The signal strength of bluetooth is very weak

I am repairing a Nintendo Switch with a very weak Bluetooth signal output.
The controller will not be recognized unless it is about 1cm close to the Nintendo Switch.

I connected another antenna wire, but it doesn’t fix.
Also, I replaced BCM4356 with reballing, but it doesn’t fix.
I also tried replacing the Crystal oscillator near the IC chip, but it doesn’t fix.
(Please refer to the pic.)

Any other ideas?

I’m having similar issues but mine is wifi. The wifi is weak or cannot find a signal at all. I was thinking of reflowing the bcm4365 but still hesitant. Where did you get the stencil for the chip?

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If you have a spare antenna I would cut it and expose the center conductor, connect it to the board and ensure you have continuity (this is simply to verify the issue is not with the connector board side, mishapen etc) to the component/s in the general area.

Now, the antenna go off to what looks like a precision resistor package, but it’s highly likely that’s not actually what this component is as I haven’t yet looked into them, but they’re a 6-pin package, white and black and have an “S” printed on them, it’s possible if this component was open or had failed in someway that this is your problem.

If you have a known good board, I would verify that this 6-pin package tests the same as that

I’ve never encountered a situation where a bad WIFI/BT IC would cause your symptoms, if it was a bad IC then it would either not work at all or you’d get the orange screen. The symtoms are more inline with not having the antenna connected

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Thank you for your advice.
And it worked!

I first tried replacing the 6pin package, but it didn’t work.
If you look closely at another donor board, the orientation of the “S” is different between the white antenna wire package and the black antenna wire package.
I thought it had polarity, and when I installed it as shown in the picture, it worked.

I don’t know if it’s really polarity… :sweat_smile:

Thank you again Severence!

How do you test the S chip? So, there are 2 chips so one is for bt and the other is for wifi? Maybe this is the reason my switch wifi is not working

These 6-pin packages are SMD filters. One is probably for 2.4GHz and the other 5GHz.

I don’t know how you’d properly test these (well, you’d need to hook them up to a vector network analyzer, but these devices are really expensive) but it would be nice to know a replacement part number so we wouldn’t have to pull them off of donor boards.

(I can’t edit my message anymore so I’ll have to do it like this) addition: I think it’s a filter because of the top_hires.jpg image on files_zzattack_org (can’t post links yet), but I don’t know how accurate it is.