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PMU_ONOFF_L is 3.37V PM_RSMRST_L and PM_PWRBTN_L are both 0V with a 100mV pulse (over 0.2 seconds) when connecting adapter. U4760 PP3V3_S5 = 0V PP1V8_SLP2SR = 1.8V SMC_SYSRST_L = 0V SMC_PCH_SYS_PWROK = 0V SMC_PCH_PWROK = 0V SMC_RSMRST_L = 0V

Yup, getting 12.3V at F7000

U6940 1 PP3V3_G3H_RTC_X = 3.3V 3 PMU_ONOFF_L = 3.3V 4 PMU_RSLOC_RST_L = 3.3V 10 CHGR_RST_OM_R = 0V (no short to gnd)

Customer says this machine stopped working from one day to the next. I went over the board and all connectors and found no signs of liquid or other damage. All four ports sit at 5.18V with a 60mA current draw. PP3V3_G3H_RTC_X is at 3.3V PP20V not shorted to ground. I understand what to do when...

I checked nearly all pins in diode mode (some I couldnt reach a measuring point under a shield by U2800 or by J3300) and only this stood out: pin 62 U3100&3200: 0.951 vs 0.969 on working board pin 84 U3100: 0.985 vs 0.967 on working board pin 94 U3100: 0.990 vs 0.968 on working board pin 95...

Board came in clean looking, no corrosion spotted anywhere so far. It drew about 2,5 amps at ~4 volts and didnt switch to 20V. PPBUS_G3H and PP20V_USBC_XB_VBUS_F were shorted to GND Q3100 had an internal short, bridging PPDCIN and PP20VB. replaced it. Q3200 replaced just in case. pads for both...

Well, that sucks. Can you think of a way to make it think the internal display is actually the external one?

Ah, image before BL. Didnt know that, thanks. Measured (with display attached): PP3V3_S0SW_LCD 3,3V PP5V_S0SW_LCD 5,1V DP_INT_HPD 3,3V

You're right, me and others.. I tend to forget how often I end up fixing things through this forum without having to open a new thread.

This one came in with liquid damage that was repaired by someone else. U2890 and some components around it were replaced, flux was still on there. This board powers up fine and shows an image on external display, but not on the built-in screen. No corrosion around J8500 or the board to board...

Took a while, had to wait for new donor boards. SMC replaced, got quarter fan spin. Turns out I ended up missing PP5V_S0. After fixing that, I found out that CPUVCORE was short to ground inside the CPU. Way too much wasted time, shouldve checked for shorts much earlier :( Oh well.

Ah, so PM_DSW_PWRGD needs to come out of the SMC if it gets S5_PWRGD as an input. Will report back when SMC is done..

When triggering SMC_ONOFF_L, PM_PWRBTN_L is pulled down to ~350mV 3V3_S5 is ok S5_PWRGD ok PCH_DSWVRMEN 3.2V PM_DSW_PWRGD missing PPVRTC_G3H 3,3V RTC_RESET_L 3,3V PCH_SRTCRST_L 3,3V PCH_CLK32K_RTCX1 0,4V Last one I assume should be 3.3V. I checked U1900 and...

I can't speak for others, but; because I often enough don't fully understand the circuitry, but try to find out which inputs or outputs are missing and lead that back to their sources. If I cant figure out what exactly is going on, I have to experiment or post here for advice. I check for...

All resistors measured (had to lift some to make sure), all match the schematic in value. I've lifted Q7630 to make sure theres nothing wrong underneath - no corrosion or anything these. Powered machine on without Q7630 on there, but still got 0V on P1V05S0_DRVH. Caps all looking fine. See...

This board has past liquid damage, has been repaired by someone else and now got liquid damaged again, again been to someone else and now ended up with me after they gave up. About half the IC's on the board have flux there, so either replaced or just reflowed/retouched. To make things worse, a...

Alright, too bad :(

Dove into this board again today. Recap; 1. PP5V_S5 was shorted to GND through C8270. I replaced C8270 and U7650. Machine worked, then stopped. 2. PM_SLP_S5_L was mostly 0V but had spikes. P5VP3V3_VREF2, S5_PWR_EN, P3V3_S5_EN and S5_PWRGD all had block shaped waves on scope. I found out that...

Frustrating board.. I found out why 5V_S4 was short to GND; Q7660 was faulty. internal short, probably. I replaced it, Short gone, but no voltage on the rail still. Fed the rail 5V through my lab supply, no issues there. Replaced U7650 again to rule that out. Got 8.7V on 5V_S4. Q7660 burnt up...

I'll think about it, but not in such a hurry that I'll get one just for this repair. I'll lift stuff off the board for this rail and see where that gets me.