiver. So it's still a mystery.

[WayneBrown]

I agree with Alfred's response. Mechanical securing of the crystal is best achieved with tape.
I dont care for the reciever boxes myself, I like to be able to check things out occasionally, so I wrap it in foam and secure with stretchy velcro.

[Rastaman]

Thanks guys for your suggestions! I will repackage my Rx with foam, eliminate the Rx box and secure the crystal with tape. One last thing, the question I asked before....Is there a possibility that this problem be caused by my Tx??

[Alfred]

Is there a possibility that this problem be caused by my Tx??

Yep

[Rastaman]

In what way and how do I verify that it is the Tx??

[Alfred]

If it is like or a JR TX then pull the RF module and see if the pins in the TX case are corroded.
Clean them by pushing a pencil rubber into them a couple of times carefully and then wipe them with a clean rag..NO chemical cleaners!!!!
Do the same with the RX + TX crystal.
Gentle is the word!!
Other then that, send the equipment in for service.

[Rastaman]

Got it, thanks for your insights!!