Hacking Left joycon randomly stopped working

[iamjoysus]

I installed a HWfly chip in my Mariko switch some time ago.
I went through the tutorials and installed Hetake, Atmosphere CFW, backed up the eMMC and set up emuMMC. After this all worked perfectly... that is until some day I started getting random disconnections on my left joycon when playing attached. It forced me to unplug the joycons and play wirelessly. After some attempts, plugging it back again worked until it failed again after a while.
One day the left joycon was not recognized anymore, and I could only play wirelessly. However, after I left the switch off for some time with the joycons attached, it was suddenly recognized again when I turned it on. This is consistent with some similar issues I have read, but I can´t reproduce this again.
As of this time, it does not work anymore. And I can´t even connect any joycon wirelessly, not even the right one which is actually detected when attached. I have tried many things:

• Tried other controllers to make sure is not the joycon itself what's broken
• Replaced they left rail in the switch in case I damaged it somehow
• I have tried using a new SD card going through the CFW installation
• I have also tried all the unsyncing stuff I have read in the forum, but the only controllers that are detected are the right ones and only when attached

The only thing I'm able to reproduce is this:

• While on Hetake, I press reload with the affected joycon unplugged. Once it reboots, I connect the left joycon and it actually works for a short time (allows me to move the cursor for instance). If I'm fast enough I can even dump the joycon info and both are detected

To me it looks like it is not a hardware problem, but I have no idea how to fix this. The only 'weird' thing I did after everything was working properly was to update the OFW from xx.2 to xx.3, but the errors did not come inmediately so I don't think that was the root cause.

I'll be happy to hear any ideas, it is giving me headaches

 

[Hassal]

Check the connectors where the ribbon latches to the motherboard.

 

[iamjoysus]

Check the connectors where the ribbon latches to the motherboard.

I have done that just now and cleaned the connector, but it does not look like there is damage and the cable is well connected. Besides, the joycon still works for some time when I’m in the bootloader and I can reproduce that as I described in the OP. To me it seems like a software error, but I have no idea why.

 

[terminalshort]

I am the OP, forgot the account password so answering with a new one...

In case anyone stumbles with this, the problem was solved.
It was a hardware issue after all: turns out the new rail replacement I got was also faulty. The confidence I had in the replacement being OK made me think of all kind of crazy wrong theories...

The reason the joycon was working wirelessly at first and then stopped was because of the joycon battery, which had drained. The faulty rail prevented the joycon even from charging.

So lesson learnt: always double check replacement parts.