Recent content by galvestonmac

Got the clock issue fixed but then suddenly now I have a short on PPBUS_G3H. It was measuring 2v at F7140. I was looking around for something that was getting hot but couldn't identify anything. I injected voltage to the PPBUS_G3H line and slowly added voltage up to 1v. The CPU was heating up...

Changed clock chip out and now I have 3.41v on U1900 pin 1. Now have .04v on U7501 PP5V_S5. I've already changed out the chip. Do you think that something else cooked it while I was messing around with U1900? Ugh

PP5V_S5 diode mode measured at C7505=.479Ohms PPVRTC_G3H diode mode measured at C1910=.472Ohms Looking for a replacement clock chip in my donor boards to replace this one with

I’ll check out the clock tomorrow and report findings. I will also measure in diode mode on 5V line.

Do you think that if I inject 5v on the PP5V_S5 line at maybe C7505 I'd have a better chance of finding the short? I also tried with the battery but there is no change. Looking for the short: Removed 4820-.75v Removed C4810-.82v Removed C7505-.81 Removed C7400-.81

More measurements: SMC PM G2 EN=3.42 at R5198 SMC_BC_OK=3.09v

OK. Thanks. Could very well be! I'll check it out!

I have an 820-00165 MacBook Air 2015 board liquid damaged with green light/no power/no fan. Damage was centralized on U7501. Via to C7500 to pin 23 on U7501 burned. Replaced U7501. Voltage at pin 14 on U7501 .75v before chip changed. No change in voltage after chip changed, still .75v Replaced...

Resistance to GND for PPVCORE measured at C1681 is 26.6 Ohms. Will check out U6100 closer

Thanks. I'll check PPVCORE again to verify. I believe that it was steady.

PPBUS_G3H=8.40v PPDCIN_G3H=17.8v PP3v42_G3H=3.42v PPRTC_G3H=3.42v PP5V_S5=5V PP5V_S0=4.6V TO .03V RANGING Removed and resoldered U6100

I've also checked out R5110, R5111, R5112, etc. R5121-R5128 and they all check out with correct readings. Steady 3.3v at R6101 even during power cycling.

On R7086 I get a steady 6.81v on pin 1. On pin 2 I get 0v. Resistor checks out as 330k with meter. Not sure what I should be getting at pin 2 for voltage.

Diode mode measurement PPVCORE_S0_CPU=.46 ohms PPVRTV_G3H=3.3V Nothing that I can see on JTAG. I put it in the ultrasonic tank and cleaned it thoroughly with alcohol and a toothbrush as well.

I have an 820-3023 with liquid damage that will not start up. Corrosion was found at U6100 and cleaned. Voltage at Y2705 is 1.14v when power cycles up. Green light on charger, PPBUS_G3H 8.6v When power is plugged in the fan spins for 1 second then stops then starts again 5 seconds later...