MacBook Air a1466 820-00165-a doesn’t start

[mgjini]

Re: MacBook Air a1466 820-00165-a doesn't start

What is the voltage value for your PPBUS_G3H ?

hi, sorry for late reply trying to find out and testing all the rails as much as i know, but now there is 2 rails missing here there is 0 on PP3V3_S4 and PP5V_S0

those 2 have no voltage, pbuss_g3h i have 8.54v

[mon2]

Re: MacBook Air a1466 820-00165-a doesn't start

pbus_g3h i have 8.54v

This is a good voltage and means that the SMC is communication over the SMBUS (I2C SDA & SCL) lines with U7100 to dial up the voltage to this value.

0 on PP3V3_S4

See page 58/75 of the schematics for a number of load switches (solid state relays).

See attached. PP3V3_S4 is passed through a load switch @ U8000.

Check that the voltage enters U8000 on pin # A2 & B2 - you can measure @ C8000. Voltage reading here ?

Check that the ENABLE for the load switch of U8000 is present on C2.

[mgjini]

Re: MacBook Air a1466 820-00165-a doesn't start

This is a good voltage and means that the SMC is communication over the SMBUS (I2C SDA & SCL) lines with U7100 to dial up the voltage to this value.



See page 58/75 of the schematics for a number of load switches (solid state relays).

See attached. PP3V3_S4 is passed through a load switch @ U8000.

Check that the voltage enters U8000 on pin # A2 & B2 - you can measure @ C8000. Voltage reading here ?

Check that the ENABLE for the load switch of U8000 is present on C2.

i measured u8000 and 3.3v is entering, when i am meassuing at the back as per picture S4_PWER_EN Q2090 I am getting 0v

[mon2]

Re: MacBook Air a1466 820-00165-a doesn't start

See attached.

Measure the voltage on EACH side of R8115. This is the resistor that passes the voltage through for this enable signal.

perhaps R8115 is damaged but check with the voltage on each pin of this part.

[mgjini]

Re: MacBook Air a1466 820-00165-a doesn't start

also r4410 r4411 c4330 u4430 those measure 2.7v so something is pulling down this rail

[mgjini]

Re: MacBook Air a1466 820-00165-a doesn't start

See attached.

Measure the voltage on EACH side of R8115. This is the resistor that passes the voltage through for this enable signal.

perhaps R8115 is damaged but check with the voltage on each pin of this part.

r8115 is giving 0v but measuring on oms this gives 776 oms but because i have spare boards this measure 0.98 k oms , i replaced this with a spare board part but still same results 0v and same oms measurements

[mon2]

Re: MacBook Air a1466 820-00165-a doesn't start

R8115 is supposed to be 0 ohms. Can you confirm this ?

[mgjini]

Re: MacBook Air a1466 820-00165-a doesn't start

R8115 is supposed to be 0 ohms. Can you confirm this ?

sorry yes it is 0 oms as i meassured when board was hot

[mon2]

Re: MacBook Air a1466 820-00165-a doesn't start

also r4410 r4411 c4330 u4430 those measure 2.7v so something is pulling down this rail

This is good. I think you have a broken connection since the rail is high at another point of the same trace.

Remove all power. Remove the battery.

Then place your meter in resistance scale (2k is ok).

Place one meter probe where you can see 2v7 and the other meter probe where you do not see the voltage present (R8115 is good since we know it is 0 volts).

What is the resistance between these 2 points ? Guessing it will be OL = over limit = open circuit ?

Just confirm that the rail labels are the same between the 2 points being tested. That is, according to the schematic, if you see 2v7 on one point, then you should see the same voltage at another point of the same rail. If not, then there is a broken trace / broken via causing this fault.

Confirm it to move forward. If you are 100% sure this is the case, then you can do the following:

a) use the resistance mode again to check if there is a heavy load on R8115 to ground. If the load is not a low resistance then proceed to solder a wire from where you can see 2v7 and apply to to a convenient point where this rail is 0V.

b) as long as there is not a very low resistance to ground on R8115 then it is ok to 'fix' the broken trace / via with a wire jumping the points.

After such a repair but before turning on any power, check the resistance to ground again. Be sure there is no low resistance reading. Then power up and you should see the 2v7 travel through this rail.

Just some ideas but believe it is all logical to repair as noted. Always double check your work before powering on.

[mgjini]

Re: MacBook Air a1466 820-00165-a doesn't start

This is good. I think you have a broken connection since the rail is high at another point of the same trace.

Remove all power. Remove the battery.

Then place your meter in resistance scale (2k is ok).

Place one meter probe where you can see 2v7 and the other meter probe where you do not see the voltage present (R8115 is good since we know it is 0 volts).

What is the resistance between these 2 points ? Guessing it will be OL = over limit = open circuit ?

Just confirm that the rail labels are the same between the 2 points being tested. That is, according to the schematic, if you see 2v7 on one point, then you should see the same voltage at another point of the same rail. If not, then there is a broken trace / broken via causing this fault.

Confirm it to move forward. If you are 100% sure this is the case, then you can do the following:

a) use the resistance mode again to check if there is a heavy load on R8115 to ground. If the load is not a low resistance then proceed to solder a wire from where you can see 2v7 and apply to to a convenient point where this rail is 0V.

b) as long as there is not a very low resistance to ground on R8115 then it is ok to 'fix' the broken trace / via with a wire jumping the points.

After such a repair but before turning on any power, check the resistance to ground again. Be sure there is no low resistance reading. Then power up and you should see the 2v7 travel through this rail.

Just some ideas but believe it is all logical to repair as noted. Always double check your work before powering on.

so the resistance between r4411 and r8115 it shows 788 oms, do i proceed with the wire, and i am really sorry to waist your time and thanks

[kalilinux25]

Re: MacBook Air a1466 820-00165-a doesn't start

1) pp5v_s4rs3 is generated by U7501.

2) power down, meter in resistance mode. Black lead on ground.

Red lead on L7520, pin 2 - what is the resistance in ohms ?

3) Meter in volts mode, black lead on ground.

Red lead on R7551 = P5VS4RS3_EN. Reading in volts ?

4) Meter in volts mode, black lead on ground.

Red lead on PP3V3_S5_REG_R, L7560 - pin 2 - reading in volts ?

My board will just take 25MIALLMP

I test voltage on the L7520 every second it goes 0v to 2.2vv to 0v again

Missing PPV3V3_S0
R7551 no voltage

Im new in the macbooks sorry

[mon2]

Re: MacBook Air a1466 820-00165-a doesn't start

Test the voltage of ALL_SYS_PWRGD.

Is it pulsing? Post the measurement.

[kalilinux25]

Re: MacBook Air a1466 820-00165-a doesn't start

Test the voltage of ALL_SYS_PWRGD.

Is it pulsing? Post the measurement.

yes, 0v to 1.2v

[kalilinux25]

Re: MacBook Air a1466 820-00165-a doesn't start

yes, 0v to 1.2v

u5110-
1- 3.4v
6- 3.4v
5- 3.3v

r5100
1-3.4v
2-3.3v

pp5v_s5 - 5v not stable 4.9
pp3v_s5 - 3.3v stable

L3095V - 3.3V

Q3005-8.0V
PM_SLP_S4_L - 0V

[kalilinux25]

Re: MacBook Air a1466 820-00165-a doesn't start

Review these very good articles on the A1466:

https://repair.wiki/w/A1466_2013-201...9D_MacBook_Air

https://www.it-tech.com.au/mac-q-a/m...-up-sequences/

https://logi.wiki/index.php/Power_Rail_List

If you remove R8111 and PM_SLP_S4_L comes back, it's most likely dead CPU, check for corrosion around RAM area and if none then most likely dead CP.

I think my cpu is dead? cause the PM_SLP_S4_L present when I tried t o remove the R8111
I put back the R8111 and test P5VS4RS3_EN_R is pulsing

[reformatt]

Re: MacBook Air a1466 820-00165-a doesn't start

I find it hard to follow this thread. So start with the basics.

Check the resistance to ground on each coil, especially L7630. In my experience, anything under 100 ohms for the PP1V05_S0 rail, the PCH is usually toast and the board is a donor.

PP3V42_G3H, PPBUS_G3H and PP3V3_S5 should always be present regardless of power state. With 165 boards, it's important to check power supplies on each coil when you initially plug in as they can come up initially then disappear. If you get Vcore = 1.8V, the fault isnt power supply related per se and your problem is elsewhere.

So need to know whether you get any pulsing at all up to Vcore, if it's once, twice or cycling.

[kalilinux25]

Re: MacBook Air a1466 820-00165-a doesn't start

I find it hard to follow this thread. So start with the basics.

Check the resistance to ground on each coil, especially L7630. In my experience, anything under 100 ohms for the PP1V05_S0 rail, the PCH is usually toast and the board is a donor.

PP3V42_G3H, PPBUS_G3H and PP3V3_S5 should always be present regardless of power state. With 165 boards, it's important to check power supplies on each coil when you initially plug in as they can come up initially then disappear. If you get Vcore = 1.8V, the fault isnt power supply related per se and your problem is elsewhere.

So need to know whether you get any pulsing at all up to Vcore, if it's once, twice or cycling.

its cycling sir

[reformatt]

Re: MacBook Air a1466 820-00165-a doesn't start

So you are getting all voltages up to Vcore, and they are cycling correct? That's a good thing if so since its usually EFI related. Use a known good code for U6100 (I posted one a month or two back for the 165 board), and check that all termination resistors are intact. Also check continuity for the resistor junctions around U6100 that go to the CPU.

[piernov]

Re: MacBook Air a1466 820-00165-a doesn't start

If you remove R8111 and PM_SLP_S4_L comes back, it's most likely dead CPU, check for corrosion around RAM area and if none then most likely dead CP.

Wrong, just prevents reaching S0 state and inhibits pulsing, pulsing can be caused by a lot of different reasons. (dead CPU can be one of them but not the only one)

[kalilinux25]

Re: MacBook Air a1466 820-00165-a doesn't start

Wrong, just prevents reaching S0 state and inhibits pulsing, pulsing can be caused by a lot of different reasons. (dead CPU can be one of them but not the only one)

What other parts do I need to check also sir?