Search results

Full BIOS with clean ME same problem. Booting into Windows tries to star but soon after I get Your PC ran into a problem and needs to restart....

Safe Mode same thing, gets stuck loading bar.

Clean board, already tried clean ME, different SSD with clean install of MacOS and the result is the same, Mac chimes, bar starts to load and sometimes it may get to the end but OS never loads, starting in recovery mode same thing. When staring in Verbose mode gets stuck in: " In memory Panic...

Thanks so much, there was a bad cap in PP3V3_S4 that was bringing the line down a bit, replaced it and done!

Doing that makes 5V_S5 and 3V3_S5 stable

As mentioned before for example PP5V_S5 goes from 5V down to 2.3V in about 1 second then repeats, other mentioned rails do the same but with different voltage, so basically the voltages dont restart they fluctuate up and down fast and continue to repeat constantly.

3V3_S5 and 3V3_SUS diode mode is on par with known good board. Replaced L7560, Q7560 and C7524, C7564, C7518 and C7588 also measured all test points around U7501 as well as all resistors, all measure fine too, but after all this I still get same behavior.

With R5551 removed and its pin 1 shorted to ground 3V3_S5 and 5V_S5 is still pulsing same as before

With a charged battery the Mac started up, this told me that one or more of the CD3215 was the problem, so I did more and more testing and found that one of the ports (The one used to restore) when plugging a USB Tester did not give me the 5V out, so I replaced it and boom! Mac working! Thanks...

With R7551 pin shorted to grown I get same pulsing, with both R7551 and R7552 PP5V stays steady but board does not boot and 3V3_S5 goes missing.

Checked the resistors on page 11 as well as coils and caps, all are fine. Put board on oven for 15 minutes and now it is working, maybe PCH is dying, lets see. Thanks!

For example PP5V_S5 goes from 5V down to 2.3V in about 1 second then repeats, other mentioned rails do the same but with different voltage. ALL_SYS_PWRGD is missing completely

I dont have a programmer for this ROM chip, I do have another one of this boards so I transplanted the ROM chip and did a restore and get the same error as before.

Sorry about that L7630, L7430, L7310 and L7320 are also pulsing, I don't know why I did not see that in the first place. CPU_VR_EN and CPU_VR_READY also pulses about every 4 seconds.

At the end I measured a lot of the related 5-20V circuits and all measured fine, the one sign that I could see was PPBUS at 12V even and not 12.6V. One thing I could see was that I2C_UPC_SCL and I2C_UPC_SDA was 1.2V but no data was going thru when looking with oscilloscope I did the same with a...

Missing L3095, Pulsing L7520, L7130, L7630, L7430 Steady L7560 U1950 Pins 7 & 3 pulsing. PLT_RESET_L 0V SMC bypass same thing

Board was repaired a few months ago with SMC replaced and some corrosion clean up, now is back. PPBUS 8.6V I get green then orange light on original charger. I can trace the fluctuations as early as SMC_PM_G2_EN this fluctuates around 1.1V to 1.8V. Diode reading in all related rails are ok and...

All SSD power rails are on par with working board as far as diode measurements, they are of course missing voltage.

Clean board, old but clean PPBUS: 8.58V 3V42: 3.4V VRTC_G3H: 3.3V 5V_S5: 5V 3V3_S5: 3.3V 3V3_S5: 3.3V Checked all coils for shorts and nothing

Only C7226 was affected by corrosion and was not shorted. Diode measurements are fine, low resistance CPU lines were measured in ohms and were also fine. Forgot to mention PPBUS is 12.2V