820-00163-A Thunderbolt Detection Issue

[ideachief]

I have an 820-00163-A logic board that does not detect Thunderbolt devices or output video via DisplayPort on either port A or B, HDMI output works. ThunderBolt shows in System Profiler, no devices connected. Checked HPD voltage goes to ~3.2V when DisplayPort is connected but stays 0.0V when Thunderbolt Device (TB Ethernet Adapter) is connected. 15V TB Boost voltage (measured at U3090) was present. Both TB Ethernet Adapter and DisplayPort monitor work fine on other Macbook Pro. Any assistance is greatly appreciated

 

[2informaticos]

First of all, welcome to the forum!

Any history fault available?

Both DP_TBTPA/PB_HPD go high when connect external monitor to corresponding port?
Be sure to get all output voltages from U3210/310.
Also check U2800 voltages, at page 29.

You can try changing TBT ROM (U2890).
Let U2800 as last option...

 

[ideachief]

Thanks for the reply. I'll have to take those measurements this evening after work.

 

[ideachief]

Ok, so first, I must have been measuring the HPD on the wrong pin.

From the Test Points, DP_TBTPA_HPD or DP_TBTB_HPD does NOT go high when monitor (mini-DP) is connected (max 0.1V) to either port.

Here are the measured voltages on the corresponding IC:

U3210
V3P3OUT (pin 18) = 3.287
OUT (pins 12 & 14) = 3.328

U3310
V3P3OUT (pin 18) = 3.310
OUT (pins 12 & 14) = 3.318

U2800
P1V05TBT_SW = 1.042
PP1V05_TBT = 1.004
PP1V05_TBTCIO = 0.999
PP1V05_TBTRDV = 0.998
PP3V3_S4_TBT = 3.305
PP3V3_S4_TBT_F = 3.304
PP3V3_TBTRDV = 3.304
PP3V3_TBTLC = 3.303

If I am missing voltages, please let me know. Everything seems nominal, with the obvious exception of the HPD not going high. And thank you for your help.

 

[ideachief]

Another thing, I was checking Q8000 (per https://repair.wiki/w/A1398_2015-2016_15”_MacBook_Pro_Retina) and noticed that P3V3S3_S4 is 0V. PP3V3_S4 and PP3V3_S5 are both ~ 3.3V.

 

[2informaticos]

Considering port A, TBT_A_HPD must go high when connect external monitor there.
At same time, U3220 should send out high level at DP_TBTPA_HPD.
Of course, 3V3 is required at DP_PWR pin of J3200.

Which is your actual case?
You may need to change U3220/320.

 

[ideachief]

So, measuring TBT_A_HPD at J3200 (pin 22) I get ~3.3V. Measuring DP_TBTPA_HPD at U3220 pin 12 (TP[1]DP_TBTPA_HPD), I only get 0.098V. Does that indicate that most likely U3220 (and U3320) are bad?

 

[ideachief]

Just FYI, Tried swapping U3220 from donor board and no change.

 

[ideachief]

Don't know if it is helpful, but here are all the voltages from U3220 measured at the IC:

U3220
DP_TBTPA_AUXCH_N Pin 1 = 0.986
DP_TBTPA_AUXCH_P Pin 2 = 0.583
PP3V3_S4_TBTAPWR Pin 3 = 3.236
DP_TBTPA_DDC_DATA Pin 4 = 0.029
DP_TBTPA_DDC_CLK Pin 5 = 0.788
TBT_A_DP_PWRDN Pin 6 = 0.956
TBT_A_D2R_C_N<1> Pin 7 = 0.487
TBT_A_D2R_C_P<1> Pin 8 = 0.481
Pin 9 = GND
DP_TBTPA_ML_N<1> Pin 10 = 0.004
DP_TBTPA_ML_P<1> Pin 11 = 0.008
DP_TBTPA_HPD Pin 12 = 0.114
TBT_A_LSRX Pin 13 = 0.082
TBT_A_LSTX Pin 14 = 0.095
TBT_A_CIO_SEL Pin 15 = 0.00
TBT_A_CONFIG1_BUF Pin 16 = 0.114
TBT_A_HPD Pin 17 = 3.254
TBT_A_CONFIG1_RC Pin 18 = 3.131
DP_A_LSX_ML_P<1> Pin 19 = 0.010
DP_A_LSX_ML_N<1> Pin 20 = 0.009
Pin 21 = GND
TBT_A_D2R1_AUXDDC_P Pin 22 = 2.65
TBT_A_D2R1_AUXDDC_N Pin 23 = 2.758
TBTDP_AUXIO_EN Pin 24 = 0.999

 

[2informaticos]

"You can try changing TBT ROM (U2890).
Let U2800 as last option..."

 

[ideachief]

Well, I replaced U2890 and still nothing. The MacBook still shows the Thunderbolt controller, but doesn't detect anything plugged into it. I suppose I could replace U2800, but I don't think it's worth it at this point, not to mention if I did and it didn't work...

 

[2informaticos]

Did you pick the TBT ROM from donor board, same model?

Once HDMI output is good, I don't see a real reason to use thunderbolt connectors.
Nobody really needs LAN connection with a laptop.

 

[ideachief]

I wanted to thank you for your assistance, but I just ended up buying a replacement board where everything worked, for a very decent price.