Left Joycon Rail Not Recognized

I’ve been reading through posts on here and other places all day but can’t seem to find much information on the problem I’m having. I apologize if I’ve just missed it somewhere. Hoping someone might be able to point me in the right direction.

I bought another console on eBay in hopes it would be a fairly easy fix. The seller said that the left joycon rail didn’t work and you can’t get past the initial setup screen. I’ve replaced with known working rails from other units, and tried several different joycons, but nothing seems to work. The right joycon connects no problem, and the fan does seem to be working (I read that they are linked). Several people on reddit mentioned initializing the console, but that doesn’t work either.

The connector looks fine. I’ve tested for shorts and compared that to a working unit and can’t seem to find any. Could it still be associated with the fan even though that’s working?

Any help would be greatly appreciated :slight_smile:

1 Like

I replaced the PU chip on the back from a donor board…no change :roll_eyes:

Any other ideas?

I have this problem and cannot find any records of a solution, either. The Joy Con works on other consoles, and we have replaced the rail that is attached to the tablet; no change. The Joy Con is not detected at all. Any one come across information/resolution for this?

Have you or someone else changed the bq ic? sometimes the flux slides towards that connector and even if you measure from the outside with the multimeter, inside the connector there is no continuity with the flex cable, try the flex cable in a bit of ipa and inserting it and removing it a few times.

Last time I had this is was because when redoing the BQ area, one of the small chips on the back fell off and I had put it back on backwards.
This image:


of the other (right) side should help with working out which chips that connector leads too, though I ended up going through the images here to work it out:
http://balika011.hu/switch/erista/