MacBook Air a1370 only runs on the charger

[crea2k]

So im testing PPDCIN_S5_CHGR on Q7080 and am getting 14.5 volts but it should be 18.5v according to the schematic. If I measure resistance to ground on that line I get 040.0kohm , but without another board to compare to that is meaningless, all we know what is happening so far is the voltage isnt what it should be on that line, so il see if I can find any filters or something on that line. Iv tried two charger and two dc in boards and get that same 14.5-14.8volts at the dc in board connector.

[crea2k]

Here are some voltages from around ISL6250 :

PP3V42_G3H
3.39v

CHGR_CSI_P
14.50v

CHGR_CSI_N
14.45v

CHGR_BOOT
12.89v

CHGR_UGATE
10.95

PP5V1_CHGR_VDDP
5.05v

CHGR_CSO_N
8.36v

CHGR_CSO_P
8.36v

SMC_BC_ACOK
2.97v

CHGR_RST_L
3.3v

CHGR_VNEG_R
1.3v

CHGR_VCOMP_R
1.3v

CHGR_DCIN
14.2v

CHGR_ACIN
3.74v

CHGR_ICOMP
1.54v

CHGR_CELL
0v

CHGR_VCOMP
1.52v

CHGR_VCOMP_R
1.44v

tested :
R5420 = good
R7085 = 0.469M
R7080 = good
R7081 = good
R7005 = good

Voltage @ R7005 = 14.1v & 14.35v
Voltage @ R7080 = 14.69v & 5.57v
Voltage @ R7001 = 5.1v & 5.05v
Voltage @ R7085 = 14.62v & 5.7v
Voltage @ R5420 = 0.061v & 0.061v

[crea2k]

Iv got a feeling this could be the customers crappy battery causing half of this. I know the dc in board looked like garbage as it was water damaged and had components missing. So that was replaced and the voltage appears to be getting through ok now. Iv ruled the isl chip out as changed that. Iv just checked the customers battery and it's zero volts at the terminals. If I measure the cell tabs it's 1.9v so it looks like the bms under voltage protection has kicked in. I tried charging it by dtps and it wasn't having any of it, which explains why it was saying to replace the battery as the bms was probably telling the motherboard the battery was below minimum cell voltage (usually 3 volts on a lithium battery).
So have ordered another in, so will see how that goes.