820-02100/02098 LCD Backlight Controller IC UP800..

[Timp74]

To answer my own questions... I finally had the time to look at this machine again now that the boardview is availble. Turns out the machine wasn't powering on because there was crap under the slave PMIC. Took me a while to work out. I noticed that the 1v8_s2 rail was beening pulled up to 2.1v by 3v8_aon, there was 300 ohms between the rails, it should be Kohms. I guess other rails were off too. Anyway I soaked the board in isoproponol for a few hours and ran a flux cleaner under the slave PMIC. The machine now boots and works fine. I don't see any reason the a missing backlight bucks/boost controller IC should stop the boot process. There doesn't seem to much activity on it's I2C bus before AWAKE. The leason learnt is that this macbook won't assert the AWAKE signals unless all the preceding rails are at the correct voltages and drawing the expected current. It seems quite a common place for liquid damaged macbooks to get stuck at once all the obvious things have been fixed.

[NAZAREPAIR]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

Hello people. I have a question maybe some of you knows the answer, i have this macbook on my hands this time without backlight, i took a lot of messurments around the screen conector and backlight ic, and it looks to me that this is a ic problem. My question is i saw some guy talking that this chip is married to the cpu or something like that, and that can not be replaced. Is this true? I was thinking about order one of this (RENESAS 209100B1), but now i am worried that it wont work, does anybody here can confirm this? Or anybody here replace already this ic succesfully? Thank you so much!

[PickledOnion]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

Here is some readings from my non working board.

L8280 pp1v2_s2 0.2130 cycling 0 - 0.5v
l8230 pp1v8_s2sw 0.2860 cycling 0 - 0.7v
l8220 ppvdd_ecpu_sram_awake 0.3666
l8290 pvdd_fixed_s1 0.1698 0v no short
l8200 pvdd_ecpu_awake 0.0795 or 217 ohms tg
l8272 pp0v81_s1_sram 0.1745
l8210 ppvdd_gpu_bmpr_s1 0.2443
l8243 ppvdd2h1_s2sw 0.0489 or 132 ohms tg
l82AO pp0v575_s1_vddq1 0.1120
l8260 ppvdd_amph1_s2sw 0.3944
l8250 ppvdd_avemsr_awakesw 0.1139
c8162 pp3v3_s2 0.3692 cycling 0 - 1.5v
ct150 ppv3v3_aon 0.3604 3.3v stable
c8162 PP1V8_S2SW_CLVR_VDDC1_LDO 0.4759
c8165 PP0V8_S2_CLVR_VDDDIG 0.2241
c8180 pp1v5_aon_vcore_mpmu 0.3540 1.5v stable
r8317 pp1v8_aon 0.4122 1.8v stable
c8168 pp1v2_aon 0.5864 1.2v stable
c8152 pp4v9_vpump_mpmu 0.5671
rd650(pin 2) pp3v8_aon_mpmu 0.3125 slowly cycling 3.79v to 3.81v

l7860 pp0v855_s2sw_vddcio 0.1655
l7850 pvdd_soc_s1 0.0221 or 59 ohms
l7890 ppvdd_amph0_s2sw 0.3878
l7880 pp1v2_awake 0.2012
l7830 pp1v8_s2 0.2228 0.7v cycling
l7820 pp0v95_s2sw_vddcio 0.2942
l7800 pvdd_dcs_s1 0.1026 or 283.5 ohms
l7810 pp0v575_s1_vddq0 0.1098
l7843 ppvdd2h0_s2sw 0.0498 or 135 ohms
l78A0 ppvdd_disp_awakesw 0.0333 or 89.96 ohms
c7712 pp3v8_aon_spmu 0.3125
c7760 PP0V72_S2_VDDLOW 0.2255
c7763 PP1V2_AWAKESW_BLC 0.6493
c7768 PP1V2_AON_SPMU 0.6244
c7767 PP1V8_AON_SPMU 0.3536
c7780 PP1V5_AON_VCORE_SPMU 0.3525
c7752 PP4V9_VPUMP_SPMU 0.5662

[PickledOnion]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

For which component do you require the DIODE mode readings ?

PMIC ?

Yes u8100 would probably be a good start.

[mon2]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

For which component do you require the DIODE mode readings ?

PMIC ?

[PickledOnion]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

Can you share the exact netname used in the schematic? Unable to locate 3.3v_aon. Did you mean PPVIN_P3V8AON ?



If the power rails for the CD3218 ACE controllers have been met, the ACE controllers will function. They are stand alone devices with embedded microcontrollers. Review each of the power pins on these power delivery controllers.

So it appears that pp3v3_s2 is low on the input of the cd3218s. I have checked everywhere on this line for shorts there is none.

pp3v3_s2 is cycling from 0.5v to 1.9v.

pp3v3_s2 comes from u8100 pmic. I have also checked all the ldos on u8100 there are no shorts or burnt coils. Not sure where to go from here. Was going to try dfu but seems pointless if pp1v8_s2 and awake is also doing same thing(pulsing low)

I basicly need some good known diode readings from same board hence suggested sharing with the OP.

[PickledOnion]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

Can you share the exact netname used in the schematic? Unable to locate 3.3v_aon. Did you mean PPVIN_P3V8AON ?


If the power rails for the CD3218 ACE controllers have been met, the ACE controllers will function. They are stand alone devices with embedded microcontrollers. Review each of the power pins on these power delivery controllers.

Sorry it's PP3V3_AON

I will check the ace controllers and report bk.

[mon2]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

3.3v_aon is low and cycling?

Can you share the exact netname used in the schematic? Unable to locate 3.3v_aon. Did you mean PPVIN_P3V8AON ?

can charger come up to 20v even if my 3.3v_aon is low and cycling?

If the power rails for the CD3218 ACE controllers have been met, the ACE controllers will function. They are stand alone devices with embedded microcontrollers. Review each of the power pins on these power delivery controllers.

[PickledOnion]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

If you do not have 20v, review the LDO rails on the ACE controllers onboard. Each must be working to allow for the 20v power delivery contract to be selected.

What is the exact voltage to ground of PPBUS_AON ?

Thanks for suggestion,. So can charger come up to 20v even if my 3.3v_aon is low and cycling? Also PP5V_S2_MAIN
enable is low. The PPBUS_AON is 12.3v and stable.

[mon2]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

If you do not have 20v, review the LDO rails on the ACE controllers onboard. Each must be working to allow for the 20v power delivery contract to be selected.

What is the exact voltage to ground of PPBUS_AON ?

[PickledOnion]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

Thanks Yra98621. Did you have any luck with your repairs?

PMU_VDDHI doesn't seem wildly off, so I'm going to look for other causes..

I finally got the RAA209100B backlight buck-boost converter from China. Unfortunately after installing it the motherboard still doesn't work. There are some odd voltages on a few pins. Notably, the BL_PWR_EN signal from U8100 the master PMU to the backlight controller only comes up to about 0.5v, and it's not a very sharp transition. I'm wondering if this is a binary signal or not. Without the backlight converter, it didn't come up at all. Just had a small pulse on it.

So as is. The Macbook is trying to power on, but is resetting the power up sequence every second. It's not getting to the point where the SOC is loading the firmware as PP1v8_AWAKE never comes up properly, and this powers part of the EEPROM. PP1v8_AWAKE also powers most of the current and voltage sensor comparators. PP1v8_AWAKE is from a switch in u7100, the slave PMU. There is a note in the schematic saying that the switches in u7100 need the 4.9v ref on the VPUMP pin enabled. VPUMP is floating around 0.5v, not 4.9v. I'm not sure what enables this.. or if u7100 is bad... As the power up sequence resets, the USB-C charger stays at 5v and oscillates between 0.6 and 1W. Oddly installing the motherboard in the laptop it does the same thing, but the USB-C charger comes up to 20v. The battery doesn't charge, and it again oscillates between 0.6 to 1W. I'm currently trying to work out if the PMUs are resetting before VPUMP should come up, or because VPUMP's not coming up. There was a small amount of liquid damage around some of the ICs that measure the current on PP3V8_AON. These ICs don't depend on PP1v8_AWAKE, and could be giving a bad reading to the master PMU...

Hi Timp74

I am currently trying to rescue 820-02100 board that has been water damaged.

The backlight area is intact but similar water damage/corrosion around u5700 and isense.

magsafe is 5v, 0-04a - 0.10a and cycling. Cant get 20v on magsafe or usb-c.

I have stable ppbus aon, pp3v8_aon, ppv1v2_aon an,d ppv1v8_aon. However PP5V_S2_MAIN (and enable pin), p3v3_aon, pp1v2_s2 and pp1v8_s2sw and related rails are slowly climbing and dropping to zero and cycling (0v-0.5v-0v or 0v-1.5v-0v etc) roughly half the required rail voltage

It may be fruitless but we could both share diode readings of pmics and backlight etc to see if we can narrow down the issues.

A useful detail about the m1pro/max boards is they will only start up without battery and trackpad etc on the Mag safe connector only and will NOT on the USB-C ports. So best to only test on Mag safe. Thought i would share incase you didnt know.

Anyway I will post some diode readings later.

[Timp74]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

On 2442 i have PMU_VDDHI 2,56v PPBUS_AON 12,27

Thanks Yra98621. Did you have any luck with your repairs?

PMU_VDDHI doesn't seem wildly off, so I'm going to look for other causes..

I finally got the RAA209100B backlight buck-boost converter from China. Unfortunately after installing it the motherboard still doesn't work. There are some odd voltages on a few pins. Notably, the BL_PWR_EN signal from U8100 the master PMU to the backlight controller only comes up to about 0.5v, and it's not a very sharp transition. I'm wondering if this is a binary signal or not. Without the backlight converter, it didn't come up at all. Just had a small pulse on it.

So as is. The Macbook is trying to power on, but is resetting the power up sequence every second. It's not getting to the point where the SOC is loading the firmware as PP1v8_AWAKE never comes up properly, and this powers part of the EEPROM. PP1v8_AWAKE also powers most of the current and voltage sensor comparators. PP1v8_AWAKE is from a switch in u7100, the slave PMU. There is a note in the schematic saying that the switches in u7100 need the 4.9v ref on the VPUMP pin enabled. VPUMP is floating around 0.5v, not 4.9v. I'm not sure what enables this.. or if u7100 is bad... As the power up sequence resets, the USB-C charger stays at 5v and oscillates between 0.6 and 1W. Oddly installing the motherboard in the laptop it does the same thing, but the USB-C charger comes up to 20v. The battery doesn't charge, and it again oscillates between 0.6 to 1W. I'm currently trying to work out if the PMUs are resetting before VPUMP should come up, or because VPUMP's not coming up. There was a small amount of liquid damage around some of the ICs that measure the current on PP3V8_AON. These ICs don't depend on PP1v8_AWAKE, and could be giving a bad reading to the master PMU...

[yra98621]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

This is very interesting.. Can you add more NAND to change the size of the SSD?

Another possibility. R8170 was slightly corroded so PMU_VDDHI may be wrong. When PPBUS_AON is at 12.4 volts PMU_VDDHI is at 2.45 volts. Could anyone confirm this is the right ratio? There are two different options in the schematic, nether would give this ratio.

Also. The machine can't be loading anything from the EEPROMs as those need PP1V8_AWAKE. This power looping behaviour is probably because of the PMICs. Possibly a sensor out of range, although the majority of those also need PP1V8_AWAKE.. I'm running out of things to check.

On 2442 i have PMU_VDDHI 2,56v PPBUS_AON 12,27

[Timp74]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

Another possibility. R8170 was slightly corroded so PMU_VDDHI may be wrong. When PPBUS_AON is at 12.4 volts PMU_VDDHI is at 2.45 volts. Could anyone confirm this is the right ratio? There are two different options in the schematic, nether would give this ratio.

Also. The machine can't be loading anything from the EEPROMs as those need PP1V8_AWAKE. This power looping behaviour is probably because of the PMICs. Possibly a sensor out of range, although the majority of those also need PP1V8_AWAKE.. I'm running out of things to check.

[Timp74]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

I have given in and paid 50 bucks for a single chip from China. Will post update when it arrives and I try and install it.

I checked all buck and LDO outputs on the master and slave PMICs. All good. The only suspicious thing is that the vpump on the slave PMIC u7700 seems not to come up to 4.9 volts and has different diode/resistance to the master PMIC. This is needed for the switched outputs. So things like PP1v8_AWAKE. I'm assuming this is because it's programmed that way, not because there is a fault on U7700. I can't see how my attempts to fix the backlight controller could have damaged only a very specific part of u7700...

[yra98621]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

This is very interesting.. Can you add more NAND to change the size of the SSD?

Yes, you cand upgrade memory and ad more gb, in my iphone 13 i add 512gb from 128gb, and for example this is video for A2442 upgrading memory SSD, NAND

https://www.youtube.com/watch?v=yBwF3_x1Oog

[Timp74]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

Macs with m processors, you can change nand without any programmer, if i can do it then i reply here, same for iphone 12 and up, after you changed, you have to put it in dfu and reinstall the system.

This is very interesting.. Can you add more NAND to change the size of the SSD?

[yra98621]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

I hope you can fix it. I'm assuming the 'POWER ALIASES..' pages of the schematic list the power rails in a similar order to which they come up.. Like the 820-02100 I'm trying to fix has all rails up to PP1V8_AWAKE working(S2 rails are oscillating, but they come up to the correct voltage when high). PP1V8_AWAKE is only coming up to 0.7v and PP1V2_AWAKESW_BLC stays at 0v.

BTW. Have you successfully replaced NAND chips in Macbooks before? I thought they were factory programed for the machine they are in and can't be replaced/swapped.. That was written on a forum somewhere so may not be true..

Macs with m processors, you can change nand without any programmer, if i can do it then i reply here, same for iphone 12 and up, after you changed, you have to put it in dfu and reinstall the system.

[Timp74]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

i originally had problem with backlight not working just while lcd was working, so in any case i have to buy 209100B1 and try if it starts again.

Thanks for the tip on the _AON I will check them again

I hope you can fix it. I'm assuming the 'POWER ALIASES..' pages of the schematic list the power rails in a similar order to which they come up.. Like the 820-02100 I'm trying to fix has all rails up to PP1V8_AWAKE working(S2 rails are oscillating, but they come up to the correct voltage when high). PP1V8_AWAKE is only coming up to 0.7v and PP1V2_AWAKESW_BLC stays at 0v.

BTW. Have you successfully replaced NAND chips in Macbooks before? I thought they were factory programed for the machine they are in and can't be replaced/swapped.. That was written on a forum somewhere so may not be true..

[yra98621]

Re: 820-02100/02098 LCD Backlight Controller IC UP800..

Hi, Sounds like you need to work through the power rails again. If it's restarting like in the video, it may not have all _AON rails working.

Thanks for letting me know your opinion on the 209100B1 chip. Did you try turning your a2442 on when the chip was removed? There is an AliExpress seller that has the chips for 50 dollars. Which is still ridiculous, but if I knew it would fix the motherboard I would buy one.

i originally had problem with backlight not working just while lcd was working, so in any case i have to buy 209100B1 and try if it starts again.

Thanks for the tip on the _AON I will check them again