Dell V3450 no power from adapter, Battery ok.

[nazrul145]

Hi there, Please help me about this topics.
Its dell vostro 3450. Power from battery ok but it not run from adapter.
Its PL9 and Pl10 have no voltage when charger connected.
I replaced isl6237 instead of RT8206B.
Only Isl6237 LDO 5V out. But no 3.3v and 5v.
ISL6237
pin14=0v
pin27=4.9V.

output coil 0v.
Please help for whats wrong.
attached schematic here.
Thanks advance.

[ktmmotocross]

Re: Dell V3450 no power from adapter, Battery ok.

do u have signal for EN1 and EN2?

[nazrul145]

Re: Dell V3450 no power from adapter, Battery ok.

pu5 on1 0v and on2 4.9V

[selldoor]

Re: Dell V3450 no power from adapter, Battery ok.

Tested the adapter? with a load?

[alihomee]

Re: Dell V3450 no power from adapter, Battery ok.

hi bro plz change charging chip then will be ok i think 8731AE they use for this model

[nazrul145]

Re: Dell V3450 no power from adapter, Battery ok.

thanks alihomee, ist charging chip isl88731c and i already change it, no power.

[Ramee]

Re: Dell V3450 no power from adapter, Battery ok.

agreed with selldoor..

Check a/c adapter, but load it up, see if the voltage drop.

[nazrul145]

Re: Dell V3450 no power from adapter, Battery ok.

i already check different ac adapter.
problem with ac adapter 5v enable voltage not come from sio, i mean alwon# so that 3.3v and 5v not come to coil.

[whaldsz]

Re: Dell V3450 no power from adapter, Battery ok.

what do you get at pin 13 of PU1?

[BCConnectionLLC]

Re: Dell V3450 no power from adapter, Battery ok.

If you get voltage out on PL3 then no need to check the ACOK pin. If ACOK isnt there the chip wont output the voltage.

Always check the main output of the chip before going pin to pin.

[nazrul145]

Re: Dell V3450 no power from adapter, Battery ok.

PU1 pin 13=3.1V, ACAV_IN signal should go SIO IT8518e pin no 21. But SIO Pin21 is 0V.

[BCConnectionLLC]

Re: Dell V3450 no power from adapter, Battery ok.

Seems in the diagram there is a diode on that line. Check to make sure its not faulty

[nazrul145]

Re: Dell V3450 no power from adapter, Battery ok.

it seems good. also replaced it.

[BCConnectionLLC]

Re: Dell V3450 no power from adapter, Battery ok.

Do you have continuity to the diode?

Only other thing on the line is the pull up resistor

[nazrul145]

Re: Dell V3450 no power from adapter, Battery ok.

diode is ok, and this resistor place is blank.

[BCConnectionLLC]

Re: Dell V3450 no power from adapter, Battery ok.

So going from pin 13 of PU1 to the first pin of the diode is there continuity?

[Djosla]

Re: Dell V3450 no power from adapter, Battery ok.

Few things to check:
-check voltage dividers (pr25,pr12,pr11) on pins 2 and 22 of pu1,AC in shoud be low on order to have voltage on ACOK
-check current sensing resistors pr10 and pr16,short may block ACOK
-check pq2 transistor and pr17 and pr18 an ACOK line

[nazrul145]

Re: Dell V3450 no power from adapter, Battery ok.

Yes there is continuity and this is 3.1v but another side of diode is 0v. and this side continuity to ground 65ohm.

[whaldsz]

Re: Dell V3450 no power from adapter, Battery ok.

Yes there is continuity and this is 3.1v but another side of diode is 0v. and this side continuity to ground 65ohm.

Looks like your SIO needs to be changed. lift one side of D4, and check the continuity of pin 21 to ground if it has 65 ohms.

[nazrul145]

Re: Dell V3450 no power from adapter, Battery ok.

whaldsz you are right, D4 one side also 65 ohms, But i replaced SIO also same. I have replace two sio and also same. When I removed SIO, there is no continuity D3 one side to gnd.