Red LED always on - is it dead?

Hardware RFM69Pi
1

Hi,
I was building an RMF69Pi onto my mini motherboard and testing it when I may have touched another mini board against the power connectors possibly causing a very breif short although I didn’t touch the actual RMF69Pi.
However, the RED led is now permantly on. A few years ago I accidently connected an RFM69Pi to the Pi whilst it was on. This also caused the RED led to stay permantly on.

I seem to be able to reload my software but once it runs the red led still stays on.

I think the RFM69 boad has blown. Has anyone else had a similar issue? If it somehow got a 5V surge could this blow the rmf69 but leave the main board intact?

Mike

2

That looks to be a serious possibility. The LED is used to indicate activity - looking at the code, I see it’s lit right at the beginning, at startup, and for one second after the startup code completes; and when sending data.

I suspect the startup code is freezing at some point, and that (on the emonTx - same radio and processor of the same family) is almost always an indication of a problem with the radio. Certainly, the RFM69 is only good to 3.9 V, it cannot accept 5 V at all, whereas the processor is good to 6 V.

If you have the skills to remove the RFM69CW from the board, you could try replacing just the radio module.

3

Thanks, I’ve already ordered some from ebay but comming from China. I have removed it but some of the pads seem to have come away. Is that a problem? Can I solder to the dark patch?

4

If you don’t have the right equipment, that’s always a danger. And likely to be a big problem, and no, you can only solder to copper, not to a mixture of glue and burned p.c.b. You can buy a radio-less RFM69Pi from the shop.

Not all the pads are used, if it’s an unused pad, forget it. If not, with some very fine wire you might just be able to wire from the RFM to somewhere else on the board. The p.c.b. is on Github under RFM2Pi.

6

Thanks, yes when I looked in the light of day I relaised I had remove the copper base. Oh well. I need to make two connections plus earth. I think a thin wire might save me. Worth a try now I’ve ordered some RFM69 boards. Nothing to loose. Thanks for the help. I’ll give an update in a few weeks when they arrive.