820-3332 board retina 15" , no ppbus 12.6v, only 1.2v, green light ok

[turbo]

this 820-3332 retina 15" board don't have any ppbus g3h!, green is on, i changed ISL6259 chip, still no luck only 1.2 V in ppbus. also dont see any short to ground

any advice!!!

im attaching isl pin voltage pls chk

1	0		CHGR_AGATE
2	16.48		CHGR_DCIN
3	4		CHGR_ACIN
4	3.32		CHGR_VFRQ
5	0.23		CHGR_ICOMP
6	3.3		CHGR_CELL
7	0.72		CHGR_VCOMP
8	0.27		CHGR_VNEG
9	2.25		CHGR_AMON
10	3.35		SMBUS_CHGR_SDA
11	3.35		SMBUS_CHGR_SCL
12	3.35		VHST
13	3.32		CHGR_RST_L
14	3.2		CHGR_ACOK
15	0.05		CHGR_BMON
16	1.7		CHGR_BGATE
17	1.61		CHGR_CSO_N
18	1.61		CHGR_CSO_P
19	5.4		vdd
20	5.4		vddp
21	0		CHGR_LGATE
22	0		GND
23	1.6		CHGR_PHASE
24	1.6		CHGR_UGATE
25	5		CHGR_BOOT
26	0.001		CHGR_SGATE
27	16.13		CHGR_CSI_N
28	16.66		CHGR_CSI_N

 

[larossmann]

Check resistance of R7005

Check resistance between pins 27/28 of U7000, should be 20.020 ohms

Check resistance between pins 17/18 of U7000, should be 2.2005 ohms

 

[turbo]

wow louis you are seriously smart. it was r7021 and r7022, notw ppbus_g3h is good 12.6 v

now no 5v, rail. , u7201 making 3.3v but no 5v, pin 4 =P5VS4_EN is missing ..... then i found PM_SLP_S5_L is missing.. for missing PM_SLP_S5_L ... what do i chk ? thanks in advance. which rail power the u1800?? .

 

[larossmann]

is rtc voltage present? need more hints!

 

[turbo]

here is u2600 all pin value

3.3
3.3
0
0.6
0
0
0
0.08
0
0
0
0.22
3.3
0
0
0

,

 

[aprendiz]

RTC voltage = PPVRTC_G3_OUT......... Also check R1800-R1803 should have about 3V each side and check SYSCLK_CLK32K_RTC with oscilloscope 32Khz.....