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Actually VCCRTC is the PCH labelling, You are in the RTC portion of the PCH and the name of the power rail going into VCCRTC is PPVRTC_G3H. Yep I had the same issue a few weeks ago on exactly the same board. However, your resistance to ground on ppvrtc_g3h doesn't look like a short... On my...

2informaticos Yes! all secondary voltages are present, will check them again in case something changed. The only tricky one was the PP3V3_S4 being 2,5V instead of 3,3v.. Vcore is present at flat 1.8V no adaptation no red light on the mouse. JohnB8812 Thanks for the suggestion I've already...

So I tied together 3v3 from input to output, and the voltage doesn't drop. But the board is still cycling once and then stay on. Any idea? Thanks

Yes, absolutely correct level at the inputs, PP3V3_S5 and S4_PWR_EN are both 3,4V. This is why I conclude for bad chip but when replaced same thing... I compared diode mode and it's the same with good board. Thanks for the suggestion, iI will see what happen with bypassed 3v3 on in/out. I will...

Ok I just tested with another 820-00165 and in fact it doesn't rtc cycles like 820-3435/37. So my issue is: 1)PP3v3_s4 low 2,5V 2)It cycles once (i mean fan is on then off then on and stay on). Not sure if 1) and 2) are related I am more concerned by 2). Checked all 22 resistors and traces for...

Hi all, This is water damaged board. Initially no Magsafe light, shorted pp3v42_g3h in SMC. Replaced and we are back with green/orange light. After Magsafe light there was no fan spin and no PM_SLP_S4_l, PMSYSRST_L was stuck at 0.50V but no short. Decided it was time for a good bath, after...

Ok thanks I will report back!

Just in case, does apple logo takes time to appear? in this case it could need only a PRAM so it boots by default to internal hard disk. If you boot from external usb HDD, system will first try to look for an os on usb. You can also go in the boot menu and select your HDD even if it's the only...

Hello there, 820-3023-A, fan spins, no chime, directly white screen but no image, red light on mouse and cpu gets warm. No liquid at all, no reaction to PRAM with internal keyboard and external usb keyboard (with the internel disconnected). Unfortunately i don't have an identical donnour board...

Water damaged, no corrosion at all, battery shot. Someone worked on it previously for data recovery. Client claims it's not powering on. I/O cable broken at one end... keyboard backlight on the logic board (J4915) shot/burned. Connector on the keyboard backlight sheet also burned...

Ok you seem to have a break in the trace between pin 1 of R9731 and pin 1-2-5-6 of Q9706, so Double check before and run a wire If no continuity, after that you should get around 3V at pin 2 of R9731 it's bkl_en.

What voltage do you get at pin 2 of R9789? pin 1 of R9731? pin 2 of R9731? What resistance do you measure on R9731? ​​​​

Pin 3 should be way lower...something around 4V. Could you check continuity (diode mode) between pins 4 and 1-2-5-6? pins 3 and 4? EDIT: With no power applied of course.

Pin 1,2,5,6 are tied together they should measure the same, please check again voltage. Pin 4 is PPBUS_G3H witch you measured good at the fuse before. Look if you don't have now a short on PPBUS_G3H because of the soldering. You need to have ppbus_g3h 12.6V at pin 4 and Q9706 must open to let...

Oh sorry, scrap this, nothing to do with pp1v05_S0_ldo! Your problem is PP1V05_S0. Make sure by comparing with another 3115 there is no short on this rail. I can check resistance for you tomorrow. Q7630 is suspect. There is low value resistors in U7600 circuit, check them to make sur all ok.

You are in S0 state but missing PP1V05_S0. You will not have all_sys_pwrgd without It. Not sure but it looks like you are measuring resistance with power applied. I don't have a board in front of me to compare but I think 4,5 ohms on the missing rail is low. If no short look around U7780 see...

You could confirm for short directly on smc while removed by testing on gnd and pp3v42_g3h balls. So you don't need to reball and solder it back to finally confirm the short.

They seem close enough (5.3V-0.22pF), but are you sure this what's preventing usb from not working? They act like transient voltage suppressor/esd and rf interference stuff...look for further damage, do you get 5v on L4605 pin 2 and check continuity on L4600 filter.

Hi Titotinton, yes start checking power rails from S5. And see if any is missing or shorted, pulsing,...

Is the battery ok? I think these 820-4924 boards need a connected battery to start. You can disconnect internal keyboard and try external USB if you want to rule out bad kbd. 60w original magsafe charger? No short on power rails? Witch one is missing starting from S5.