(347) 552-2258 [email protected]

A1989 820-00850-A with no power.

H

hgoncalves

Active member
Hi.

I have an A1989 820-00850-A with no power.

It has only 5V on ampmeter.

PP1V1_UPC_XA_LDO_BMC was shorted and so I've replaced U3100.

However, I still have only 5V on ampmeter.

U3100:
PP3V3_UPC_XA_LDO = 3.287V
PP1V8_UPC_XA_LDOA = 1.810V
PP1V8_UPC_XA_LDOD = 1.798V
PP1V1_UPC_XA_LDO_BMC = 0V and 0.525 on diode reading
USBC_XA_CC1 = 0V and 0.561 on diode reading
USBC_XA_CC2 = 1.682V

U3200:
PP3V3_UPC_XB_LDO = 3.3V
PP1V8_UPC_XB_LDOA = 1.8V
PP1V8_UPC_XB_LDOD = 1.8V
PP1V1_UPC_XB_LDO_BMC = 0V and 0.483 on diode reading
USBC_XB_CC1 = 1.605V
USBC_XB_CC2 = 0V and 01.565 on diode reading

UB300:
PP3V3_UPC_TA_LDO = 3.3V
PP1V8_UPC_TA_LDOA = 1.8V
PP1V8_UPC_TA_LDOD = 1.8V
PP1V1_UPC_TA_LDO_BMC = 0V and 0.749 on diode reading
USBC_TA_CC1 = 0V and 0.590 on diode reading
USBC_TA_CC2 = 1.7V

UB400:
PP3V3_UPC_TB_LDO = 3.3V
PP1V8_UPC_TB_LDOA = 1.8V
PP1V8_UPC_TB_LDOD = 1.8V
PP1V1_UPC_TB_LDO_BMC = 0V and 0.482 on diode reading
USBC_TB_CC1 = 1.615V
USBC_TB_CC2 = 0V and 0.595 on diode reading

Can you help?
 
Last edited:
H

hgoncalves

Active member
Hi,

I've replaced UB300, and now on PP1V1_UPC_TA_LDO_BMC (UB300) I have 1.1V. On all others CD3215, 1V1 LDO's have 0V, and arround 0.500 on diode readings.

Still only 5V on ampmeter
 
H

hgoncalves

Active member
Hi.

I've tried with a charged battery, but same problem. Only 5V.

I think that the problem is 1V1 LDO has no voltage (even when the ports are powered) on 3 of the usb-c ports.

Only in UB300 I have 1.1V on 1V1 LDO
 
Last edited:
2informaticos

2informaticos

Administrator
Staff member
So the board doesn't turn on with charged battery?

You should try changing the CD3215 chips on the ports with missing 1V1 LDO.
 
Last edited:
H

hgoncalves

Active member
Hi.

The board doesn't turn on with a charged battery.

I've already replaced two U3100 just to be sure, but it still has the same behavior (no power on, and 0V on 1V1 LDO).

Should I replace the other CD3215 anyway? Can it be one of the other CD3215 causing the issue?
 
H

hgoncalves

Active member
Hi.

Yes, all other CD3215 LDOs seams to be OK:

U3100:
PP3V3_UPC_XA_LDO = 3.287V
PP1V8_UPC_XA_LDOA = 1.810V
PP1V8_UPC_XA_LDOD = 1.795V

U3200:
PP3V3_UPC_XB_LDO = 3.3V
PP1V8_UPC_XB_LDOA = 1.8V
PP1V8_UPC_XB_LDOD = 1.792V

UB300:
PP3V3_UPC_TA_LDO = 3.218V
PP1V8_UPC_TA_LDOA = 1.8V
PP1V8_UPC_TA_LDOD = 1.795V

UB400:
PP3V3_UPC_TB_LDO = 3.276V
PP1V8_UPC_TB_LDOA = 1.790V
PP1V8_UPC_TB_LDOD = 1.8V
 
H

hgoncalves

Active member
Hi.

I've flashed the original Rom,s and now I have again 1V1 LDO on UB300 only.

Any other idea?
 
Last edited:
H

hgoncalves

Active member
Hi.

After replacing again all CD3215, and rebuild some tracks to his pads, the Mac started to power on again.

However, none of the ports recognize the charger, and the battery isen't recognized.

Can you help?
 
You must log in or register to reply here.
Top