Macbook Pro A1989 820-00850-a not powering on

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

The voltage of PPBUS_G3H should not be fluctuating.

Power down and desolder F7000 fuse. Then power up again and confirm if PPBUS_G3H is stable by measuring @ F7000, pad # 1 (fuse will not be in the circuit so there is no load from the consumer side of the circuit).

mon2 i think the combination of the ground point i was using and my probes was causing the fluctuations, i was wondering as to why it was happening randomly so i just tested again for good measure a couple of times at different ground points and its at a stable 12.29V now.

[mon2]

Re: Macbook Pro A1989 820-00850-a not powering on

reference:
https://www.logi.wiki/index.php?titl...a91ffa8e4775a9

Measure the voltage of:

I2C_PWR_SDA
I2C_PWR_SCL


* The I2C lines are used to configure the mode and voltage out of U7000. Confirming if the I2C lines are NOT stuck which will halt the communication with the U7000 buck/boost regulator.

and

TBT_T_SPI_CLK
TBT_T_SPI_CS_L
TBT_T_ROM_WP_L
TBT_T_SPI_MOSI
TBT_T_SPI_MISO
PP3V3_UPC_TA_LDO


Post the readings.

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

reference:
https://www.logi.wiki/index.php?titl...a91ffa8e4775a9

Measure the voltage of:

I2C_PWR_SDA
I2C_PWR_SCL


* The I2C lines are used to configure the mode and voltage out of U7000. Confirming if the I2C lines are NOT stuck which will halt the communication with the U7000 buck/boost regulator.

and

TBT_T_SPI_CLK
TBT_T_SPI_CS_L
TBT_T_ROM_WP_L
TBT_T_SPI_MOSI
TBT_T_SPI_MISO
PP3V3_UPC_TA_LDO


Post the readings.

I2C_PWR_SDA measured at Resistor R5280 PIN #1 - 1.79V (Also same voltage when measuring at PIN #2 but see the voltage oscillating here)
I2C_PWR_SCL measured at Resistor R5281 PIN #1 - 1.79V (Also same voltage when measuring at PIN #2 but see the voltage oscillating here)

TBT_T_SPI_CLK measured at UB090 PIN #6 - 0.63-0.63V fluctuating
TBT_T_SPI_CS_L measured at UB090 PIN #1 - 3.34V
TBT_T_ROM_WP_L measured at UB090 PIN #3 - 3.34V
TBT_T_SPI_MOSI measured at UB090 PIN #5 - 1.43-1.44V fluctuating
TBT_T_SPI_MISO measured at UB090 PIN #2 - 3.34V
PP3V3_UPC_TA_LDO measured at UB090 PIN #8 - 3.35V

[mon2]

Re: Macbook Pro A1989 820-00850-a not powering on

Do you see a steady voltage on TBT_T_SPI_MISO ?

MISO = Master in; Slave OUT. So this is the binary output from this flash IC to the host (Master controller) for the SPI bus.

That is, if indeed you see a static value then this flash rom is spitting out 'FF' = binary '1111 1111' = means the flash rom is blank / erased.

Suggestion at this point is to locate a donor board with the same flash rom and apply onto here or a clone of it.

One of the techs was supposed to post the dumps here ? Wonder if they have received it or forgot or filed under do not care. We can wait but if no one steps up on the flash rom dumps we will order the tool and post the contents.

See here - good video from REWA but believe there is a more current tool now that supercedes this one (Baiyi U301 tool):

https://www.ifixit.com/Guide/Repair+...c7239e9d95089c


https://www.aliexpress.com/item/1005...rch-mainSearch

[mon2]

Re: Macbook Pro A1989 820-00850-a not powering on

more...from Louis' website:

post the voltages for the following:

PP1V8_SLPS2R
PP1V8_AWAKE
PP1V1_SLPS2R
PP0V8_SLPS2R
PP0V82_SLPDDR
PP3V3_AWAKE
PPVDDCPUSRAM_AWAKE
PP0V9_SLPDDR
PP1V1_SLPDDR
PP1V2_AWAKE
PPVDDCPU_AWAKE

if the above are STABLE then you need to try a DFU restore. Personally have never done this but many articles & videos on the topic. Using a USB Type C cable and another working macbook, you should be able to restore this firmware. Really curious on the outcome of this one.

reference:
https://boards.rossmanngroup.com/thr...fc4f018ce70d5e

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

Do you see a steady voltage on TBT_T_SPI_MISO ?

MISO = Master in; Slave OUT. So this is the binary output from this flash IC to the host (Master controller) for the SPI bus.

That is, if indeed you see a static value then this flash rom is spitting out 'FF' = binary '1111 1111' = means the flash rom is blank / erased.

Suggestion at this point is to locate a donor board with the same flash rom and apply onto here or a clone of it.

One of the techs was supposed to post the dumps here ? Wonder if they have received it or forgot or filed under do not care. We can wait but if no one steps up on the flash rom dumps we will order the tool and post the contents.

See here - good video from REWA but believe there is a more current tool now that supercedes this one (Baiyi U301 tool):

https://www.ifixit.com/Guide/Repair+...c7239e9d95089c


https://www.aliexpress.com/item/1005...rch-mainSearch

I checked again on my multi meter and TBT_T_SPI_MISO is staying at 3.34V. So am i right in thinking that this would be something measurable on the multimeter? I do not have a oscilloscope.

Ok so would you say that this is a safe bet, just considering the few anomalies we experienced, with the strange behavior previously where when i had removed the Diode off the board i had the power delivery negotiation taking place and had the machine on at 20V. In that case how does the flash rom get blank / erased?

Also another anomaly for me was one when the USB port associated with CD3215 - U3200 refusing to switch on when I had soldered on the new diode onto the logic board.

I wanted to check this, another maybe, also anomaly so when taking a diode mode reading on the capacitor C3201 at PIN #1 for voltage line PP20V_USBC_XB_VBUS for CD3215 - U3200 i get a reading of .584 however the other 3 lines (PP20V_USBC_XA_VBUS, PP20V_USBC_TA_VBUS, PP20V_USBC_TB_VBUS) connected to the other three CD3215's at their respective capacitors show a .193 diode reading instead?

That is, if indeed you see a static value then this flash rom is spitting out 'FF' = binary '1111 1111' = means the flash rom is blank / erased.

I love this kind of information! Ha. Thanks.

I feel like after taking all these diode readings today i have been initiated in to the diode club. Haha.

UPDATED:

I just seen your other post to check those other voltages, i will report on that one once i am again back at logic board.

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

mon2 here are the additional voltages/readings you requested:

PP1V8_SLPS2R measured at UB090 PIN #1 - 1.7V
PP1V8_AWAKE measured at R6803 PIN #1 - 1.7V
PP1V1_SLPS2R measured at L7814 PIN #2 - 1.09V
PP0V8_SLPS2R measured at C4423 PIN #1 - 0.79V
PP0V82_SLPDDR measured at L7811 PIN #2 - 0.82V
PP3V3_AWAKE measured at C4595 PIN #1 - 3.33V
PPVDDCPUSRAM_AWAKE measured at L7810 PIN #2 - 0.80V
PP0V9_SLPDDR measured at C7819 PIN #1 - 0.89V
PP1V1_SLPDDR measured at U7901 PIN #5 - 1.09V
PP1V2_AWAKE measured at C4550 PIN #1 - 1.20V
PPVDDCPU_AWAKE measured at C7825 PIN #1 - 0.75V

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

I2C_PWR_SDA measured at Resistor R5280 PIN #1 - 1.79V (Also same voltage when measuring at PIN #2 but see the voltage oscillating here)
I2C_PWR_SCL measured at Resistor R5281 PIN #1 - 1.79V (Also same voltage when measuring at PIN #2 but see the voltage oscillating here)

TBT_T_SPI_CLK measured at UB090 PIN #6 - 0.63-0.63V fluctuating
TBT_T_SPI_CS_L measured at UB090 PIN #1 - 3.34V
TBT_T_ROM_WP_L measured at UB090 PIN #3 - 3.34V
TBT_T_SPI_MOSI measured at UB090 PIN #5 - 1.43-1.44V fluctuating
TBT_T_SPI_MISO measured at UB090 PIN #2 - 3.34V
PP3V3_UPC_TA_LDO measured at UB090 PIN #8 - 3.35V

Just to add to my previous post #23 of this thread the voltage readings i had posted TBT_T_SPI_CLK etc were for the ROM chip - UB090. I forgot to post the readings for the other ROM chip - U2890. I have posted these below in case anyone is following the thread so far.

TBT_X_SPI_CLK measured at U2890 PIN #6 - 0.66 - 0.67V
TBT_X_SPI_CS_L measured at U2890 PIN #1 - 3.34V
TBT_X_ROM_WP_L measured at U2890 PIN #3 - 3.34V
TBT_X_SPI_MOSI measured at U2890 PIN #5 - 1.36-1.37V
TBT_X_SPI_MISO measured at U2890 PIN #2 - 3.34V
PP3V3_UPC_XB_LDO measured at U2890 PIN #8 - 3.34V

UB300
PP3V3_UPC_TA_LDO measured at C3208 PIN #1 - .522
........

Also in my previous post 13 the PP3V3_UPC_TA_LDO diode reading was measured at CB308 not C3208.

[mon2]

Re: Macbook Pro A1989 820-00850-a not powering on

TBT_X_SPI_CS_L measured at U2890 PIN #1 - 3.34V

Just realized that you posted this voltage but the CS# (chipselect) is ACTIVE LOW. So this line needs to be a logic low (~0v) to ENABLE this flash device.

Can you also measure & post the voltage of UPC_TA_SPI_CS_L ?

If this CS# is ~3v3, then the flash rom is not being selected. It is possible that your meter is not fast enough to capture this event (ie. could be LOW briefly and then goes HIGH after the host determines there is nothing of value inside this memory device). Sometimes, firmware will contain special header details inside the memory device that must match the expected value else it is considered to be corrupt firmware.

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

Just realized that you posted this voltage but the CS# (chipselect) is ACTIVE LOW. So this line needs to be a logic low (~0v) to ENABLE this flash device.

Can you also measure & post the voltage of UPC_TA_SPI_CS_L ?

If this CS# is ~3v3, then the flash rom is not being selected. It is possible that your meter is not fast enough to capture this event (ie. could be LOW briefly and then goes HIGH after the host determines there is nothing of value inside this memory device). Sometimes, firmware will contain special header details inside the memory device that must match the expected value else it is considered to be corrupt firmware.

mon2 here are the measurements i took, see below and thanks for the attachment Chip Select (/CS) description.

UB090
UPC_TA_SPI_CS_L measured at Resistor RB281 PIN #2 - 3.34V

U2890
UPC_XB_SPI_CS_L measured at Resistor R3096 PIN #2 - 3.34V

You are right this was a tricky one to capture, but i managed it, on the multimeter so i had to have my probes ready on the logic board/flicked on my plug socket power switch and for a brief moment you can see it gets to 3.34V and then the voltage goes down to 0.00V then back to 3.34V.

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

mon2 here are the measurements i took, see below and thanks for the attachment Chip Select (/CS) description.

UB090
UPC_TA_SPI_CS_L measured at Resistor RB281 PIN #2 - 3.34V

U2890
UPC_XB_SPI_CS_L measured at Resistor R3096 PIN #2 - 3.34V

You are right this was a tricky one to capture, but i managed it, on the multimeter so i had to have my probes ready on the logic board/flicked on my plug socket power switch and for a brief moment you can see it gets to 3.34V and then the voltage goes down to 0.00V then back to 3.34V.

UPDATE: So i soldered back on the Diode D3370 and decided to reflow U3100 as there was corrosion around that area when i first received the board. Now I plugged in the USB charge cable but this time two things are different, the USB port that was not turning on previously when i had put on the new diode is turning on again but still showing 5.1V but now it is at 0.00 amps. When i plug into the other USB port it is again 5.1V but on that one its drawing 0.89amps and U3100 is burning up! Hot to the touch.

An observation: also when i plug the USB charger cable into one of the other 2 USB ports on the other side of the board where UB300 and UB400 is situated, U3100 still gets hot and you still see the 0.89amps draw.

I think it seems now the CD3215 - U3100 is the culprit. I am going to reattempt to replace. Where would i be able to order one of these and which one do i need? On the chip it says 'CD3215C00'.

[mon2]

Re: Macbook Pro A1989 820-00850-a not powering on

Be sure to share the full details of your markings and logic board with the vendor but here is a store we trust and use often:

US $13.79 11%OFF | 2-10pcs UB300,UB400, U3100, U3200

https://a.aliexpress.com/_mtX0PcE

Also ask about a direct heat stencil for this part and a stone fixture, metal spatula to reball and solder paste the parts, if needed.

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

Be sure to share the full details of your markings and logic board with the vendor but here is a store we trust and use often:

US $13.79 11%OFF | 2-10pcs UB300,UB400, U3100, U3200

https://a.aliexpress.com/_mtX0PcE

Also ask about a direct heat stencil for this part and a stone fixture, metal spatula to reball and solder paste the parts, if needed.

Thanks mon2 which stone fixture which would you recommend? Also i found this stencil https://www.ebay.co.uk/itm/203492914...AAAOSw35BgxpsZ

Just wanted to correct my most recent post #31 above, when i mentioned i had reflowed U3100 what i’d meant to say was I had reflowed the components surrounding U3100. But because I love under I will get my chance with the U3100 when i go ahead and replace.

[mon2]

Re: Macbook Pro A1989 820-00850-a not powering on

The shop that sells the cd3215 can probably source the reballing tools.

There are 2 stencil types. The thin and direct heat type. The direct heat type does not warp during heating. Maybe consider both styles.

Here is a video of the thin stencil type in use:

https://youtu.be/JJKxYCBjBEI

Here are the tools:

MasterXu Amaoe CD3215 CD3215C00 CD3217 CD3217B12 TPS65982 BGA Reball Kit 4in1 for Mac Pro Repair Mainboard A2159 A1989 A1990 A17
https://a.aliexpress.com/_mKra7YS

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

The shop that sells the cd3215 can probably source the reballing tools.

There are 2 stencil types. The thin and direct heat type. The direct heat type does not warp during heating. Maybe consider both styles.

Here is a video of the thin stencil type in use:

https://youtu.be/JJKxYCBjBEI

Here are the tools:

MasterXu Amaoe CD3215 CD3215C00 CD3217 CD3217B12 TPS65982 BGA Reball Kit 4in1 for Mac Pro Repair Mainboard A2159 A1989 A1990 A17
https://a.aliexpress.com/_mKra7YS

Thanks mon2, I appreciate all your help on this, I have just ordered the parts and I will report back in on this one once they have arrived and have them all back, soldered on.

I ordered the BGA Reball kit you sent the link to, I understand AliExpress lead times vary and can take a while so in the meantime i also ordered that stencil from ebay as well and a CD3215 chip from ebay, that way, in principle I can try and get this one done quicker.

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

Hi mon2, just a update on this, so i received the replacement CD3215 and had it back soldered on to the board and i was still getting the same results.

So i decided to investigate some more throughout the immediate area and noticed something was different here, i have drawn 2 arrows from Resistor R3430 and R3440 (see image below) each at PIN #2 going to each of the respective capacitors C3113 & C3114 carrying signals USBC_XA_CC1/USBC_XA_CC2.



I measured using diode mode for continuity between the two points, one probe at PIN #2 of one of the resistors and one to its respective capacitor at PIN #1. I was getting the reading of 0L. So I decided to measure the other three working CD3215 at these same points for continuity and for the other 3, I am getting beeps here, showing continuity. First I thought that the replacement CD3215 was bad, so i removed it and measured again and it still measures at 0L. Do you think a bad CD3215 could cause this or if not any ideas what could be causing this to happen? Has something happened to the board internally because of the liquid damage that the board had experienced before?

P.S I know there is three pads missing under the CD3215, they came off when i desoldered the replacement CD3215 off the logic board again. I am waiting for some circler soldering lugs to arrive so i can reconstruct the area.

[Simplebeans]

Re: Macbook Pro A1989 820-00850-a not powering on

Hey guys just thought I’d provide an update on this in case anyone was following. A continuation from my last post above, when I was getting the 0L continuity reading in diode mode when measuring at Resistor R3430 and R3440 at PIN #2 going to each of the respective capacitors C3113 & C3114 carrying signals USBC_XA_CC1/USBC_XA_CC2, I decided to check the diode mode readings at the FPC connector J3300 at PIN #52 (USBC_XA_CC1_CONN) and PIN #53 (USBC_XA_CC2_CONN) and was also getting a reading of 0L so i concluded that maybe the FPC J3300 connector needed replacing due to a internal short within the connector having checked everything else on the immediate U3100 circuit.

I was contemplating still at replacing the FPC connector. I decided i would heat the board up one more time around the previous area of corrosion that the logic board had arrived with, and whey and behold something different again. Now when i plug the USB charger in to the USB port connected to the U3100 i still get the same result my USB tester does not switch on. However now on the other three USB ports i am getting 5V negotiated to 20V and the machine is now powering on!

Ok so it’s not exactly the desired result however it seems to be against the standard curve explanation of requiring all 4 CD3215's to work before 20V power delivery can be negotiated. I have decided then now because i was undecided on replacing the FPC connector anyway as i know how these things can be to keep the machine for my work space so i can use it for testing. DFU revivals and restores if required etc as it is.