What could cause TOTAL RX power failure??
06-08-2013, 05:47 PM
What could cause TOTAL RX power failure??
I upgraded from DSM 2 to DSM X while also switching from my 12X to the DX 18 as well. I have so far changed 3 turbine jets to the AR12120 DSM X 12 channel power safe RX and 1 50cc gasser to the DSM X 9 channel power safe RX
I have been flying the new transmitter with these RX receiver for about 2 months with no issues at all. Everything has been perfect.
However, today my turbine entered "failsafe" and shut itself down. (luckily I was on the ground). I had a complete and total power failure. The remote antenna's had no lights on them, none of the servo's would move. It was like I had unplugged or turned off the batteries. I never had this issue before and should have investigated more but what I did was change the batteries one at a time. After changing the 1st battery still no power, after changing the 2nd battery the system powered itself up. I did not touch any switches or anything other than the batteries one at a time.
I am afraid to fly as I absolutely would have crashed had I been in the air!!
I tested the 1st two batteries and they had plenty of charge. No battery issues.
I have attempted to duplicate this issue by:
1. Going back to the 1st set of batteries
2. unplugging one battery at a time and wiggling the wires and then plugging in the 1st battery back in while I unplugged the 2nd battery and wiggling those wires.
3. I unplugged the remote antenna's one at a time and replugged it back in prior to unplugging the next remote antenna.
I did this both with the turbine running and not running and have not been able to duplicate the problem. I have run 2 tanks of fuel out of the turbine on the ground playing with the wires and attempting to cause a failure. I can't make it fail again.
Lastly, I don't think it was the TX not transmitting because when I had the power failure, both my rudders (bobcat) were in a right turn. When I turn off the transmitter, the gyro on the rudders still keeps them straight and so I feel it was not the transmitter failure. The only way I have been able to get the turbine to enter failsafe and shut off is to turn off the transmitter but if the RX still has power than the rudders stay straight.
Anyone have any thoughts as to what the problem could be??? I will replace the RX and start over if it will prevent a crash but don't know if it could be anything other than the RX.
06-08-2013, 09:04 PM
RE: What could cause TOTAL RX power failure??
As I read your post, my first thought was, how old are the switch/ switches.
The switch is the first thing to fail, unsually, followed by "Y" harnesses.
So have a think about your switch/ switches, & decide if that may be a possible weak point in your system.
Also, check your battery leads, for any corrosion, if I'm reading it right, you are in Florider, I bet it is a bit humid there sometimes,
& can be a source of corrosion.
Cheers
06-09-2013, 03:57 AM
RE: What could cause TOTAL RX power failure??
Leo
06-09-2013, 04:04 AM
RE: What could cause TOTAL RX power failure??
Here is what happened:
I upgraded from DSM 2 to DSM X while also switching from my 12X to the DX 18 as well. I have so far changed 3 turbine jets to the AR12120 DSM X 12 channel power safe RX and 1 50cc gasser to the DSM X 9 channel power safe RX
I have been flying the new transmitter with these RX receiver for about 2 months with no issues at all. Everything has been perfect.
However, today my turbine entered ''failsafe'' and shut itself down. (luckily I was on the ground). I had a complete and total power failure. The remote antenna's had no lights on them, none of the servo's would move. It was like I had unplugged or turned off the batteries. I never had this issue before and should have investigated more but what I did was change the batteries one at a time. After changing the 1st battery still no power, after changing the 2nd battery the system powered itself up. I did not touch any switches or anything other than the batteries one at a time.
I am afraid to fly as I absolutely would have crashed had I been in the air!!
I tested the 1st two batteries and they had plenty of charge. No battery issues.
I have attempted to duplicate this issue by:
1. Going back to the 1st set of batteries
2. unplugging one battery at a time and wiggling the wires and then plugging in the 1st battery back in while I unplugged the 2nd battery and wiggling those wires.
3. I unplugged the remote antenna's one at a time and replugged it back in prior to unplugging the next remote antenna.
I did this both with the turbine running and not running and have not been able to duplicate the problem. I have run 2 tanks of fuel out of the turbine on the ground playing with the wires and attempting to cause a failure. I can't make it fail again.
Lastly, I don't think it was the TX not transmitting because when I had the power failure, both my rudders (bobcat) were in a right turn. When I turn off the transmitter, the gyro on the rudders still keeps them straight and so I feel it was not the transmitter failure. The only way I have been able to get the turbine to enter failsafe and shut off is to turn off the transmitter but if the RX still has power than the rudders stay straight.
Anyone have any thoughts as to what the problem could be??? I will replace the RX and start over if it will prevent a crash but don't know if it could be anything other than the RX.
A friend, who had an aircraft with an AR7010, had a similar problem and traced it to a loose pin on one of the connectors coming from the Switch Harness. Wiggling the wire would cause the power to come Off and On to the Rx.
Bad connections in the wiring are more often the cause of Power Failure than the Rx failing.
06-09-2013, 04:53 AM
RE: What could cause TOTAL RX power failure??
1. the switch is brand new and came with the brand new RX and is supposed to "fail on" - fail safe switch.
2. The switch goes directly into the RX with NO extensions
3. I am not using any Y's - batteries go directly into the receiver leads
4. the batteries are also purchased brand new at the same time as RX and TX
5. No corrosion on the leads. - I checked them.
I did not think to wiggle the switch lead where it enters the RX incase the RX has a loose pin. Good idea I will try it today and report
thanks guys for the ideas
Rick
06-09-2013, 08:44 PM
RE: What could cause TOTAL RX power failure??
Some of the connector pins on leads may be a bit loose when mated with the corresponding pin.
Usually you feel this as an easy mating connector.
Use "keepers" or even masking tape to help insure that connectors stay mated.
Use double pole switches with the poles wired in parallel.
With 3D/Hi G models, it's not a bad idea to use foam wire guides or even double sided tape to secure the wires/connectors
so that they don't "flop around".
I had a NMIH rx battery that was intermittent. Turned out that one of the pins was a bit loose when mated.
It seemed to work OK most of the time, and flexing the cable didn't show the problem. I finally replaced the connector and used new pins.
No more problem.
06-09-2013, 10:32 PM
RE: What could cause TOTAL RX power failure??
Alan, Are you saying the ''Y'' are failing due to corrosion. If so, what to do to eliminate the problem. In other words is the construction of these items the problem or is it due to bad materials etc. Thanks for reply.
Leo
NO I'm saying swiches fail when they are old, & "Y" leads can fail too, corrosion can cause failures where the pins connect to extensions & RX's.
On here we have to try & guess what the fault might be, without any knowledge of the age of the leads, batteries, switches, whatever.
All I'm saying is check for corrosion in high humidity or salt laden (seaside) areas, that's all.
Cheers
06-10-2013, 05:05 AM
RE: What could cause TOTAL RX power failure??
Fail safe switches open to apply power, so I wouldn't worry about that but if you suspect the switch, just unplug it while testing, that will leave the power on, or run a servo extension and just use a bind plug as the switch.
06-10-2013, 05:52 AM
RE: What could cause TOTAL RX power failure??
A few more very important questions.
What battery chemistry and how many cells in each pack? Also any regulators between the packs and the Rx inputs?
What were the blue battery lights in the AR12120 doing when the power failure occurred?
Malcolm
06-10-2013, 08:09 AM
RE: What could cause TOTAL RX power failure??
I had a couple problems with my Powersafe AR 9210s. First, ... The adapter cable that plugged into the Rxer's Main unit was bad on one. I had to go through a couple of these to get a solid consistent connection. The MPX connection pins were bad (i.e. inconsistent depth in plug molding and inconsistent gap between connector halves.)
Also, there are several undocumented things you can do with the Main Unit's switch array (e.g. like inadvertently change the Voltage supplied to the servos or even just change the voltage on one side of the Main Unit.) Once you mix the two voltages, I had all kinds of unexpected indications. I also somehow did a manual reset using the Main Unit's switch array. That time, I had inadvertently eliminated my pre-set failsafe which included an engine kill.(update: looks like they discontinued AR9210s. Wonder why, eh?)
There is a lot of discussion in a couple threads of mine about the problems I had with the Powersafe AR9210. I even had Dan Smith and Andy involved when I was trying to figure things out. They just don’t have this undocumented stuff in the manuals.
Oh, ... If you have them, make sure you have the remote Trouble Indicating LEDs installed so that you can see on the outside of the plane when the things start acting up. From my experience with the AR9210, these are usually the first indicator of a looming issue.
In the end, they did actually replace one of my AR 9210s. The voltage was too high. Since then, we discovered it is capable of two output voltages. They have the bulletin describing how to toggle the voltage on the web site. Guess what. You do it with the on/off switch array. Since it was replaced and I know how to NOT inadvertently switch the voltage, I have been able to figure out what was/is going on and have been able to avoid further issues.
I think you havea different soft swtich arrangement. But my guess is the switch.
06-10-2013, 10:54 AM
RE: What could cause TOTAL RX power failure??
The 2 batteries are 2 cell LIFE w/ 2,200 mah
No voltage regulators
I did not think to look at the blue lights - I never notice them when I am outside in the sunlight. I actually forgot they were there.
06-10-2013, 10:55 AM
RE: What could cause TOTAL RX power failure??
I have no adaptor cables of any kind on the batteries or switch. Everything is plugged directly into the RX.
06-10-2013, 11:07 AM
RE: What could cause TOTAL RX power failure??
1. If I send RX and TX in they can check them and repair/replace as needed.
2. Other causes for this problem could be a bad servo or servo lead. I would have to get a load tester on each servo and replace all wires and leads.
I find it hard to believe a servo going bad or a aging lead would cause the whole system to shut down!! - I have seen/heard servo's start to act up and need replacing but never seen or heard of them killing the entire system.
I used to think people who say - the radio failed were to proud to say "i crashed" However, I am now not so sure. I surely would have been one of those guys saying I didn't have any control had this happened in the air!! - I am lucky to have it occure on the ground but now need to be sure it is resolved before it happens in the air. I am now thinking, I have 4 plus years flying this plane and maybe I should pull out all the servo's and leads and do a complete refurbish of a nice plane. It is worth it as opposed to crashing and having to pay to get turbine fixed, buying a new plane and having to replace the crashed radio equipment. What do you guys think of horizon's response??
06-10-2013, 01:00 PM
RE: What could cause TOTAL RX power failure??
06-10-2013, 05:14 PM
RE: What could cause TOTAL RX power failure??
Unless a servo or servo wire was shorting (i.e. exessive load), I can not see how a servo would crash a Rxer. Seems like you could find that by checking resistance of each servo at the Rxer connections. Or, ... You could swap out the Rxer for another and see what happens. Or, .... just get the servo programmer out and test each servo/servo wire circuit. Lots of things to test before ripping out wires and harnesses.
Agreed, I am not sure I want to rip everything out of a great flying plane, I don't want radio failure and to crash it either
06-11-2013, 12:26 AM
RE: What could cause TOTAL RX power failure??
From your description of what occurred and your setup I'm betting the problem is either in the receiver main unit or more likely the softswitch and harness. I agree with your and others assessment that its very unlikely that a faulty servo or harness could cause enough of a load to pull both batteries down to a level that would cause the receiver to shut off and even if there was one, why did replacing a battery cause the fault to clear?
My guess is the softswitch itself and I bet you switched it on and off a few times while you were changing the batteries and this cleared the fault. The softswitch works by shorting the signal wire to the ground wire (-ve) to switch the receiver off and opens this connection to power it on. I think you should open the softswitch housing and check there are no stray strands from the soldered ends onto the switch itself that are touching. Also check that any cable restraint (usually done by having two bits of the switch housing moulding pressing together and trapping the cable) hasn't pushed through the insulation and is intermittently allowing the wires to touch. Spektrum have had problems with the softswitch in the past where the unused +ve cable was touching the other pins causing receivers to self destruct. Here's a link to their advisory on how to modify the switch harness to prevent this which should have been done on all current units
http://www.spektrumrc.com/Articles/A...ArticleID=1777
Unless you find something repeatable and obvious in your softswitch I would be inclined to replace just the receiver main unit and the softswitch. I don't think the problem is in your satellites or your servos and wiring and at the end of the day the main receiver and switch are a small part of the cost of the model for the peace of mind a change will give you.
Hope this helps!
Malcolm
06-11-2013, 02:43 AM
RE: What could cause TOTAL RX power failure??
Hi Topgun24,
From your description of what occurred and your setup I'm betting the problem is either in the receiver main unit or more likely the softswitch and harness. I agree with your and others assessment that its very unlikely that a faulty servo or harness could cause enough of a load to pull both batteries down to a level that would cause the receiver to shut off and even if there was one, why did replacing a battery cause the fault to clear?
My guess is the softswitch itself and I bet you switched it on and off a few times while you were changing the batteries and this cleared the fault. The softswitch works by shorting the signal wire to the ground wire (-ve) to switch the receiver off and opens this connection to power it on. I think you should open the softswitch housing and check there are no stray strands from the soldered ends onto the switch itself that are touching. Also check that any cable restraint (usually done by having two bits of the switch housing moulding pressing together and trapping the cable) hasn't pushed through the insulation and is intermittently allowing the wires to touch. Spektrum have had problems with the softswitch in the past where the unused +ve cable was touching the other pins causing receivers to self destruct. Here's a link to their advisory on how to modify the switch harness to prevent this which should have been done on all current units
http://www.spektrumrc.com/Articles/A...ArticleID=1777
Unless you find something repeatable and obvious in your softswitch I would be inclined to replace just the receiver main unit and the softswitch. I don't think the problem is in your satellites or your servos and wiring and at the end of the day the main receiver and switch are a small part of the cost of the model for the peace of mind a change will give you.
Hope this helps!
Malcolm
I did NOT turn the switch on or off until after the fault cleared itself. That is the weird part for me.
Thank you for your thoughts. I think it has to be in the receiver as well. I will go to the local hobby shop and try to get a "servo tester" or some type of "load tester" just to be as safe as possible. I will replace the RX and remote's to also be safe.
06-11-2013, 05:03 AM
RE: What could cause TOTAL RX power failure??
06-11-2013, 07:15 AM
RE: What could cause TOTAL RX power failure??
I had exactly the same thing happen on the same rx in my 100 cc yak. It was all new . It was a bad remote rx cable. . IT took forever to find. I cant explain why but i replaced the remote cable and have no issues in 100 flights. My bad cable was the longest cable that came with the radio. I too am using a dx18 . Hope this helps
06-11-2013, 11:50 AM
RE: What could cause TOTAL RX power failure??
Typically, remote Rxers have LEDs that indicate if they are working or not. If there is a momentary loss of connection, mine blink. If there is total a loss of power, they do not light at all. And, ... if the Main Unit detects a problem with a remote Rxer on startup, the Main Unit will not "Arm." If there is a problem with a Remote Rxer after the Main Unit is powered on, the system will work until you shut it off. Then it will not repower/arm until you fix the Remote's problem. As I understand it, that is the concept behind the "Powersafe" units. At least my AR 9210s work that way.
Those Remote Rxer connections seem delicate and fragile to me. When I make a connection of these, I get the extra lamp and magnifying lenses out. Also, I support their harnesses fairly close to the connection. I also added some additional vibration proof foam in between the Main Unit and the Fuse (i.e. sandwiched foam between the Fuse deck and a piece of Plyboard, then mount the Main Unit's rubber feet on the plyboard. I put in a cross brace to support the Rxers' and other wiring, at the exits for the Remotes.)
06-11-2013, 06:40 PM
RE: What could cause TOTAL RX power failure??
The manual states
NOTICE:.
In order for the system to operate, one remote receiver must be
plugged into receiver port A and two more receivers must be plugged into
any other ports. When binding the PowerSafe with three remote r
eceivers, if a
fourth remote receiver is added, the system must be re-bound to recognize the
additional remote
06-12-2013, 05:12 AM
RE: What could cause TOTAL RX power failure??
I replaced mine and got lucky it was the first one i tried. I had no blinking lights either. It was the port A cable on mine .Also there has to be 3 specific remotes working on that rx for it to power up.
The manual states
NOTICE:.
In order for the system to operate, one remote receiver must be
plugged into receiver port A and two more receivers must be plugged into
any other ports. When binding the PowerSafe with three remote r
eceivers, if a
fourth remote receiver is added, the system must be re-bound to recognize the
additional remote
I can not make it fail again. I could change all the wires but I do not know if the problem is in a remote wire, the RX or something else... That was my question back to you who changed the remote wire and have had success.
I was very disappointed with the response I got from Horizon Hobby. Basically, I don't this the tech I spoke with knew anything and was just covering his you know what...
06-12-2013, 12:58 PM
RE: What could cause TOTAL RX power failure??
For these complex receivers, you have to press hard the Tech on the phone to contact their Technical Support people. I pressed them hard and was given Dan Smith as a good contact. They had him call me initially. Then we had several email exchanges. He took the time to fully understand my AR9210 problems and pursue answers to my questions. It took a couple days, but he got me the answers the other Techs could not provide. He also figured out that there were a couple undocumented features that were causing my problems.
Previously, I had even sent the failed one in and they sent it back saying it was working. Then, I sent it back again and they replaced it. The new one exhibited the identical problem. (i.e. wrong output voltage) Then, I got Dan involved. Dan figured out that they were both working correctly, just in an undocumented mode. (i.e. The ads and Manual's Specs said output was 5.9 VDC and the actual unit was putting out 7.3 VDC. You can toggle the voltage and you have to do it individually to both sides of the Main Unit using the On/Off Soft Switch) . If you do not watch closely what you are doing when you turn it on and off, you toggle the voltage. Now, I watch the buttons closely when I press them and I no longer have any problems with the thing.<o
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Also, what I failed to do when I sent it back was send everything back including the EC3 to MPX adapters and the Remote Rxers. When you send something back to them, they want everything that came with it, even if you have to rip several components that do appear to be working correctly back out of the plane, etc. I learned to not install things such as Remote Rxers permanently. Now I use Velco only. Also send the adapters. I had one that was intermittent.
Funny thing about the AR 9210 though; They are still advertising it in the current Ultimate Acrobatics magazine. But the Horizon web site says it was discontinued. Go figure! I personally think when Spektrum started selling Powersafe products, they did not quite have all the loose ends initially figured out. They certainly did not have the AR9210 or its manual figured out. The typical Horizon Techs could not solve the problem. I guess this is one of the risks we take when we use the latest and greatest products. We become the Beta testers.
