Zor

Hello eveyone,

A new thread trying to keep this situation isolated and focused on.

II am an older indiidual in engineering most of my life.
I think I can read the English language.
Sill I have questions to clarify the operation of a JR DX7 system.

Both Xmtr and Rcvr batteries are well charged.

I followed the binding procedure as written in the manual.
I got steady leds (two) on and the four servos worked.

Many times over about a week I turned on the system many times each day.

Then one day I turn the system on and got the two leds on but had no servo motion.
I shut it off. Always Xmtr on first and Rcvr off first.

Turn the sustem on a second time with the same results. The two leds come on but no servo motion.
Turn it off again.

Try a third time and still two leds on steady and no servo motion.
Now instead of turning things off I go and look at the transmitter display of the servo motion.
Nothing is moving. Not the diaplay cursors nor the servos themselves.

Turn the system off again.

Back on (fourth time) and immediatly go to see the Xmtr display. The cursors are moving.
I look at the servos and they are working fine.

Tried the system many times later in the day and no failure.
Last three or four days, again tried the system many times and no problem.

After dinner tonight I turn the system on and the two leds come on FLASHING.
NOTE: The servos are working apparently ok.

Turn the system off.
After a half minute or so I turn the system on again.
The two leds come on FLASHING AGAIN. The servos are working fine.

-

My understanding from the manual is that there is two conditions for the leds to flash.
1 The system is ready to bind. The Xmtr is NOT ON yet (manual page 21).Then holing the rear button on

(depressed) while turning theXmtr power switch on and in a few seconds the system SHOULD connect

NOTE: I like the wording "should connect" not "will connect". It did and the binding took place ok.

2 The second condition is (per manual) if there was a power interruption to the receiver(s) or a so called "brown out" the leds will be flashing (Again apparently this is not always true depending how old the sytem is.

Mine was bought from a hobby dealer only two weeks ago as new in origjnal manufacturer packaging but i do not have any way of knowing how old it is).

Back to the manual _ _ _ I cannot find anything telling me what to do if I see flashing leds.

I measure he battery voltage and it is 5.15 volts. Well above the 4.8 v.
The manual says it should work down to 3.2 volts.

Now why would the system come on FLASHING tonight when I turned it on an repeated flashing twice again ?

It certainly was not a low voltage. I do not believe in an intermittent battery connection with all new connectors that were connected initially and it worked fine everyday for two weeks (many times each day) except for once the servos not responding. Since the servo display was not showing movement either I attribute that event to the transmitter failure.

Any thoughts or explanations will be much appreciated.
From what I have recently read on some parts of this forum, I am on the verge of loosing faith in Spectrum.

Help please.

Zor

BuschBarber

My Feedback: (2)

If conditions are right, a Brownout can occur. This is usually due to a Voltage Drop resulting in the ReBoot of the Rx. After the Brownout, the voltage of the batteries will return to Normal, so the only record of the event is the Flashing Lights or an indication on the Flight Logger, if you had one.

The best way to try and recreate the event is to Stall all the servos, manually, and see if a Brownout occurs. You can also hook up a voltmeter, during the test, and read the voltage drop.

Zor

What I am talking about is ___

1 The transmitter seem to have had a fault a few days ago and was not sending out command signal. The servo position display on the transmitter screen was not showing any motion response to the stick motions. and the servos were not moving.

2 This evening I just turn the system ON as I did many times in the last few days and I get these blinking (flashing) leds. The voltage was higher than 5 volts (mesured at 5.15 v as written in my first post.

Details are all in my first posting #1. I know it is a bit long to read but I wanted prospective helpers to have a clear picture in their mind of what happened.

Zor

allans

My Feedback: (11)

Can you try a 6 volt battery ( a good one ) and see if the problem is repeatable.

We have a had a similar kind of problem at my club a few years back and all of them were completely resolved by going to 6 volt Rx batts.

Also , just as an a side , have you check the integrity of all of your connectors and the switch in the plane.

Is it a really good switch ?

ACE

JNorton

My Feedback: (2)

Zor,
From your previous posts on different forums I believe you are very detail oriented individual. You've just convinced me to purchase either a Hitec Aurora or a Airtronics SD10 transmitter. I know this doesn't help your problem but it helps mine.

I hope you find a resolution.
John

Rafael23cc

My Feedback: (6)

Zor:

If I read your post correctly, there is nothing anybody here can do for you. It is not a brownout, it is not a problem with the receivers or servos. The problem is definitely in the transmitter and you have to send it in. The clue is clearly when you move the sticks and the servo monitor on the radio does not react to the stick movements.

Rafael

Zor

Hello All,

Quote:

Allen

Also , just as an a side , have you check the integrity of all of your connectors and the switch in the plane.

Is it a really good switch ?

It is the new connectors that came with the Spectrum DX7.

I have disconnected and looked at the connectors metal parts. They are new and clean.

I reconnected them after the first failure.

Quote:

JNorton

Quote:

I know this doesn't help your problem but it helps mine.

I hope you find a resolution.
John

John, _ _ Glad to be of help

Quote:

Rafael23cc

Quote:

Zor:

If I read your post correctly, there is nothing anybody here can do for you. It is not a brownout, it is not a problem with the receivers or servos. The problem is definitely in the transmitter and you have to send it in. The clue is clearly when you move the sticks and the servo monitor on the radio does not react to the stick movements.

Rafael

　

Rafael

I am now of the same opinion as you.

I will be observing the system behavior which is all connected and operating on my dining room table.

It is to go into my new sailplane which is not yet finished and it will take a month or two before it is ready for flying.
I will be switching the system on at least a couple of dozen times a day and seeing what happens.

　

I make an analogy with our computers that suddenly have a glitch one day and the glitch does not show for another two months or never show up again. Example of glitch _ _ _ The screen come up with wrong color scheme one day and then the problem never show up again.

I wish to show my gratitude for all of you who participated to "pin point" the likely source of this problem. I think that Rafael hit the nail on the head.

If the anomaly (lies) show up again I will consider sending the transmitter back for them to have a look. A problem might exist if the supplier does not see the problem at his location.

That is of couse MY problem.

Thank you to all of you.

Zor

Zor

Hi Guys,

A new development this morning.

Before breakfast I turn the system ON. Got two steady leds on receivers but NO servo response .

Look at the servo motion display on the Tx screen. The cursors are working and following the amount of stick motion. The servo on the table are NOT working.

Another look at the Tx screen. The cusors are following the stick motions.
Servos on the table are NOT moving.

Giggle the connectors to the receiver while the system is still ON.
While doing that I think "all connectors cannot be all missing all at the same time".
All servos are still DEAD.

Turn the system OFF. Wait a minute and thinking.

Turn the system back on. Everything is working fine. All servos moving and following the stick motions including in combinations (combination meaning two or more servos commanded simultaneously).

Trying to analyze the observations
The Tx display is and was showing the servo motions but the servos were NOT moving.
That seem to exonorate the transmitter

Could it be a binding problem? but the two leds on the receivers were steady on and bright.

Pehaps no power voltage to the servos ? Voltage had to be ON in the receivers for the leds to be ON.
Is one of the conductors feeding the servo power OPENEDin the receiver ?
Something to check when the servos again fail to work (red and brown wires).

Something I did not thnk of yet ___ I will have the oscilloscope ready to see if I can see the signal on the orange wire at the servo connectors.

NOTE: The signal cannot be a common connection that all fail at the same time since the signal commands each servo individually.

It would be an interesting situation to find that theTX screen display shows the servos positions as moving (while physically theyare NOT) and at the same time have power voltage to the servos (I can check that using a servo extension thus being able to use the scope or voltmeter). Such a situation would indicate a problem in the main receiver decoder.

Note : Both Tx and Rx were on battery charge for 6 boursyesterday evening to make sure they were not getting weak. measured his morning __Rx 5.49 volts __Tx 11.10 volts.

Let me go to the table and turn the system ON again.
The system came on fine and all working.
Off again and back ON.
It is working fine.

More later as I will be turning this system ON every half hour today and leave it ON for five or ten minutes each time. A sort of temperature cycling.

Wishing all a great day.

Zor

BarracudaHockey

My Feedback: (11)

Hold the transmitter 1m away from the receiver when they are linking.


EDIT: About the blinking lights...

If the reciever lights are slow flashing you have had a power interuption (the fast flash is with the bind plug installed)

You say "not all of them flash" and thats true, there's 3 different firmware versions running around.

Turn on the system and ensure its linked. Turn off the receiever and turn it back on.
1. Oldest - Reconnect occurs in 3 seconds, lights come on solid
2 First revision - Reconect occurs nearly instantly, lights come on solid
3 Newest - Reconnect occurs nearly instantly, lights flash.

Zor

Good afternoon BaracudaHockey and everyone.

I activated the system four times since 9 o'clock this morning.
There was no failures.
It is impossible to track down a problem when it is not there.

It is all above in the quote in red.

Have a nice day and enjoy,

Zor

BarracudaHockey

My Feedback: (11)

Just a note to say that turning off the transmitter doesn't produce flashing lights, just the receiver.

It sounds to me like you have the latest firmware.

If the transmitter is too close during linking OR of there's a lot of metal around such as a metal workbench, shelving, pickup truck bed, etc that will cause either swamping or reflections that won't let the system link properly.

Zor

All this is a fascinating part of what we are playing with.
The learning process is always the difficult part due to the difficulty of getting information.

Thanks again for passing along some of your experience and knowledge.
I just wonder how you got to your level.

Zor

Zor

Hello again to all following this thread,

I turned the system ON again may be about 10 times this afternoon.
No failure ___everything normal.

My curiosity (that will kill me . . . LOL) brought the old oscilloscope back to the lab (dining room table).

I found a servo extension that became plugged into the receiver throttle channel.
I turned the system ON and checked the voltage; read 5.22 volts.

I checked the oscilloscope setting using that 5.22 volts on the brown and red wires on that extension cable. It showed the DC and was adjusted (gain wise) to have 10 volts DC at near the top of the screen. Actually at the higher mainhorizontal line of the graticule in front of the screen.

Now what can I see if I look at the signal wire (the orange one).

Note that there is no servo connected to this extension cable and I used the throttle channel of the receiver because I can leave it in any position.

Well ... well ... what have I got here.? Some vertical deflection. all positive.
I remember that the common here is the negative.

The pulses are just about 3.5 to 4.0 volts amplitude.
I see two pulses after injecting a bit of positive synchronizing signal.
I look at the sweep speed which is on a range of 30 to 300 hertz. It appears to be just about45 hertz checking agains a 60 hertz wave (picked up from the line frequency).

So two pulses would re-occur every 1 / 45 = 0.022222 seconds. Well close to make sense fo a 22 milisecond frame.

Now what happens if I move that throttle stick to full throttle.
Ah! Ah! it just about double in width.

I play with that for a little while.

I now assume that the space between the pulses would be occupied by the six other channels.
It just look like they would fit nicely in between these throttle pulses.
-
CAn I now assume that the the receiver is sending in sequence to the 7 channels one pulse at a time that varies in width (1 ms to 2 ms) ___ may be more like 1.3 ms to 1.7 ms (ms are miliseconds); and does that just about every 1 / 45 of a second. One divided by 45 gives is .02222 second or the time of a frame. A frame being a complete set of pulses to all 7 channels.
Each servo would receive 45 pulses per second.

Am I making any progress ? Am I on the right track ?
Perhaps all this info is on the internet somewhere but where ?

Attached pictures quite clearly show the width of the pulses just about doubling from min to max throttle stick on the Xmtr.

Good night to all.at near 11:00 PM.here.

Zor