820-01814 strange USB activity

[samolo75]

Thanks in advance for the help,
I got this mother board with a problem I am not able to find.
- All four USB C ports are ok for charging.
- The two USB ports on the left do not recognize any USB device (only the charger)
- The two USB ports on the right will make a USB Hub work to connect a external monitor but will not recognize any USB 2 device connected to it.

I reflow all CD3215C00Z and no changes

I went through this post (https://www.badcaps.net/forum/showth...ighlight=UB000) and did all the checks and all looks good, including UPC_T_5V_EN (3.3V), it shows 0V if only the charger is connected to that side.

Can it be a problem of the CD3215?

Appreciated any ideas, Thanks!!

[samolo75]

Re: 820-01814 strange USB activity

I did some test. I connected a USB amp meter with a mouse dongle. In a working computer it gets 24mA in working condition. Interestingly, when connected to the faulty board, at the beginning of the booting also gets 24mA, but after a minute or two, the apple logo still on the screen (no progress bar yet but about to show up) the current drops to 6mA.
UPC_T_5V_EN and UPC_T_5V_R stay 3.3V all the time

USB_UPC_TA_F_P looks fix to 3.0V
USB_UPC_TA_F_N 3mV

I am not sure if that means anything. This coming from the CD3215 where the USB is connected.

I reballed both CD3215 and same issue, nothing changed.

[samolo75]

Re: 820-01814 strange USB activity

PP0V9_TBT_T_LC = 0.87v
PP0V9_TBT_T_PCIE = 0.87
PP0V9_TBT_T_LVR =0.87v
PP0V9_TBT_T_SVR = 0.88v
PP3V3_TBT_T_ANA_PCIE = 3.3v
PP3V3_TBT_T_ANA_USB2 = 0v <==== No shortcut R=2MOhms Diode mode = 0.48
PP3V3_TBT_T_LC = 3.3V
PP3V3_TBT_T_F = 3.3V
PP3V3_TBT_T_SX = 3.3V
PP0V9_TBT_T_SVR = 0.88V
VR0V9_IND_TBT_T = 0.88V
TBT_T_USB_PWR_EN = 3.3V
TBT_T_PCI_RESET_L = 3.3V
USBC_T_RESET_L = 3.3V

[mon2]

Re: 820-01814 strange USB activity

See if this helps:

https://boards.rossmanngroup.com/thr...5v-225a.60021/

[samolo75]

Re: 820-01814 strange USB activity

Thanks for the reply! Which part do you think it is the most interesting. I already went through the DFU and nothing changed. In my case the 20V gets negotiated correctly on all 4 USB C ports (with or without battery connected), and connecting the external monitor the systems boots "correctly".

[mon2]

Re: 820-01814 strange USB activity

The power delivery contract negotiations occur using the CCx lines on each type c connector, not the D+/D- pins which are used by your USB 1.1/2.0/3.x widgets for data transfers. USB 3.x widgets use additional interface pins which are likely relevant to your USB hub device being tested.

Test a strict USB 1.1 or 2.0 device like a USB mouse. Does that work on each and every port? There are type C to type A dongles to allow for the USB mouse to be tested.

Remove all power. Meter in diode mode.

Red meter probe, yes red to ground.
Black meter probe to point to test.

Start with a known good port and measure each USB connector pin to validate a good diode reading of D+/D-, etc.

Then compare the same against the non-working port.

Post your measurements. My suspicion is that a transient event has killed some tvs diode(s) on the respective port.

[samolo75]

Re: 820-01814 strange USB activity

These are the measurements in diode mode:
TB USB BOT N = OL
TB USB BOT P = OL
TB USB TOP N = OL
TB USB TOP P = OL
TB CC1 = 0.9
TB CC2 = 0.9

TA CC1 = 0.99
TA CC2 = 0.99
TA USB BOT N = OL
TA USB BOT P = OL
TA USB TOP N = OL
TA USB TOP P = OL

The difference with the other side is that XA_USB_DBG_XXX_N and P are 0.3 which I think it is normal. I think this is the port for DFU, and DFU works.

But to make it clear. USB2 devices do not work on any of the USB C sides. Left or right. What it works on the left side is, apparently, everything else but USB2 devices.

Doing more tests I found that waiting for around 20 min after the computer is on, USB 2 devices (a mouse) will start working on all 4 USB C ports but if I move the USB hub with the display connected from the left side (the working one for external display) to the right side it does not work, and it will make the right side not to work again for USB 2.

I am a bit lost

Thanks for your help

[samolo75]

Re: 820-01814 strange USB activity

I measured TBT_WAKE_3V3_L and it is 3.3V, is that the correct value?
PP1V8_SLPS2R is 1.8V
I was expecting that Wake_3V3_L would mean that 0V is for wake up and 3.3 is not.
Same with PP1.8V8_SLPS2R being present, 1.8V, it would mean go to sleep? But also I found that voltage is used for many other stuff and all seems ok with the rest of the functionality.


I compared when the computer just booted and USB mouse not working and after the around 20min when USB mouse works and the values are the same. I could not measure TBT_WAKE_L as I have the board mounted at the moment and those points are on the side facing down.

I think I already mentioned, all four USB ports charge the battery without issue, the negotiate the 20V and the computer boots.

One more observation UPC_XB_FAULT_L is 3.3V, also not changing if the USB mouse works or not. When I touch the resistor to measure the voltage the USB mouse goes off and on again, but that might be normal if the impedance is high, I guess.

[mon2]

Re: 820-01814 strange USB activity

Review this thread - perhaps the same case as yours?

https://forums.macrumors.com/threads...#post-32194827

[samolo75]

Re: 820-01814 strange USB activity

Thanks for taking the time to help me. I will mount the MB back and look for updates, but this Macbook is an intel one, worth trying.
I realized the WAKE lines are unrelated as they are to wake up from sleep and not the state of the system
I measure P5VUSBC_X_PGOOD on U3500 and it is 0.05V (USB nor working). I did not manage to make it work and check again. One of the times I checked it was 0.2V.
P5VUSBC_X_RTN_DIV is 0V
P5VUSBC_X_VBST is 9V
I am not sure what the values are supposed to be. In diode mode non of them show shortcuts and measure around 0.5 which looks ok
Thanks again. I will report back after trying to see if there is any updates.

[mon2]

Re: 820-01814 strange USB activity

What is the voltage to ground of L3500, pin # 2 ?

[samolo75]

Re: 820-01814 strange USB activity

L3500 pin 2 is 5.22V
Are any of the voltages I wrote before wrong?

[mon2]

Re: 820-01814 strange USB activity

Need to review the list again with a focus but the following sticks out:

P5VUSBC_X_PGOOD

According to the datasheet and most similar power good signals, the pin is an open-drain output. That is, the pin is able to pull this pin LOW (~0 volts) and once the power rail that is linked to this signal is considered to be within proper range, this IC will release this signal pin to allow it to float. In the opposite state, this released state = high-Z = high impedance and respectively, requires an external pull-up resistor to define the 'soft high' logic level.

In reviewing the schematic, there is no pull-up resistor on this signal line and also this pin is not used by other logic. This pin is literally a no care signal.

For this reason, this signal pin is ok at the measured voltages due to the missing pull-up resistor. So even though the regulator is able to provide a valid output voltage rail, this signal is not a logic high.

regulator datasheet:
https://www.renesas.com/us/en/docume...870b-datasheet

[samolo75]

Re: 820-01814 strange USB activity

Thank you for looking into it. Makes sense. I think it must be something common to both sides (x4 USBC ports). Or one side affects the other. Could the CD3215 induce such a failure without any outside signs?
When I connect the mouse from the beginning and I boot, the bottom light of the mouse lits for around 30 sec or 1 min (while the apple logo is on) and just before the progress bar shows up the mouse light goes off. One in the OSX and after around 20min the mouse light goes on and it works.

[mon2]

Re: 820-01814 strange USB activity

Do you see the external power adapter negotiate 20V on each and every USB Type C port on this laptop?

Try to boot with a SMC bypass and note if the results are different.

[samolo75]

Re: 820-01814 strange USB activity

Yes, it negotiates 20V and boots from all 4 USB ports. But the USB hub with the external monitor only works on the two ports on the left side. I will try the SMC bypass. Thanks

[samolo75]

Re: 820-01814 strange USB activity

I am not sure I am doing it right to boot with SMC bypass. I try by turning of the computer, press and hold the power button, then I connect the USBC charger and keep holding the power button for 10sec. It just looks like it boot in normal mode. I do not see any difference at least. I tried with and without the battery connected. Without the battery, if I hold the button pressed for too long it negotiates the 20V but stays at 0.06A and does not boot. The mouse light goes on at the beginning as before. I also tried reseting the SMC, as I already did, and safe mode. No changes

[samolo75]

Re: 820-01814 strange USB activity

I updated to Ventura 13.4 and no changes.
What I did and things changed a bit is. I booted up holding the Option key to go to the boot up menu and there the mouse was working on all 4 ports with no issues. The external display would still only work on the left ports and not on the right.

[mon2]

Re: 820-01814 strange USB activity

Given that the USB mouse functions with the option key during boot, the hardware is not the fault.

[samolo75]

Re: 820-01814 strange USB activity

Do you think that maybe the rom UB090 could produce this failure and needs reprograming?
I tried DFU revive like 5 more times and no changes. The progress bar gets a bit less than 50% and then the target macbook boots to the login screen, and no error shows in the host computer, so I understand it all went fine.