Search results

Got this one braindead; running fans, but nothing else. Reflashed BIOS with a clean one found on this forum (serial changed + checksum fixed) on a different chip and it came to life. Started a Big Sur install, crashed while loading the installer and now it's looping; fans spin for a while and it...

A customer sent this in with diodes D3300 and D3400 both shorting the PP20V line. I did the same repair 1,5 months ago on this machine. Suspecting a bad charger, any other things I should check?

* Crashes shortly after booting: black or garbled screen and no response * Everything seems fine till then * Logging looks normal * Removed a small bit of liquid damage between two of the unpopulated pads for U5450, looks clean otherwise.

OK, time to disappoint a customer then. Thanks for helping anyway (y)

No pulse at either PM_SLP_S4_L or PM_SLP_S5_L. PM_PWRBTN_L drops to .36V after triggering SMC_ONOFF_L and returns to 3V after.

In order of appearance: Yes, tested board alone PM_PWRBTN_L drops to .36V after triggering SMC_ONOFF_L Probably not, took the path of least resistance as I wasn't sure there were any 0 ohm resistors or 'switches' between these lines. I'm sure only having 5 of these 6 would cause some kind of...

No liquid damage, board in perfect condition. According to customer, this MacBook suddenly died on him. Measurements: PM_PWRBTN_L 3,3 PPBUS_G3H 12,6 PM_RSMRST_L 3,3 PPBUS_HS_CPU 12,6 PM_DSW_PWRGD 3,4 PPBUS_HS_GPU 12,6 RTC_RESET_L 3,1 PPBUS_HS_OTH5V 12,6 PCH_SRTCRST_L 3,1...

Changed the chips, but that did not bring much improvement. Gave up on this one because I didn't have much faith in it becoming a trust worthy board. Thanks for the help anyway.

PIN U2600 U2650 Known good 14 CRFILT 1.25V 1.27V 1.23 34 PLLFILT 2.91V 3.21V 1.18 ALL VDD 3.3 3.3V 3.3V CRYSTAL 0MHz / 0V 0MHz / 0V 24MHz / .9V PLLFILT voltage looks high, as this is connected to a 1.2V regulator. This also is a likely reason for the lack of freq/voltage on the...

Sorry, I meant to say U2600 and U2650. Visual inspection is easy BTW and one of my most successful tools in my tool bag. I wasn't suggesting they are working correctly, but merely that they have no burn marks and were not directly affected by the liquid. Anyway, testing webcam and bluetooth is...

* Liquid damaged board (mostly SMC area) * None of the USB ports are working, 5V present. * No keyboard/trackpad (likely USB related) * Both USB hubs (4600/4650) seem fine visually. * Working fine otherwise (limited testing w/o USB though) It seems to me that the USB link between PCH and these...

Reballed SMC, termination resistors are fine. Found R4902 and R2140 to be open circuit, replaced it seems to have improved the situation. Still need to do proper testing, but thought I'd let you know. Thanks so far!

All rails present, except for vcore and PP0V75_S0_DDRVTT (needs CPUIMVP_PGOOD). U7400 gets enable and power. ALL_SYS_PWRGD present PM_PCH_PWROK: present PM_PCH_SYS_PWROK: NOT present >> CPUIMVP_PGOOD NOT present History: * Milk damage * Mostly near SMC, but SMC was underfilled/glued...

Thanks, will try the tool once I get to it. It's my own laptop for a change, so it'll have to wait ;-)

I know these can have the CPU buck converter problem, but the error trace suggests the SSD (aftermarket with adapter, running flawlessly the past 2 years). panic(cpu 0 caller 0xffffff7f9d6c9231): nvme: "Fatal error occurred. CSTS=0xffffffff US[1]=0x0 US[0]=0x2e VID=0x1179 DID=0x115 . FW...

Yes, that's what I meant to say: changing U3100 fixed it. Strange one because all earlier problems had nothing to do with the cd3215s. Must have been some corrosion I missed or something.

Fixed it.

Any ideas how to attack this one? Seems to work ok, until it doesn't. Board looks clean. Considering a mem reflow.

Yes, it sweeps, not optional on mine. 1V1 missing on U3100, present on the other CD3215.

No, cd3215 area looked clean before ultrasonic. All ports act the same.