Large Scale Central

Spektrum DX5e Intermittent loss of link - SOLVED :)

Problem Solving
#1

For the last month or so my DX5e has been misbehaving; intermittently loosing the radio link between TX and RX. It started out as a once-in-a-while problem but in the last few days it has become chronic, almost to the point of crashing a train today due to loss of control. I was going to post here to see if anyone had any ideas, but decided to Google the symptoms first. Glad I did because the first R/C forum post I read described my exact symptoms and a logical cause.

The radio will loose the link with it’s RX at seemingly random times. I found that tapping on the TX body would restore the link for a while. The post I read, which included a Youtube demonstration of the symptoms, showed me that it was easy to cause the link loss by tapping on the TX case or power switch.

It seems that Spekrtum uses a DPDT switch for main power. One pole of the switch powers the LED battery indicator while the other pole powers the actual transmitter. A poor solder joint on the switch causes power to be lost to the TX components while the LED indicator remains lit.

The fix was to open up the case, find the 6 pins for the power switch at the top of the main circuit board, heat each one and add a tiny bit of solder. Since heating all 6 joints I can no longer cause the TX to loose it’s link with the RX.

I am now a very happy camper :slight_smile: :slight_smile: :smiley:

Youtube video (embedding was disabled): http://www.youtube.com/watch?v=Je764AvkRlQ

#2

Very interesting. Thanks for the heads up. I haven’t seen any problems like this. In general, I think the Spektrum gear is pretty good quality, although I did just have to return a DX5e due to a failed Elevator channel.

#3

From what I’m reading on the R/C boards this is fairly common, but only with the DX5e.

Railboss’ cruse control is great when you want to save TX battery power, but scary as heck when you loose the link on a point-to-point railroad with the throttle open :o

#4

Imagine the fear you’d experience with an airplane doing 100mph at the end of that transmitter signal!

#5

A very good tip on a US RC forum advocated opening the back of any new transmiter, tipping it upside down and shaking it. Quite often bits of solder and/or tiny pieces of cut wire drop out. Not good if left in place – good for short circuit and corrupted signals tho’. Far East QC again…:slight_smile:

#6
Mark V said:
Imagine the fear you'd experience with an airplane doing 100mph at the end of that transmitter signal!
I read a lot of horror stories about lost / crashed planes. If one is foolish enough to fly a very fast and expensive plane using the cheapest radio system they make, then they have decided to accept a risk. The DX5e was designed for use with foamies and dual rotor helis. With those, a crash is usually not catastrophic.

You can set the fail safe on the RX to do whatever you want on loss of signal. I think most pilots fail safe to throttle down and wings level. As long as you have some altitude recovery might be possible.

#7

I get your point but even “foamies” can be dangerous…I know of one that reached 192mph! I would never use such a basic radio for my aircraft. I am genuinely concerned as I see so many beginners showing up to the flying field with cheap “RTF” crashes waiting to happen. Low cost definitely has a down side.

Specktrum has reported counterfeit DX5e radios being widely produced; I wonder if that is the source of the “bad” radios? If you go to their website and click on the DX5e link it states all DX5e’s sold through KoKo are fake.

#8

Back when we didn’t know any better, a friend and I took one of his wrecked beyond repair U-Control planes, stripped it down to fuselage, elevator and vertical stabilizer (we broke off the rudder) and its .049 engine. We fired up the .049, pointed it straight up, let it go, and watched it go out of sight. It finally stalled, but not before running out of fuel. It slammed into the street at full throttle, and dug a 6 inch deep hole in solid concrete.

Nothing, I mean nothing was left of that wreck.

We hightailed it out of there before anyone could ask any questions.

#9

I purchased this radio from Tower Hobby, so I’m pretty sure it’s genuine. The receivers I picked up from OO Models in China, I’m not so sure about. I figure with an F scale train doing about 15 scale MPH it’s probably pretty hard to injure 1:1 people, so I think I’m safe :slight_smile:

BTW - OO models is showing all Spektum products as Sold Out, so the probably got cracked down on.

#10
Jon Radder said:
I purchased this radio from Tower Hobby, so I'm pretty sure it's genuine. The receivers I picked up from OO Models in China, I'm not so sure about. I figure with an F scale train doing about 15 scale MPH it's probably pretty hard to injure 1:1 people, so I think I'm safe :)

BTW - OO models is showing all Spektum products as Sold Out, so the probably got cracked down on.


Really , you purchased a Spektrum radio from Tower Hobbies ?
Horizon Hobbies will be glad to know that Tower is now selling their product .
Of course anything is possible I guess .
Thanks though , good to know of problems with the DX5e , I have not purchased a DX5e Spektrum myself , ALL the reast of the Spektrums , but not the DX5e .

#11

Sorry. It must have been Horizon. It may have been via an eBay store, but I really don’t remember. I’ve bought most of my servos etc. from Tower so I just assumed that’s where the SX5e came from. It’s been a long time.