dell 1545 ac adapter problem

[innocentforeign]

hi every one . I have a Dell Inspiron 1545 and I used to get an error message saying something about using a genuine Dell adapter? my ac adapter type cannot be determined and something about a 65W AC or higher for best operation. Easy way to fix it is by calling dell. i change many charger & battery but same error coming

please help me to solve this problem

[alihomee]

Re: dell 1545 ac adapter problem

you can disable this opption in setup by pressing f2 or you should use the dell 65w orignal adapter.

[rievax_60]

Re: dell 1545 ac adapter problem

hi every one . I have a Dell Inspiron 1545 and I used to get an error message saying something about using a genuine Dell adapter? my ac adapter type cannot be determined and something about a 65W AC or higher for best operation. Easy way to fix it is by calling dell. i change many charger & battery but same error coming

please help me to solve this problem

I had that trouble lately after replacing the keyboard controller IC in a Dell 1545 which was damaged by someone fitting the wrong LCD screen.
The keyboard controller IC communicates with a "1-Wire" IC in the charger via the center pin of the charger's DC plug. The positive power connection is the inner surface of the plug's sleeve.
In the charger there was a protection zenner across the 1-wire IC and a series resistor, I cant remember the exact value, a few hundred ohms I think.

I found that I had solder bridged some pins of the new keyboard controller IC.

[spidey]

Re: dell 1545 ac adapter problem

you can disable this opption in setup by pressing f2 or you should use the dell 65w orignal adapter.

go in to setup and disable the option about charger.

[innocentforeign]

Re: dell 1545 ac adapter problem

thanks all
dear rievax system give error not charging i check the resistor , show value 100k in schematic give 33 ohms i change the resistor check all zenner diode P.Q are good also change keyboard controller IC but same problem coming

[bw4ali]

Re: dell 1545 ac adapter problem

Dear,
kindly change your keyboard ic because its on leg is connected with charger pin.
othervise you must change your MAX ic.other i am here for your help.

[rievax_60]

Re: dell 1545 ac adapter problem

thanks all
dear rievax system give error not charging i check the resistor , show value 100k in schematic give 33 ohms i change the resistor check all zenner diode P.Q are good also change keyboard controller IC but same problem coming

I would have left that resistor alone. Resistors dont change like that.
I remember there was some complicated circuitry along the signal path which included some MOSFETs. I think its protection for the keyboard controller IC incase 19 volts gets applied to the center hole of the DC socket.
There is a place on the small PCB near the DC socket where I see the 1-Wire data on my DSO. There is only one brief burst of data when the charger is first plugged into the laptop.

[rievax_60]

Re: dell 1545 ac adapter problem

thanks all
dear rievax system give error not charging i check the resistor , show value 100k in schematic give 33 ohms i change the resistor check all zenner diode P.Q are good also change keyboard controller IC but same problem coming

I was using this schematic,

Does it show the resistor?

[innocentforeign]

Re: dell 1545 ac adapter problem

yes dear resistor id is (R91) and it is before FET (q6)

connected with keyboard ic (u20b) leg no 63

[rievax_60]

Re: dell 1545 ac adapter problem

yes dear resistor id is (R91) and it is before FET (q6)

connected with keyboard ic (u20b) leg no 63

What value is R91 now?
What total resistance do you measure between pin 63 of the KB IC and the center hole of the DC socket?

[innocentforeign]

Re: dell 1545 ac adapter problem

thanks for support dear first i change used ic but its give same problem . now after change a new u20 keybord ic charger working good and charg the battery thankyou agin for help

[rievax_60]

Re: dell 1545 ac adapter problem

thanks for support dear first i change used ic but its give same problem . now after change a new u20 keybord ic charger working good and charg the battery thankyou agin for help

OK, good.
Although I still think that the purpose of Q6 is to protect the KB IC from spikes, I dont think it gives good protection because the circuit shows a 33 ohm resistor between Drain and Source.
Spiked pins usually measure some low resistance to ground or to supply rail.

[innocentforeign]

Re: dell 1545 ac adapter problem

you are right thanks a lot