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820-02098 M1 Pro 14" PPBUS partial short
Hi,
board came with no signs of life whatsoever, taking only 5V.. measured PPBUS and it was partially shorted (I kinda know this is not an easy one when it's a partial short) around 9 ohms in resistance and 0.012 in diode mode.
Injected 2 volts since 1v was not enough and my initial suspicion was correct it was the haunted TPS62180.. and on board it looked little discolored to my on the visual inspection..
Removed and replaced successfully now left ports take 20V for 2 seconds then switch to 5v and cycle.. on the right side it does not even power on the amp meter.....
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820-02020 A2338 Restore/Revive Failed
[B]A2338[/B] - Pristine condition.. I took out of the board and inspected it.. nothing.. as if the computer is barely used even.
Anyway, customer said they tried erasing/formatting it and it got stuck on Apple logo preventing to go further.. I asked them why they tried to erase it from the first place? They said it turned off randomly once.. then they erased it and it worked out for a few days then it shut off again..
I put the computer in DFU; I downloaded the latest Ventura IPSW and restored it.. during the "Installing.." it restarts then it shows the...Last edited by iMuhtaseb; 09-11-2023, 08:59 AM.
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820-00244 bios
Hi i have a A1534 with bad BIOS chip and i cannot read off it.
Can somebody send me a clean BIOS file for it?
SN: C02SD02FH3R6
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Re: Water damaged M1 MacBook Pro (820-02020)
FF200 fuse removed and I soldered FF201 on. I measured 5v and its pulsing.
I have a thermal camera but sadly there isn't any heat or even amp consumption to generate heat whatsoever.
Note: in the video I took it said somewhere like a 60 mAh was pulled apparently that was caused by the defective USB-C ammeter I took the video of. This does not harm the troubleshooting in any way or form because I used THIRD known-good ammeter.
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Re: Water damaged M1 MacBook Pro (820-02020)
Removed both fuses and tested connector's 5V side and they were very nice smooth 5.1V on each one.
I've returned one of the fuses FF200 and tested on AON side and cycling is back..
What does that mean? Guess it means that the cycling is caused by the other side? What ever is after PPDCIN_USBC_AON, no?Last edited by iMuhtaseb; 12-11-2022, 11:02 AM.
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Re: Water damaged M1 MacBook Pro (820-02020)
I've compared the diode readings of PPDCIN_USBC_AON with a known-good board I have here.
Bad board is [B]0.579[/B]
Known-good board is [B]0.577[/B]
Maybe the difference is there because of other types of multimeters were used?
Both fuses are working as they should with zero resistance in resistance mode reading.
I measured both CC1 and CC2 (CF413, CF414, CF513 and CF514) in diode mode.
I once again compared the numbers on the bad board with the known good board.. ...Last edited by iMuhtaseb; 12-11-2022, 10:42 AM.
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Re: Water damaged M1 MacBook Pro (820-02020)
The original 96W adapter is being used with Keweisi USB-C ammeter. They're working fine on other MacBooks.
And I've used another 96W and another USB-C ammeter (another brand) and it's doing the same thing.
I've taken a video of it:
[url]https://share.icloud.com/photos/07fsaT1x9T5nr9FAtqZTVeuGw[/url]Re: Water damaged M1 MacBook Pro (82...6W and another
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Re: Water damaged M1 MacBook Pro (820-02020)
Both both CD3217 have their LDOs showing proper voltages.
I have noticed a fluctuating on PPDCIN_USBC_AON going up to 5v then dropping 4.8-4.6v then going up 5v then down 4.8-4.6v
I have replaced both CD3217s just in case and it's same issue, now I have returned the originals.
What could be causing the fluctuating?
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Water damaged M1 MacBook Pro (820-02020)
USB-C ammeter takes 5V
PPBUS is 12.3V
3V8_AON is present
1V8_AON is present
PP3V3_S2 was not present but I found UC710 corroded so I replaced it and now I got 3V there but no 3.3V.. enable P3V3S2_EN is not present.. generated by U8100, master PMU.
I swapped the master PMU and slave PMU from a known-good donor board and my bad board still takes 5V..
I put the master and slave that I have removed from by bad board to the donor.. and it takes 20V. Meaning the chips are probably OK.
PP3V3_S2_UPC missing..
PP1V8 S2 missing
...
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Re: iMac 21.5 2017 4K no image on internal screen
I measured the MOSFET next the LED #4 and here are the measurements:
Q0304
1 = GND
2 = DP LINK OK = 0.0V
3 = GFX OK DRN = 0.0V
4 = GND
5 = GFX OK = 3.3 V
6 = GFX OK K = 1.2V
DP_LINK_OK being missing makes the LED #4 dims lightly as the schematics says (attachment below).. I traced back DP_LINK_OK source and it's U8800.. the AMD Radeon graphics card..
This is mind boggling, think it's something fixable? What should be my next step?...
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iMac 21.5 2017 4K no image on internal screen
820-00597
iMac 21.5" A1418 2017 4K is not showing an image properly.. It shows an image externally without issues but to the internal screen it's intermittent.
Another screen results the same thing, it's a main logic board issue.
I had doubts about the LVDS connector so I replaced it, still the same issue..
The main logic board diagnostics LEDs are 5.. #1, #2, #3 works OK but #4 is half on and #5 is off.. I don't know what #4 means while it's not completely off or completely on..
Anybody having an idea or seen this...
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Re: 820-00850 20V 0.0amps
Perhaps PP3V3_S5 is pulsing during power up ?
[B]Sadly, my multimeter is not advanced to good enough to detect quick pulses.[/B]
Also, review this thread:
[url]https://www.reddit.com/r/mobilerepair/comments/q9n9fa/a1989_82000850a_s5_rails_missing/[/url]
which notes that from Louis' youtube videos, corrupt T2 firmware could be the root cause.
[B]I've attempted DFU revive but haven't gone to restore, since it has important data on the logic board. [/B]
[B]This is the error I get...
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Re: 820-00850 20V 0.0amps
1) Do the posted voltage rails remain ON when you attach the adapter or do they power cycle ?
[B]• Yes, very nice and stable. [/B]
2) Are you using the suitable power adapter for this logic board ?
[B]• Yes, an Apple original 97W USB-C with an Apple original USB-C to USB-C cable. [/B]
3) Post the voltage readings for:
I2C_PWR_SCL is [B]1.79V[/B]
I2C_PWR_SDA is [B]1.79v[/B]
4) Remove all power. Meter in resistance mode. What is the resistance to ground for [B]PP3V3_S5...
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