A1534 820-00045 no power

[hgoncalves]

Hi,

I have an A1534 820-00045 that has no power. The ampmeter stays black, and I have no PPVBUS_E85 nither PPDCIN_E85_SS voltages. Nither seams to be shorted (0.555 on diode reading).

F4700 seams to be ok.

Already tried a known good DCIN cable, with same result.

Can you help?

 

[2informaticos]

Start checking diode mode to ground on CC1/2 lines.
Also compare the value at 3V0_AON with good board.

 

[hgoncalves]

Diode readings:

E85_CC1 = 0.554
E85_CC2 = 0.014

I don't have a good board of this model, but it seams that CC2 is shorted. Shall i inject voltage on it, or replace U4700??

 

[2informaticos]

Is not pure short, to heat something there.
Replace the chip, is classic issue.

 

[hgoncalves]

I've replace U4700, and the short on CC2 has gone (0.555 on diode reading). However, I have the same behavier.

 

[2informaticos]

Post diode mode to ground at 3V0_AON.
May need to change U4780 and/or U4701 too.

 

[hgoncalves]

Diode on 3V0_AON = 0.333

 

[2informaticos]

Looks too low.
Change U4780 first.

 

[hgoncalves]

I've replaced U4780 and U4701, but same behavier. Diode on 3V0_AON is 0.329.
I notice now that C4750 PPDCIN_E85_SS seams to be a bit oxidized and corroded. It wasen't shorted, but i removed. Can it be related?

 

[2informaticos]

Diode mode on 3V0_AON should be higher than 0.400.

 

[hgoncalves]

Replaced again U4700 but same thing.
There are a lot of components with 3V0_AON. Shal I inject some voltage to figure out if something gets hotter?

 

[2informaticos]

Voltage injection cannot help here.

CD3215 chip used is good for sure?
Check diode mode to ground on its LDOs.

 

[hgoncalves]

Sorry, for the stupid question, but what CD3125? I can't find it on this board

 

[2informaticos]

Sorry for error; there was another thread with 00244 board.

You may have problem with U7000 in this case.

 

[hgoncalves]

Sorry, but I can't find it also. I replaced U7100, but same result. No power

 

[2informaticos]

U7100, is true.
What is actual diode mode to ground for 3V_AON?

 

[hgoncalves]

Diode on PP3VR3V0_AON = 0.324

 

[2informaticos]

Still low value.
Some chip must be affected there.
Try another U4700.

 

[hgoncalves]

Replaced other U4700 but same result.
PP3VR3V0_AON = 0.328

 

[2informaticos]

You don't get any voltage at F4700?
What voltage do you get at CC1/2 lines?
Did you try another charger?