Hi, I’m new to repair and I purchased a broken Switch OLED to try to fix it and learn something new. At first I got the OLED and while connecting the multimeter in the usb port it wasn’t turning on. I started to check for shorts in diode/continuity mode and I found out that one of the tree orrizontal capacitor near M92T was shorted. I replaced the IC and still the multimeter wasn’t turning on, but the short on the capacitor was gone. Than I started looking at the board and I’ve seen that two capacitors near the M92T were missing, so I did a search on this forum, found out the value and replaced them. The multimeter was finally turing on! I was so excited until I saw that the voltage was 9V but 0A… So I replaced the BQ and than the switch was drawing 0.128A at 9V and the voltage on the battery was finally increasing. I tried to connect it to display but still got no picture. Than I stopped working on it because and I checked on it the day after, and the multimeter was still turning on, but it was getting 9V and 0A still… So I tried to reposition the BQ and M92 but still got no Amp drawn. I checked the resistors near the BQ chip and they seemed fine, also the usb charging port seems ok.
Than casually I checked the capacitor under the cpu, and I found that many of them are shorted and also a cap near the IC on the top of the photo, the . I searched on the forum and found out some post telling that they might be low impedance cap and they might result as shorts, but I can’t understand how to tell if they are shorted or it is a false positive because on my multimeter the diode and continuity mode are on the same place. I don’t know how to proceed and would enjoy some advice from someone with more experience than me.
The caps with the yellow pin are the one that “beep” while in continuity mode and that I assumed they were shorted. Photo in the post after this one
When you say multimeter turned on etc, are you talking abiout a USB current meter?
Also, your IC installs look bad, you might wanna post better quality and closer photos of the ICs you’ve replaced or reworked so i can get a better look
Ty for you reply. This was a old photo, I reworked the MT and now it seems to me it has a good placement now. I also inspected the yellow marked cap and I found out that in diode mode I register 0,013V.
The bottom cap of the MAX770 showing as shorted in continuity mode, I think I should check for vsys and vbus on BQ to check if the MAX is shorted
Sorry still not looking good, can you give me clearer photos and closer up to any ICs you’ve reworked so i can verify. (good rule of thumb, if i can’t read the part numbers on said ICs in your photos, then i’m not gonna be able to see and help you with what i think is soldering issues)
Check resistance to ground in ohms, not diode mode or coninuity
WE CAN BARELY SEE YOUR MARKINGS
. The caps on the back of the CPU should have a super low resistance to ground and look short. Anything on the back of Big Silicone usually shows up that way.
Yeah sorry, it is night time and it is very difficult to make good enough quality photos, I will provide better one tomorrow with the microscope also
I checked all these caps and they have a resistance to ground of 18ohm on one side, so I think they are fine, the one under the Max IC results as shorted in continuity test but by measuring the resistance to ground I still get 18 ohm on the side with “70” marking, so I guess it may be fine (?)
@Severence Sorry, I missed this question, yes I have a usb-c current meter
I have trouble at making good photos with my s23plus, i’ll give you some but they don’t look really good, I’m sorry
Instead try putting the board on a window sil in daylight and take some photos with your phone, artifical light generally results in more noise. If you can try showing some pics of the IC’s youv’e reworked on edge too so i can get a better idea. (incl BQ IC etc)
I think you have soldering issues first and foremost. IC’s look off kilter and joints don’t look clean. After that, if still issues, I think you might have USB related issues and/or USB support circuitry issues. We’ll come back to that stuff after if a problem
The BQ chip is definetly off, I will wait for my order to arrive so I have the new solder wire with lead that should help me to rework the contact, I’m having troubles at melting the leaded free wire I actually have, I’ll wait for the order and try to resolder both the bq and mt and send some photos after I finished. Ty very much for the reply, I really appreciate your kindness and help, even if I’m new to soldering
Is it possible to use a tinned solder paste to tin the pads instead of the tin wire?
Sounds like a plan. If you find your iron is still struggling, you might find waving your hot air in the vicinity at approx 150c low to med air during might help you out while prepping the pads &/or post cleanup with iron.
No worries
You can do yeah but solder paste generally makes a bit more of a mess when used like this
I finally recieved the leaded solder and I did it! Thanks to your advices I reseated the BQ chip and the MT and now the console power on and it is fully functional!
Ty for giving me precious info on what to look at and how to proceed. Now I’m waiting to get a 36awg wire to repair a switch console that has a missing pad on the P13USB chip, hopefully I’ll get it to work.
Hi,
after some time of uses I got a really strange issue with the console: the console is not charging while connected to wall charger but, if I open DBI, run myp responder, plug into a computer it keeps connecting and disconnecting, but if I power off and power on the console from there, when turning on the console is fast charging fine… It seems to me like a SW issue because the console is charging fine with the procedure described, but it doesn’t with a wall charger… Do you have any idea? @Severence
sorry for the delay. I’d imagine based on the previous issues and current symptoms you still have install issues, either M92 / USB related. Feel free to post some images of your work again and I’ll take a look (on IC edge too if you can). Would also be worthwhile measuring resistance to destinations on a USBC breakout board too.
It’d be highly unlikely to be software related. Far more likely hardware issues causing an apparent software issue.
Hi,
No problem for the delay. Actually I bought some thinner probes for my multimiter and I’ve made readings for the cap near the M92. Some of them were reading as 0.0V, so I figured it out that something was wrong. I replaced the M92 again and now it is working fine. I checked the USB port for crossed pin but I am not seeing anything wrong, so I am hoping this M92 is better than the other one!
Ty as always for the precious help
