LEDs stopped working (fixed)

I’m not sure how i did it but i managed to kill all the LEDs on my phone :crying_cat_face:

trying to fiure out where the problem is, I don’t find any voltage on the VLED line. like if i go into the flashlight app & turn it on, I dont read any voltage at all on VLED

From what i see on the schematic it looks like VLED comes from U$10G$2 and Q2.2A. can anyone tell me where those two parts are on the (4G) main board?

Also - while hunting for those parts I noticed Q2.5 is missing on my board. it’s near one of the mounting holes for the LCD (the lower right hole) and i have a bad feeling i may have knocked it off while tightening the nut. does anyone know what Q2.5 did?

or is q2.5 on the physical board q2.2a on the schematics? maybe that’s why my LEDs aren’t working but nothing else seems broken?


ok i should have dug deeper before posting that but heres what i found after following the traces on the board

q2.2a on the schematics is q2.5 on the board
u$10G$2 on the schematics is u$20 on the board

makes it hard to debug & mess with hardware when the schematics dont match the product


so as a bodge solution i just jumped VSIM straight to VLED and now the LEDs work again

I get that the idea was to control power to the LEDs with SIM_DTR but as long as the LEDs arent actually lit up i’m sure their power draw is negligible so it shouldn’t matter a whole lot

its probably not a great solution if using the SIM7600 while the LEDs are on? maybe thats why VLED was switched? idk.

point is i got blinky lights again

The DTR pin needs to turn off the LEDs when the phone is in sleep mode because of a current leakage that we didn’t know how else to fix.

We’ll look into fixing the schematics in the coming months, thanks for pointing that out.

Ah, thanks for explaining about the current leak in sleep mode!

I’ll keep a closer look on the battery status to see if my fix has resulted in a faster battery drain.