L9780 has no voltage, and is not shorted. 14kohms all over it. High res.
Same with PP1v8_S2 measuring right next to it at L7830 & other capacitors next to it.. No Voltage and also high resistance....
applejuice95
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Last Activity: Today, 12:35 PM
Joined: 05-02-2023
Location: Mooresville NC
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Looking around the speaker IC where there was corrosion. I went ahead and replaced the Capacitor and UR730 just for peace of mind.. I noticed in the schematics that 1.8 AWAKE runs this rail. Curious where 1.8 Awake comes from I found this page, showing UR500.. Where PP1v2 goes in, and PP1V8 AWAKE comes out.. So I checked for PP1V2 Awake at LR500, and it is indeed NOT present. 0 Volts...
So I went back to PP1V2 AON.. Checked for it on C7772, and there IS 1.2V there.
So I'm thinking, Get 1.2V back to L500, which should get 1.2V to UR500 to create the 1.8V AWAKE rail....Leave a comment:
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3 USB-C 14", plus the MagSafe 3
All 3 ports are 999.ohms 5.23V and 0.00A...Leave a comment:
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No Response with Configurator....Leave a comment:
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What if, we set up the unit for a DFU revive and while running through the process -- we inject 1.8V into the 1.8 rail.. Just give her what shes missing.
If its incapable of sending 1.8V through the rail potentially due to a firmware corruption, but the only way to fix the corruption is a DFU. Supplement the voltage with an artificial V-IN? Anyone ever done this?
This is one of those, "sounds good on paper" ideas but, hey who knows.Leave a comment:
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Waiting for one coming off of eBay then going to re-run it.
You think its possible with that rail being absent that DFU revive can still be a possibility?...Leave a comment:
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Heres the item: https://www.mobilesentrix.com/usb-c-...2485-late-2021
Says compatible with M3 14" & 16"
I do not believe this to be true. The part number for the M1 Pros is indeed 820-03084-02/ 923-10062 and this is indeed what they're selling.
For A2991/A2992 M3 models. the part number is 821-04548-A (or 821-04548-01)
Similar to how the A1707 ports were different from A1990 even thought the connector was the same.
I believe installing this part, and plugging up power may have...Leave a comment:
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Have any more ideas?
I can't help but feel like this was caused by installing the wrong USB-C i/o board.
Mobile Sentrix sells them, but they're selling A2442/A2485 i/o boards as being compatible with A2992/A2991 M3 models which it is not.. Different part number entirely.
Originally client had a no response machine. We inspected the usb-c port that works with PP1V5_UPC2_LDO_CORE .. It was all burned up. Removed it, and reinstalled board with this one i/o board removed from the equation. There was a tiny amount of corrosion near U730 we cleaned, but the machine...Leave a comment:
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- The 3 USB-C PDs
PP1V5_UPC0_LDO_CORE - 1.5V
PP1V5_UPC1_LDO_CORE - 1.5V
PP1V5_UPC2_LDO_CORE - 1.5V
- The MagSafe
PP1V5_UPC5_LDO_CORE - 1.5VLeave a comment:
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PP3V8_AON - Resistance to Ground = 400ohms (starts around 100, builds up, stabilizes at 400).
(With Power cable in USB-C port #2) These are the voltages for UF500
PP3V3_UPC1_LDO (UF500) - 3.23V
PP1V8_UPC1_LDO (UF500) - 0.00V
PP1V5_UPC1_LDO_CORE (UF500) - 1.5V
Yes it would seem 1.8V rail is absent. 1.8V rail is also absent when power is moved to USB-C port #1 (just right of the MagSafe) - 3.3V is present on UF400, but 1.8V is not.
Checking for resistance to ground with power removed,
PP1v8_AON on C2221 - 23kOhms
PP1V8_S2...Leave a comment:
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Thanks Mon, checking on Monday. we are closing out for the weekend. Thank you for all of your help, talk later....Leave a comment:
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PPCHGR_VDDA - 4.46 V
PPCHGR_VDDP - 4.416 V
SMBUS_BATT_SCL - 0.0V
SMBUS_BATT_SDA - 0.0V
(board is out of machine, on bench)Leave a comment:
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Measuring at C5253 & C5254 - 135ohms same thing near C9803Leave a comment:
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A2992 - 5V - 0.00A - No Power
820-02918 - 2023 M3 A2992
- 5V 0.00A on Meter - USB-C
- No light on MagSafe
Small corrosion on UR730, and CR765 - Cleaned and scrubbed with ISP
Re-assembled. Tested, and computer worked, battery charged. Today after replacing a new USB-C I/o board, the machine no longer works.. We realized this was the wrong part, it was a port for A2442/A2485. The M3 uses a new part 821-04548-A.
After this, now computer has no power.
-PPBUs_AON = 0.00V
-PP3v8 = 0.00V
- PPDCIN_AON (F5600) - 5V
No DFU mode. -
Replaced from donor board, still the only thing glowing. Its only at 27c though. Nothing crazy.
Thank you for the power sequence chart. Thats actually really nicely broken down....Leave a comment:
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A1466 - 820-00165-A No Boot No Fan Spin
Hello, we have an 820-00165-A Board.. Does not power ON, Fan does not spin. Charger light is ON
Charger light is green or amber, functioning based on battery charge. (Charging - Amber) (Fully Charged-Green)
The light does not change from amber to green, when resetting the SMC.
With board on bench removed from mac, new I/O board and cable hooked up. When plugged in, amber light, no power. Confirmed with tester pads as well for the power button.
PPBUS_G3H = 8.6V
SMC_PM_G2_EN = 3.4V
U7100 under thermal is glowing...
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