Have a hard time to re-use my Spektrum AR636A and AR636B receivers

[long-love-rc]

Hi,

I am here to seek some advices on how to re-use my AR636A and AR636B receivers. Long story short:

1. the AR636A receiver was left from a crashed HH Conscendo glider

2. the AR636B receiver was left from a crashed HH AeroScout trainer.

3. I also have a MotionRC Shrike glider, I put on a Admiral receiver on it. However, I don't really like my experience with this Shrike. Although all reviews I saw from MotionRC saying it easy to fly, I just feel the opposite. I actually crashed my first Shrike, with same Admiral receiver. I bought the second one, put on the Admiral again.

Note, the Shrike has a Skywalker ESC. Which is rated at 30A. However, from the Skywalker manual, which said this ESC can only support 4 servos with 3S Lipo. This is one point worth noting because the Shrike has 6 servos. But this point may not have anything to do why AR receiver not working on Shrike.

4. I want to put on either AR636A or AR636B to see if I can get the Shrike fly better.

5. hook up the AR receivers, both of them, thru Spektrum programming cable to my home PC. I saw the AR receivers from the software, I downloaded the SAFE profile from HH, and installed them on the AR receivers.

6. I put on AR receiver to Shrike. I plug the throttle wire to the channel 1 of AR receiver. Also put on the BIND plug. Insert battery. Pressing BIND button while turning on my DX6, the transmitter reported the bind was successful.

7. Then I unplug the battery, turn off transmitter, unplud BING plug. Now I insert battery again, the AR receiver just has NO any LED light. Turn on radio, the receiver has no any response. Push up throttle, motor is not running(I have checked the throttle cut switch too. I tried all possible positions).

I am not sure why the AR receiver cannot function at all. So I search thru the collection of parts left from past crashes. I put the AR receiver back to the same ESC from the HH Conscendo and AeroScount. To my surprise, it is not working either.

I measured the voltages from the throttle wire leading from ESC on three cases, they all appear same, about 3.27V. Is this throttle voltage supposed to be 5V? Seems my assumption is not valid. I cannot believe all three ESCs are bad.

It looks more like the AR receivers are not correctly handled by me, or they cannot be reuse at all? I have read all stuff I can find online, but I am lost now...

Thank you for your valuable inputs!

[xviper]

I'm not an expert on the 636 although I have successfully re-programmed 2 of them. I've tried to re-program 2 others without success. The man who knows the most about these RXs is Hugh Weidman (that's his username) so I hope he sees this thread and give some input.
I think that some 636s may not be re-programmable, depending on what plane they originally came out of. Some need to be completely wiped clean using a certain procedure requiring a downloaded file from Spektrum. Trying to re-program certain ones can result in really messing them up. Some are even locked and can't be re-programmed at all. You may be able to salvage them and start all over again by wiping them clean. However, I've seen where after trying to re-program them, they will no longer even be recognized by the APP.
I don't believe 3.2v will support a RX properly. They need around 5.5 to 6v, maybe a bit more. Also, crashes can do weird and terrible things to a receiver and other electronics.

[long-love-rc]

Xviper, thanks a lot!

An update on the 3.2V thing. I just realized that I should measure the second pin of the throttle port too. It turns out the voltage between the first pin(white wire, should be the positive) and the second pin is about 5V. It looks like some thought of differential setup, while the third pin is ground.

Forgive me for missing this obvious point.

[xviper]

White wire is usually "signal". Middle (red) is hot (positive). The remaining one (black or brown) is ground (negative).

[long-love-rc]

White wire is usually "signal". Middle (red) is hot (positive). The remaining one (black or brown) is ground (negative).

You are right, Xviper. I measured the second pin and the third blown pin, it is 4.99V. Thank you for letting me know this.

So now the ESC is definitely good. After binding, the AR636A or B simply refuse to power up.

[long-love-rc]

Just an update, I found this discussion at https://www.modelflying.co.uk/forums....asp?th=127320, which seems very similar to the issue in my hands.

[xviper]

Just an update, I found this discussion at https://www.modelflying.co.uk/forums....asp?th=127320, which seems very similar to the issue in my hands.

Yes, it is similar, however, they don't seem to mention anything about wiping the RX clean. I found the procedure once by doing a Google search "wiping clean a Spektrum AR636". One of the returns pointed me to the Horizon or Spektrum site where they had a step by step procedure plus a downloadable file to do it.

[long-love-rc]

Xviper, what does exactly mean "wiping the RX clean"? I have used SPS to download some pre-configed SRM file to my old AR636. Actually I choose the same Conscendo profile. Does that account for wiping it clean?

[xviper]

Wiping it clean is to remove ALL programming from receiver that has a pre-existing program on it. There are lots of hidden files in a RX that you can't see or access through the APP. If you try to put an SRM file into it, all you're doing is to replace any existing file. You aren't touching any of the hidden files. It's those hidden files that is likely preventing you from doing a reprogram on certain RXs.

[long-love-rc]

If you mean to re-install the firmware on the receiver, I believer I have used SPS to install the latest version of firmware on it. So it looks like it is "flashed". But is it "clean"? I am not sure... Anyway, that seems all things I can do with SPS, update the firmware to certain version, and import/export certain config profile like for SAFE.

BTW, I also tried the method of powering up the AR636A from an independent power source. I use a four-AA batt pack, and connect the negative to the throttle port's negative, such that they share same negative. Then I cut off the throttle port's middle red wire, the positive, and instead hook up the battery pack's positive. Still, same thing. The receiver can be bound. But after binding, next time when it get power and it still have no response.

[long-love-rc]

One more update:

I experimented with flashing the receiver with firmware 1.43. All my previous attempts were with firmware 2.30. With FW 1.43, the receiver now can be powered up by the ESC. And seems it is issuing valid control signals. The propeller rotates with throttle stick input.

I got this FW idea from https://www.modelflying.co.uk/forums....asp?th=114837.

FW 1.43 doesn't have SAFE. It does look like the SAFE thing is preventing the receiver to be properly powered up.

I then open SPS software, to see if I can import SAFE profile downloaded from HH. No luck here the software seems not able to do it.