SBus adapter failed?

[Airbo]

Hello,

I connected a FrSky R8 pro receiver to a black Spirit unit using the Spirit SBus adapter cable (RUD). Input at Spirit was configured as Futaba SBus. BEC was connected directly to the Spirit unit (AUX).

No receiver signals could be seen in the configuration software. I switched to PWM, this worked. I checked SBUS output of receiver, also ok.

I observed that the SBus adapter was getting quite hot. Is this normal? Or is it damaged?

Thanks
Airbo

[ZeXx86]

Hello,

this is because you connected the adapter in a wrong way.
Then it can be damaged permanently.

Please check the manual which end should connect with receiver.

[Airbo]

Thanks for your quick reply.

I connected the short end to the receiver, and the long end to the unit - as described in the manual. And I checked it three times before switching on the unit.

Is there an easy way to check if the adapter is really damaged?

What else could lead to this behaviour?

Airbo

[ZeXx86]

Ah. Maybe only some other mechanical issue inside. But if it is new, then it was tested before shipping.
It should not make any heat in any case. This is very important.
Maybe other possibility is that connector is rotated by 180° in the port.

[ZeXx86]

Are you sure the cable is SBus Adapter and not FrSky integration cable? They are looking nearly identical, except FrSky cable has one red servo connector.

[Airbo]

Thanks again for your kind support.

Your manuals are very, very good, so I would exclude a connection error. Nevertheless errors happen.

I made some further tests: I connected only the SBus adapter cable to a power supply, only + and - 5V, nothing else. The SBus adapter again became hot, and it drew 90mA - only the cable! I then removed the heat shrinking tube and found out, that the A04G is the part that is hot. I could not discover any obvious fault (soldering, ...) on the PCB (refer to attached photo).

I will order a new cable - unfortunately its on backorder ...

Regards
Airbo

PS Just to ensure that I made no mistake: power was supplied via AUX (castle ESC with TelemCC). After encountering the problems, I tried it differently and connected the ESC directly to the receiver. I suppose both variants are ok?

[ZeXx86]

The cable itself can be repaired if you can ship it to us, likely for free whatever was reason.

Normally it shouldnt be a problem even if connected in a wrong way. Only if cable was rotated in the port it might cause damage.
So it is really strange. Yes, there should be almost zero current.

[Airbo]

Thanks a lot for your offer. If it does not last too long until the adapters are available again, I would prefer to wait - its winter anyway. And a new adapter doesn't cost so much.

[Airbo]

To close this issue: I installed a new SBus adapter, and now it works perfectly ! I am happy with this.

But: there are two new - small - issues ("sensor lost" in Castle telemetry, LUA problems with X-lite). I will address them in new threads.