Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

red lead on pq41 pins 5,6,7,8 black lead on ground = open
black lead on pq41 pins 5,6,7,8 red lead on ground = .873 ohms

this seems correct if PC10, PC91, PC90, PC9 are working correctly

Yeah that makes sense. With the red lead on ground measuring to BAT-V will give that 0.873 ohms from the body diode in PQ50.


Have you checked the current sense resistors PR155 and PR133 for open circuit? Should also check PR42,42,44,56 for open or high value.

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

OK, I will check that and report back. Could this also be causing the main power not to come on as well? This is board has multiple issues and just trying to trouble shoot and fix one at a time in the hopes of making it work again. The person who took this machine apart was not very skilled at doing so and they are hoping that I can get it to work for them again.

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

I suspect the battery not getting voltage to charge and the LEDs not coming on stem from the same problem, whatever it is. Seems that something is preventing anything from coming up.

I can try to help but don't have specific experience in repairing these. I can think of things in general you can check which might be the problem but that's about it.

Probably one of the other guys here will have a better idea of where to look though.

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

everything looks good that you mentioned.

is there anything to be bypassed to force the charging circuit to come on?

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

I don't think you can force the charger on. But the charger IC will have some conditions which need to be met before it will start charging, the datasheet would explain this.

You may be able to check and see if all these things are satisfied, and if they are not, it may help point in the direction of why.


It might help to look at the standby power supplies and signals from the EC too, though.

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

thank you for the info I will take a look at it and get back to you

[meritosari]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

check voltage pr133 pin 1 & 2
on pu2
2
3
13
27
28

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

check voltages pr133
pin 1 19.22 vdc
pin 2 19.21 vdc

check voltages pu2
pin 2 3.87 vdc
pin 3 3.19 vdc
pin 13 0.00 vdc
pin 27 19.16 vdc
pin 28 18.88 vdc

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

I think ACOK signal (Pin 13) is not correct, since you have ACIN above 3.2v, according to the datasheet, ACOK should be high (+3v)

Check pullup resistor PR59 is not open circuit.

If you don't get voltage on either end of PR59 then +3VPCU rail is probably not working.

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

PR59 has no voltage on either side so I cause that means +3Vpcu is not working or is open so now where do I go and check? possibly pu3 as I think that supplies 3v/5v power to system.

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

Yes PU3 (page 30) is the controller for +3VPCU and also +5VPCU rails.

Do you get any voltage at inductors PL4 and PL3?

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

PL3 and PL4 no voltage
pin 16 PLU3 18.89 vdc

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

Can you list what voltages are on PU3:
Pin 8, Pin 13, Pin 17, Pin 18

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

Pin 8 3.34 vdc
Pin 13 5.23 vdc
Pin 17 5.01 vdc
Pin 18 3.34 vdc

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

It looks like the VREG5 and VREG3 outputs from PU3 are enabled and OK, but while the switching outputs are also enabled (Pin 18/ENC is above 2v) the main outputs are not running.

I think this would imply that PU3 may be bad or there may be a short on +3VPCU or +5VPCU.

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

how could I find a short if there was one? first with just battery connected, and then with just ac adapter connected?
Thanks
Tom

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

No, with battery and power disconnected, measure between PL3 and Ground. Also measure between PL4 and ground. Measure in both directions (swap probes) to be sure.

[tfs2015]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

No short but low resistance Values. Did notice that pc58 and pc46 missing from board.

[Agent24]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

No short but low resistance Values. Did notice that pc58 and pc46 missing from board.

Missing as in removed or never there to begin with? Can you post photos of the pads where they would be?

[fddizon]

Re: Acer Aspire One D270 Netbook has no Power or Battery charge Indicator

TFS2014,

try to locate this ceramic cap. it might be the same faulty part..
see picture attached...

ceramic cap near a coil bottom right red rectangle