Hardware Switch voltages

[Kirgan]

Hello, I am new to this forum and don’t know if this is the place to ask this. I acquired a switch that wouldn’t charge or do anything. When plugged into the dock, I sometimes get a flashing green light. I originally thought I needed to replace the BQ24193 chip as I got 3.3 volts on pin five of the M92t63 IC. After replacing the BQ chip I no longer get 3.3v on pin five. I no longer get any relatively high voltage coming from the usb c port. The max I measure is around 10mV. I tried my charger with a friends switch and it said it was charging. Does the M92t63 IC somehow prevent higher voltages from coming out of the usb c charge port? Also what voltage should I expect when I measure from the charge fuse right above the usb c port? Thanks for any help

 

[Pintglass]

Does your switch now power on with a charged battery after you replaced bq24193

 

[Kirgan]

Unfortunately I don’t have another battery to test it with. Is that my only option?

 

[Pintglass]

Is your battery completely dead?
If its not completely dead you should have a voltage of around 4 volts on pad 1 in section L of the attached image.

 

[Kirgan]

I get a measurement of 0 on pad 1. With or without the charger

 

[Pintglass]

With the charger plugged in what do you get on pin 1 of bq24193

 

[Kirgan]

The pin I circled is pin 1 right?

 

[Pintglass]

Yes that’s pin 1

 

[Kirgan]

Can I measure it off the cap that’s connected to pin 1? Or does it need to be directly on pin one?

--------------------- MERGED ---------------------------

So off of both the cap and pin 1 I got 6mV

 

[Pintglass]

Have you got anything on the fuse in front of the USB port. Has the fuse got continuity across it

 

[Kirgan]

I get 5.3 mV on where the fuse used to be. I took it off because there was no continuity through it and bridged the two connections with some solder

 

[Pintglass]

Is that milli volts
Have you looked in the port under some form of magnification to see if the pins are all ok

 

[Kirgan]

Yeah it is milli volts. And yeah, everything looks good I think he port. I ordered more replacement ports in case I needed to replace the port. I plugged the charger into one of these ports and measured the voltage and I still got around 10mV

 

[Pintglass]

Have you tried rotating the direction of the charger when you insert it into the port, also check you get continuity from the port to the pad where the fuse should be.

 

[Kirgan]

I have. When I rotate it I start zero volts sometimes. And yes there is continuity

 

[mattytrog]

Suspect M92T36 power detector, faulty BQ24193 (yes, I`ve had faulty new ones) or PI3USB filter caps / decoupling caps.

 

[Pintglass]

Shouldn't he still show a voltage coming from the port even with a possible fault, he said he's tried a replacement port connected to the end of his charger but gets nothing on that.

 

[mattytrog]

Shouldn't he still show a voltage coming from the port even with a possible fault, he said he's tried a replacement port connected to the end of his charger but gets nothing on that.

Not read all the way through. He tried a new port without it being fitted to console, and he getting nothing on the pins?

Sounds like the SMPS has taken a dive. New adapter needed... Or test with a Samsuck charger.

 

[Kirgan]

I replaced the m92t36 and I managed to get some voltage (like 5ish volts, it fluctuated a bit +- 2v) where the fuse near the usb c port used to be. Unfortunately I didn’t notice the magic smoke leaving the new chip in time. I ended up frying the trace on the switch motherboard somehow for the vccn pin of the m92t36 ic so it’s no longer there.... quick follow up question, what is the SMPS you mentioned? Thanks for all your help

 

[The Real Jdbye]

I replaced the m92t36 and I managed to get some voltage (like 5ish volts, it fluctuated a bit +- 2v) where the fuse near the usb c port used to be. Unfortunately I didn’t notice the magic smoke leaving the new chip in time. I ended up frying the trace on the switch motherboard somehow for the vccn pin of the m92t36 ic so it’s no longer there.... quick follow up question, what is the SMPS you mentioned? Thanks for all your help

Supposedly if you check the capacitors around the chips they can tell you a lot.
If all of the capacitors are shorted on both sides (only one side should be going to ground) around a specific chip, that chip is probably faulty. There's no guarantee that a chip can't be faulty without displaying that specific behavior though. But at least if you find a bunch of shorted caps around one of the chips you know that chip is most likely the culprit.

 

[Pintglass]

I replaced the m92t36 and I managed to get some voltage (like 5ish volts, it fluctuated a bit +- 2v) where the fuse near the usb c port used to be. Unfortunately I didn’t notice the magic smoke leaving the new chip in time. I ended up frying the trace on the switch motherboard somehow for the vccn pin of the m92t36 ic so it’s no longer there.... quick follow up question, what is the SMPS you mentioned? Thanks for all your help

SMPS is the power adapter that comes with your switch

 

[mixelpixx]

I would:

Check the output on the power supply, correct output V / A?

At board, with supply connected, check one side of caps (other connected to ground) for voltage.

To check that a Cap has the correct capacitance, you would need to remove it from the board, and have a meter that can correctly test capacitors. These tantalum caps in the pic are filter caps, if you look around in pic, youll see where power comes in -- and an ic -- so those are all there to knock out noise @60hz. One side will connect to ground, one side to +source.

Cant test most components on board because you would need to know designated operating/in-circuit values. So you would need to remove any bricks to test, caps or resistors. Testing capacitors with a regular meter will always show an open on a capacitor if you check it for resistance -- those bricks only go bad when you heat them up and cook the ends off of them, or they physically crack/break.

You would then need to determine Res, and Cap of each component you remove. With components removed for testing, you can clean up pads on PWB and test for bad solder joints, damaged pads, etc.

As this is listed as water damage, remove PWB:

Clean area you believe was wet with 90%+ alcohol (70% is ok, but the other 30% is water..)
blow excess off with compressed air.
Preheat oven to near 100-125deg. May need to heat it to 200+ then turn off and insert board when oven reaches correct temp. you can just leave board in oven (on a cookie sheet an towel maybe) till its room temp.
Depends on how wet it got, but if it was a quick splash then this should dry everything, if you have ability 100deg for 24hrs is preferred.

hope this helps you, if not let me know i can try to help you revive the dead