820-01326: PBUS issues


New member

A new contender. 5v and ~30mA on the charger. PBUS is pulsing regularly at about 1hz. Sounds like a short somewhere? PP1V8_SLPS2R is trying to turn on but failing (only going up to about 0.1V it looks like). The rail is about 2ohms to ground. Is this too low? Injected a bit of current but T2 is the only thing that got warm.

PP3V3_G3H_T is 3.3V and so is PP3V3_G3H_RTC.

History: 2 probe points at T2 ROM were ripped off the board (SOCROM_CLK and SOCROM_MOSI). Soldered 2 wires for them directly to the resistors at T2.


New member
More info: Diode reading of PP1V8_SLPS2R is 0.010v or less. But it jumps around a bit. That's unfortunate because only T2 got warm when I injected current. Maybe some crud under it? I hate this T2 bs.


Staff member
Such low value is not good; very likely bad T2.
Nothing to lose heating it with quality flux; just try to burn eventually accumulated crap.