TLDR: See the pics for the shorts I found while troubleshooting a switch that won’t turn on or charge. Let me know what you think the best way to fix this thing is. THANK YOU!!!
I’ve got a V1 Unpatched Switch that I bought on Fbook Marketplace. The seller told me that it would occasionally power on. I bought it because it was unpatched and I figured I could have a go at fixing it. It never powered on. I took it to a repair shop and they repaired it. They told me that the OEM Dock that I got with it was bad and not to use it. I took it home, and listened to bad internet advice and used the dock. The switch printed an error message on the screen which I didn’t see, it powered down, and has been in a drawer ever since. I recently got a simple hobby scope, and dug this guy out of storage.
After poking around I’ve removed the motherboard and tested the usual suspects. I started with the M32 and found one cap shorted. It’s marked in red here:
(I’m a new user and I can’t post my pics )
So I flipped the board and tested the caps and filters there. Here’s a marked up photo
(I’m a new user and I can’t post my pics )
I found the top cap (marked in red) shorted. I also noticed that the first filter (marked in blue) has continuity across the left pins (marked in yellow) but not the right (marked in purple). There’s no continuity across (horizontally) the pins.
I decided to check the BQ circuit as well.
(I’m a new user and I can’t post my pics )
There were no shorts on the caps, but one cap (marked in red) didn’t have continuity to ground.
I’m assuming that I need to replace, at minimum, the P13USB chip. But I’m concerned about that filter. I saw a video where somebody showed continuity across each set of pins, vertically. I don’t have that. Further, I think the cap on the BQ circuit should be grounded and it isn’t. I read that’s a sign that cap might be bad.
I’m turning to you guys as the experts to help me troubleshoot this. I’m going to need to buy a hot air station and components. I don’t have them laying around, but I figured that this time, it would likely be cheaper for me to buy the equipment and do the work, and in the end I’ll have the equipment.
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to 1. This cap is usualy short if pi3usb is defect
to 2. I guess pi3usb is defect too and is shorting the power line to gnd, beside the filter with missing continuity
I did a little more reading. It looks like the P13USB is for video out over usb. So removing the chip just means that the unit won’t dock anymore, right? I’m very okay with this.
If you want to troubleshoot further, the next step would be removing the pi3usb and see if the short is gone. Without this ic there is no signal output to the dock.
My advice: If you don’t have experience with micro soldering and want to use the Switch after a repair, look for a technican, who can replace/remove the ic (and the filter).
I don’t have microsoldering experience but I’m interested in it as a hobby. I like building these skills. It’s fun.
I’ve got a dead switch lite which I assume doesn’t have this chip, but it has others. I would be game to practice on it and then try to remove the P13USB.
I’d like the switch to work afterwards, but I have another which is my daily driver, a spare that I recently mod chopped, and two more Lites which are due for modchippjng.
I’ll need a heat gun. I’ll completely remove the motherboard. What other pointers should I consider?
That is a good idea to gether some experience on a defective board. The m92 and the bq on a Switch lite are also qfn-ics (the same pad layout). If you are able to take them off and put them back again, so that all pins are making contact with their pads, without shoving other surounding components around, I would try the pi3usb.
You can further narrow down the cause / culprit of your 3V3PDR rail short by measuring at a few of it’s other locations prior and seeing which area represents the lowest resistance to ground thus pointing to the most likely candidate, for example at pin 6 (or is it pin 5 I forget) of the M92, the large caps by the ENXX IC, at the EMMC etc etc, If your reading was lowest at the M92 IC then you can safely say it’s likely the M92 IC at fault or at that cap by PI3 IC then you can safely say it’s that IC most likely at fault and so on and so forth… this just saves you randonly pulling off chips which may or not be the cause and takes about 30 seconds to do with a meter.
And of course, check your USB port too for bent pins incase that was the original cause of this fault.
You mention putting the chips back. Am I right in believing that if the P13 is at fault and I remove it, that I could leave it off permanently and have a switch that won’t dock? Will it still charge?
I don’t need this one to dock and I’m wondering if there’s something else that’s caused it to die twice now when docking. I’m sure that the dock I used is a problem, but to be in the safe side, maybe this can just live out it’s life without docking capabilities.
Assuming it is what is responsible for the short on your 3V3PDR.
Correct but this is providing that you have no other issues, for example a damaged USB port could cause you other problems depending (even if not now but later)
Can only really be the USB port at fault or the docks (USB port). that’s assuming the culprit is the PI3 or M92 ICs
In regards to your short on 3V3PDR, I’m unsure if it’s the PI3 IC responsible given that it looks as though somebody has already replaced it based on your image (at least afaict), though the resistance checks I mentioned earlier should rule this out . If it’s a bad USB port on your dock or the one on the consoles mainboard it could just as likely be the M92 IC at fault too.
It’s very possible that it was replaced as I did have this repaired at a shop.
What makes you think it was replaced. When I inspected the board I was trying to figure out what the tech did but I couldn’t see obvious (to me) signs.
I think i can see flux residue on the board (though could just be a trick of the light) and solder around the PI3 IC doesn’t look factory together with a couple of areas where the solder mask has been over exposed (usually as a result of someone being a touch heavy handed with their iron or wick if appicable)
On the plus side, if it turns out to be the PI3 at fault and if it has been replaced before, you’ll at least have an easier time getting it off as in all likelihood the tech used leaded solder
)
. If it’s a bad USB port on your dock or the one on the consoles mainboard it could just as likely be the M92 IC at fault too.