Voltages:
Vcore - 1V -> 0850V -> 0V
Vmem - 1.355V -> 0V
VDDCI - 0.820V -> 0V
Vsoc - 0.882V -> 0V
3.3V - 3.3V stays
12V - 12V stays
1.8V - 1.8V -> 0.570V
5V - 5V stays​
karoliens
Member
Last Activity: Today, 09:19 PM
Joined: 12-12-2019
Location: Aarhus
-
RX 6900 XT no image
Hi,
I am working on GIGABYTE RX 6900 XT Gaming OC GPU that does not show any image.
When I power on the PC ARGB is lit on the GPU, fans spin for couple of seconds and stop and VGA LED on the motherboard stays on.
So far I have tested if I am getting 12V from the PSU on all three of the 8-pin connectors.
Next I checked resistance to ground:
Vcore - 0.4 Ohm
Vmem - 21.7 Ohm
VDDCI - 14.7 Ohm
Vsoc - 1.4 Ohm
3.3V - 6k Ohm
12V - 1.3k Ohm
From what I have read these reading are OK?
... -
Re: 820-01700 PPVCC_S0_CPU normal resistance to ground/diode reading?
Thank you for explanation.Leave a comment:
-
Re: 820-01700 PPVCC_S0_CPU normal resistance to ground/diode reading?
So you just cut the end of non-genuine USB-C brick and connect it to PSU? I suppose I could also use USB-C ammeter. I've see Louis using one for troubleshooting....Leave a comment:
-
Re: 820-01700 PPVCC_S0_CPU normal resistance to ground/diode reading?
Thank you for a quick reply. I've read that thread already but I was hoping maybe someone remembers from the top of their head normal reading on that rail.
I'll hook it up to the power supply and I see what it shows. With older MacBooks that use MagSafe1 and MaSafe2 I've cut the cable with lightning connector ant connected it to the power supply for troubleshooting.
Do I need to buy genuine USB-C charging brick to do the same for these newer models as well? :smile...Leave a comment:
-
820-01700 PPVCC_S0_CPU normal resistance to ground/diode reading?
I am working on this board that has some water damage though not around this rail but I measured it anyway to rule out that CPU is not fried.
Resistance to ground on PPVCC_S0_CPU rail is 2Ohm and in diode mode it shows 0V.
What is the normal reading on that rail?
TIA -
How to test iPad charging dock
Hi,
Any way to test iPad dock and Tristar IC after dock replacement without Tristar tester?
I have only the board, no battery. -
Re: MacBook Pro 1502 820-4924 Keyboard and Trackpad do not work
There's no liquid spill, board is clean. Before charger was messed up keyboard and trackpad were working. SSD was working.Leave a comment:
-
MacBook Pro 1502 820-4924 Keyboard and Trackpad do not work
Hi,
I have 820-4924 board that has keyboard and trackpad problem. I suspect it is logic board issue.
I was told that in attempt to repair MagSafe charger wires were mixed up and therefore it does not power on.
Using PSU machine starts and is stuck at the folder with question mark. If I put USB drive with macOS it start in the installation wizard, but keyboard and trackpad do not work.
I checked voltages at the keyboard and trackpad connector:
PP3V3_S4_TPAD 3.3V
PP3V42_G3H_TPAD 3.42V
WS_KBD_ONOFF_L 3.42V... -
Re: 820-00165-A No Power/Fan, draws 0.027A on PS, all S0 state rails 0V
It's definitely a rabbit hole this one. It's quite difficult to troubleshoot when there's no hints whatsoever and board is clean. Nonetheless thank you for the effort guys.
P.S. I've attached photos of the SMC (I removed underfill intentionally to check underneath), SPI ROM, J6100 areas....Leave a comment:
-
Re: 820-00165-A No Power/Fan, draws 0.027A on PS, all S0 state rails 0V
PCH_CLK32K_RTCX1 is 32 kHz
Other lines are 25 MHz and I don't think my multimeter is capable of measuring that. In the manual it says 5.00 - 500 kHz (3Vpeak)....Leave a comment:
-
Re: 820-00165-A No Power/Fan, draws 0.027A on PS, all S0 state rails 0V
I'm pretty sure that I've checked that before, but here are the results.
Resistance to ground:
PP3V3_S4 57.25 kOhm
PP5V_S4RS3 2 MOhm
PP3V3_S3 1.2 MOhm
PP3V3_S4SW_SNS 1.6 MOhm
PP1V8_S3 53 kOhm
PP1V2_S3 413 Ohm...Leave a comment:
-
Re: 820-00165-A No Power/Fan, draws 0.027A on PS, all S0 state rails 0V
First of all thank you for your effort helping me. I mostly fixing iPhone logic boards so MacBooks are still fresh for me.
PPVCC_S0_CPU jumps to 1.8V and goes to 0V.
Resistance between pins 17/18 3.2 Ohm 27/28 20.1 Ohm.
SMC_ONOFF_L is shorted and I plug in MagSafe there's no light at all. And when I remove short there's still no light but fan spins two times and stops....Leave a comment:
-
Re: 820-00165-A No Power/Fan, draws 0.027A on PS, all S0 state rails 0V
When I plug in MagSafe PM_SLP_S5_L jumps to 3.318V and then goes to 0V.
I am using Brymen BM257s....Leave a comment:
-
Re: 820-00165-A No Power/Fan, draws 0.027A on PS, all S0 state rails 0V
Thank you for a quick reply.
I am using Power Supply for troubleshooting with genuine cut MagSafe2 cable and the light is amber. When connected inside the housing the light is green.
As I mentioned the board looks as it was run through ultrasonic cleaner so it makes difficult to see any corrosion as the board looks clean.
Areas around SMC, SPI ROM, J6100, U1950 seem to be clean, but as I mentioned it is most likely had ultrasonic cleaning before so...Leave a comment:
-
820-00165-A No Power/Fan, draws 0.027A on PS, all S0 state rails 0V
I hit a wall with this one. As per title No power/fan spin when connected to PS.
And to make things even more difficult it looks that the board was run through ultrasonic cleaner so I can not find any suspects.
I went through all power rails and all the S0 state rails are not present.
V
PPBUS_G3H 8.58
PPBUS_S5_HS_COMPUTING_ISNS 8.59
PPBUS_S5_HS_OTHER_ISNS 8.59
PPDCIN_G3H_ISOL 18.50
PPDCIN_G3H 18.50
PP3V42_G3H 3.417
PPVRTC_G3H 3.320
PP5V_S5 5.022
PP5V_S4RS3 0
PP5V_S0 0.048
... -
Re: New Members - please post your introductions here
Hi guys,
I've recently joined this great forum when I was searching for MacBook schematics. I've been working as technician for 5 years now. I began with basic repairs and it's been 2 years since I'm doing iPhone/Android component level repairs.Still quite new when it comes to MacBook logic board repairs.Leave a comment:
No activity results to display
Leave a comment: