I was trying to check for voltage on the c-port pins with the charger and battery connected with switch turn off. I honestly didn’t think nothing would happen and I don’t know why it was a good idea as I saw it in another discussion, but then I heard something pop when measuring with the black probe on ground and red probe on a c-port pin. All ribbon cables and connectors including the fan ribbon cables were disconnected, except the battery, charger and the one circled in red were connected.
please I don’t know if the battery popped or something else because the chips including the PI3USB don’t look burned. I tried turning it on and it won’t turn now after I assembled it.
I don’t know If I need to replace the battery or what happened.
I checked the voltage of the battery and it was 3.7V when plugged in so I think the battery is fine. Now I don’t know if a resistor or another thing popped. which component is the bad one. I which I could put pictures but I get “Sorry, you can’t embed media items in a post”.
This is how it was tested with only the battery plugged, charger plugged, and the red circle on picture( I think it is the speaker) plugged. Then I tested with the probes at the c-port pins and something popped, I don’t know what happened.
Hey Calvin, the fuse (over testpad 6) doesn’t work as it doesn’t beep on continuity mode on either side of the fuse and it has 1.5milliΩ on one side and 3.7milliΩ on the other. Should I replace it? I know the size of the fuse is (0402 3.5A 32V).
I checked for voltage with the battery plugged and no charger plugged, in the pin 9 and the other yellow markings you highlighted and in all I get milliV to 0V.
I am also going to change the Pi3USB as it has a short in the big capacitor above it, which originally had it before I made the short myself by passing the probes one to ground and the other to the c- port pins with the battery and charger plugged.(original problem before was that it was not docking to tv, everything else worked fine)
Giovani, check the fuse on continuity by red tip on one side of fuse a d black on the other side of fuse? It should beep then u have a good fuse if not then bad
It sounded like you have black in ground and red touching one side of fuse then the other side. This is wrong
Yes thank you, I messed that up, so in continuity mode it beeps when each probe on both sides. So the fuse isn’t bad aparently.
I think I also measured bad with checking the voltage in voltage (normal mode) and I got 0V.
Now I checked with (diode voltage mode) with black on ground and red probe on pin 9 of chip and the others marked in yellow and I got this
I would check in diode mode (No battery, no power supply, RED probe on ground, black probe on the pads) for correct values. Depending on your multimeter the values may have an offset. But “OL” means open line --> no connection and 0V means direct connection to ground.
I ordered a new pi3USB to replace it, as it also gives short in the capacitor of the pin6 of the M92T36, as shown in pic below. I’ve seen that it usually fixes that short from videos.
From Pin 21 (SBU1) and pin 22 (SBU2) through their chokes are each one line. Your reading should be the same between the pin at the pi3usb and its choke pin.
If the “oL” on SBU2 is correct, this should be the cause for no ouput to tv.
You measured three time “oL” at ground pins (light blue markings). Please check it again direct on the pads.
I would desolder the m92t36 and see if the short on the 3.3 V line (all .431 pads at the pi3usb) is gone. If not, I would desolder the pi3usb and check again.
Yes, sorry I need to buy some needle probes but now I corrected them including changed values in choke, blue marked areas and other OL’s. The OL in SBU2 and pin on pi3USB is true, as (switch doesn’t display when docked) but charges on dock.
I ordered m92T36 and pi3USB to see which one I have to change. Hopefully it also fixes the no power problem I made( I still don’t know what that audible click or pop was).
I will post results when I desolder the chips in that order and check for shorts
