I am new on that board, not an expert but as a hobby I am trying to improve my repait skills.
I need some help with a defect switch where I cannot find the problem.
I purchased a faulty switch - the description was that someone sat on the switch after that the switch does not wok any longer - not sure if this was the true story.
When I put in a USB cable there is no loading and the USB charger show 0.00A for loading (no slow charge at all)
I put in a known good battery - but no change - no charging, no booting etc,
I checked for shorts on the M92T36, P13USB, BQ24193, Coil, Fuse and have not seen any shorts if I have done it the right way…
I put in a USB cable an measured the fuse, where I can see a 5,13V - so interpreted that the USB-C port should work in principal.
Now I am running out of ideas what I can do - I attached some pics - maybe there are some tips / helping hand you can provide ?
Measure them when battery and charger Re disconnected. Put multimeter into diode mode not voltage mode. Red prob to ground, black prob to each test point, normal reading should be around 0.7~0.8(700~800)
Hi, thanks again for helping me withe the correct measurement!
I checked this again with the multimeter and looks like normal reading - 0.854 / 0.859 I received from d+/d-
I just got a switch that’s in the same boat. No short anywhere. Normal readings in Diode mode with the exception on one big cap on left of m92t36( suppose to read 0.489 but I’m getting well above 2.0 plus. Maybe I need to do another m92 chip. Ordering a new one
Just update on my situation, hope yours is similar. PIN number 5 on M92p36 was reading 2.6 plus in diode mode. I connected the power wire to see if any power is leaving m92 chip with cap at bottom right of m92 chip and it was not.
Instead of waiting for a new chip I decided to take the chip off and ad more sodder on pad , put it back in and touch up all the points again.
Pin 5 now has the correct reading. Ran and power test and it boots up and charging now.
This are good news - at least that there is some hope that this can be fixed.
I guess with my switch there could be a problem with the M92T36 or with the BQ241943 - in the area of BQ241943 there is some damage which could come from the “sitting on the switch” problem.
Unfortunately I haven’t found any indication if this is right or wrong or if this can be checked upfront.
On the M92T36 I could not found shorts, but I tried to measure the pins and in the red marked area there are some pins connected to ground - but not sure if this is normal.
If there a way to check deeper if some of these chips are faulty (before trying to replace them?)
Well, I tried to replace the M92T36 chip to check if this might help - but in the end does not work well and I blowed a few small components away - which I cannot resolder easily.
As I am not sure that this was the problem I will give up and will make it better next time (hopefully).
My friend you have to check charging port m92 and BQ if you’re missing filters or cap will not power I can fix it for you if you want I will just change the parts fee no labor fee and a return shipping label
