MacBook Air A2337 820-02016 no power 5v

[federicoc]

Hello everyone,
macbook air a2337 was brought to me dead, no power
The type c meter is stuck on 5v with low absorption and after a while it restarts.
I changed the two cd3217 because there was a low resistance to ground, the resistance is now ok but the problem persists.
These are the lines I measured
PPBUS AON: 11.98-12.25V
PPDCIN_AON_CHGR_R: 5.12V
PP1V5_UPC0_LDO_CORE: 1.58V
PP3V3_UPC0_LDO: 3.3V
PP3V3_S2_UPC: 3.3V
PP1V5_UPC1_LDO_CORE: 1.58V
PP3V3_UPC1_LDO: 3.3V
PP1V8_AON: 1.8V
PP3V8_AON_VDDMAIN: 3.8V
PP3V3_S2: 3.3V
PP2V5_AWAKE_NAND: 2.5V
PP1V25_S2: 1.22V (resistance to ground 0.252, is it low?)

Thanks for your help and interest

[mon2]

From where did you source the pd controllers? That may be the fault.

[federicoc]

From a macbook pro a2141 motherboard
They have the big dot, while the original ones had the small dot.
Are they not compatible?

[hopkok]

Hi, I have same problem, customer said, forgot MAC on direct sun, when he came back, was off. Put on charger, charging icon came on, but from this time was not able to turn it on anymore. I checked board and found faulty UF400, low resistand and under thermal camere there was heating spot. I took UF400 from exatly same board and now have same issu like you.

Found this informations: " Check voltage on PPBUS_AON

• Measure voltage on PPBUS_AON by placing your multimeter in DC mode, black probe on ground, and red probe on PPBUS_AON. A suitable measuring point on the 820-02016 logic board is C5960 (Figure 1). Normal voltage should be around 12.60-13.1V.
• If the voltage is approximately 12.28-12.35V, it may indicate a communication issue between the SOC and PMICs, or corrupt firmware.
• If the voltage is 0V, proceed to the repair steps for shorted or absent PPBUS_AON voltage.

So there should be "communication issue between the SOC and PMICs, or corrupt firmware."

Did you solve your issue?
"

[hopkok]

From where did you source the pd controllers? That may be the fault.

Hi Mon2, if I take PD controller from exactly same board that should be working, right?
Thanks

[mon2]

Review this:

https://logi.wiki/index.php/M1_MacBooks#CD3217_Repair

Also suggest to use a part from the same physical location on the donor board as the internal SMBUS address for the controller may be different.

[hopkok]

I used exactly the same PD controler, UF400 replaced with UF400...
I need to dig out customer data from this board, is any way to start it from charged battery?

[mon2]

What does the USB-C meter report for voltage and current draw?

[hopkok]

5V, 0,44Amps, restart every 5-6 seconds...

[mon2]

If you have a restart, the board is power cycling. Would you have a USB-C port tester? Like Qianli tail bridge? Very handy tool to quickly gauge if the USB-C port pins are mating properly to the PD controllers. Also is able to test the Lightning port. We paid ~20$ (Canadian).

Would you have a thermal camera? Check the SPI flash for voltages.

[hopkok]

Unfortunately, I do not have USB-C tester. I have thermal camera. SPI mean U1970 or UF260?

[mon2]

Check both.

UF260 = TBT / PD controller ROM.
U1970 = SOC ROM.

Both should show activity. In the event that there is ROM corruption, the dumps of each should be available. Have you attempted a DFU to see if the unit is able to connect?