-
For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.Subscribe Now
[HELP]a1990 820-01041 NOBOOT, STRANGE!
- Thread starter phantom
- Start date
Do you have 3.3V at both L6960 and L7660?
Check UPC_PMU_RESET signal.
Also check all U7800's SLPS2R and AWAKE voltages; the small coils around it.
Check UPC_PMU_RESET signal.
Also check all U7800's SLPS2R and AWAKE voltages; the small coils around it.
CC1/2 pins change the voltage, according which direction is connected the charger on the corresponding port.
Check diode mode on all big coils and compare with good board, or refference table.
Don't forget L9080/580.
Try to put the machine in DFU using wire method.
logi.wiki
Check diode mode on all big coils and compare with good board, or refference table.
Don't forget L9080/580.
Try to put the machine in DFU using wire method.
DFU Mode Restore (Macs) - LogiWiki
We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area
you said to check in diode mode, but reference table is in ohm scaleCC1/2 pins change the voltage, according which direction is connected the charger on the corresponding port.
Check diode mode on all big coils and compare with good board, or refference table.
Don't forget L9080/580.
Try to put the machine in DFU using wire method.
DFU Mode Restore (Macs) - LogiWiki
We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area
l7410 and l7420 i have 0,2ohm and 0,002 in diode mode
l9080/580 seems fine
Last edited:
i've done a jumper on swk003 and connected the left port nearest to track pad to my air m1...nothing happen...
i remember you what i 've discovered some post ago:
"
if i connect the upper left or right port to my mac m1, i receive the message
"impossible to use accessory"
if i try to connect the others two ports, nothing happen
i remember you what i 've discovered some post ago:
"
if i connect the upper left or right port to my mac m1, i receive the message
"impossible to use accessory"
if i try to connect the others two ports, nothing happen
"reference table is in ohm scale"
???
v for voltage readings
d for diode mode readings
Where did you see ohm values mentioned?
If machine is not recognized into DFU, then probably bad T2 chip...
???
v for voltage readings
d for diode mode readings
Where did you see ohm values mentioned?
If machine is not recognized into DFU, then probably bad T2 chip...
Screenshot-2023-10-31-alle-21-32-08 hosted at ImgBB
Image Screenshot-2023-10-31-alle-21-32-08 hosted in ImgBB
ibb.co
reference table for coil is in ohm not diode!
so you think there is a t2 problem??
can't do anything else?
Do you know what these values for coils mean???
Don't get confused man.
Internal specifications of the coils, have nothing to see with diode mode (or ohm resistance) to ground.
If T2 gets all SLPS2R and AWAKE required voltage, it should go into DFU.
Be sure to use all steps to enter DFU correctly.
Don't get confused man.
Internal specifications of the coils, have nothing to see with diode mode (or ohm resistance) to ground.
If T2 gets all SLPS2R and AWAKE required voltage, it should go into DFU.
Be sure to use all steps to enter DFU correctly.
yes sure, but you have asked me to check all coils in diode mode using referance table...in the reference table there is no reference to diode mode for the coils, but for the lines!!!
"If T2 gets all SLPS2R and AWAKE required voltage"
i don't know this voltages....could you help me?
3,3 on l6960 and 7660
0v on r6941 (UPC_PMU_RESET)
you said "Be sure to use all steps to enter DFU correctly"
if i use the jumper, the mac should be directly in dfu right?
"If T2 gets all SLPS2R and AWAKE required voltage"
i don't know this voltages....could you help me?
3,3 on l6960 and 7660
0v on r6941 (UPC_PMU_RESET)
you said "Be sure to use all steps to enter DFU correctly"
if i use the jumper, the mac should be directly in dfu right?
"asked me to check all coils in diode mode"
We use the coils as test points for the secondary power supplies output!
What do you expect to get in diode mode (or ohm scale), measuring between a coil pins?
The coil is a short in DC mode!
Personally I prefer to solder a small switch (with 5-10cm wires) over the force DFU pads.
Machine should enter to DFU after 5-10s, starting with the switch closed.
If not, force it off (power button) and try again.
Sometime I got in DFU maintaining the switch closed when i forced the machine off.
I fight with an A1949 two days until I got in DFU.
This is not as easy as you think.
Apple did a "good job", for its interest.
Some peoples claimed they couldn't get in DFU with original Apple cables.
Even the macOS installed in the host machine may impede to detect the target machine correctly with AC2.
"0v on r6941 (UPC_PMU_RESET)"
Good enough, we don't want the machine in reset state.
We use the coils as test points for the secondary power supplies output!
What do you expect to get in diode mode (or ohm scale), measuring between a coil pins?
The coil is a short in DC mode!
Personally I prefer to solder a small switch (with 5-10cm wires) over the force DFU pads.
Machine should enter to DFU after 5-10s, starting with the switch closed.
If not, force it off (power button) and try again.
Sometime I got in DFU maintaining the switch closed when i forced the machine off.
I fight with an A1949 two days until I got in DFU.
This is not as easy as you think.
Apple did a "good job", for its interest.
Some peoples claimed they couldn't get in DFU with original Apple cables.
Even the macOS installed in the host machine may impede to detect the target machine correctly with AC2.
"0v on r6941 (UPC_PMU_RESET)"
Good enough, we don't want the machine in reset state.
ok just a question....
like i said , i have changed all 4 cd3215...but they where used...
now i would like to mount 4 brand new ic
could i mount 2 at times?
i mean ta / tb...test if ampmeter power on
then xa/xb and test?
ps do you know where can i find resistence to ground for the pads unders cd3215? thanks
like i said , i have changed all 4 cd3215...but they where used...
now i would like to mount 4 brand new ic
could i mount 2 at times?
i mean ta / tb...test if ampmeter power on
then xa/xb and test?
ps do you know where can i find resistence to ground for the pads unders cd3215? thanks
Last edited:
You should get similar readings on 01814, even 00850 boards; in the USB-C areas.
Be aware to solder correct CD3215 chips, with the same code termination; C00, A12, B03 not interchangeable.
You can solder and test one by one.
Be aware to solder correct CD3215 chips, with the same code termination; C00, A12, B03 not interchangeable.
You can solder and test one by one.
so i have changed again all 4 ic with 4 brand new.
i have check for short every pad, before soldering each ic.
i have soldered the first and checked with ampmetere [email protected]
i have soldered the second and checked with ampmetere [email protected]
i have soldered the third and checked with ampmeter [email protected]
i have soldered the fourth and checked with ampmetere [email protected]
so i don't know what to think or do..
please help me
NO LUCK WITH DFU MODE...
no fan spin no dfu nothing ...
i have check for short every pad, before soldering each ic.
i have soldered the first and checked with ampmetere [email protected]
i have soldered the second and checked with ampmetere [email protected]
i have soldered the third and checked with ampmeter [email protected]
i have soldered the fourth and checked with ampmetere [email protected]
so i don't know what to think or do..
please help me
NO LUCK WITH DFU MODE...
no fan spin no dfu nothing ...
Last edited:
Did you solder the CD3215 chips with correct termination?
C00, A12, B03 are not interchangeable.
If U7800 delivers all required SLPS2R and AWAKE voltages, board should enter DFU.
If not, there is a problem with T2 chip or communication through corresponding DFU port.
If you replaced all CD3215 chips and checked all ports, probably T2 is the culprit.
C00, A12, B03 are not interchangeable.
If U7800 delivers all required SLPS2R and AWAKE voltages, board should enter DFU.
If not, there is a problem with T2 chip or communication through corresponding DFU port.
If you replaced all CD3215 chips and checked all ports, probably T2 is the culprit.