*SOLVED !!!* AAone doesn't power on:lights flash and dim out

Re: AAone doesn't power on:lights flash and dim out

Ok, jerryt, I've scanned the Charger module page with my voltages.Please see below and let's see what you get.

 

Re: AAone doesn't power on:lights flash and dim out

OK X33, hopefully I can locate all these test points on the motherboard.

Seems pretty straight forward.

 

Re: AAone doesn't power on:lights flash and dim out

It is pretty straight forward. I don't recall locating test points per se, but measured on the component's pin.

 

Re: AAone doesn't power on:lights flash and dim out

@ X33 Most likely these numbers will help you troubleshoot your board, but they would not appear to pertain to the problem board I have.

Tested only the problem motherboard, but it does have a working charging circuit.
AC and Battery connected.
All values are in Volts DC.
Note! voltage increased during testing as the battery charged

DC in = 19.6

5 battery connections on motherboard looking down
/ 12.5 / 0.2 / 2.5 / 2.5 / 0 /

PU1
Pin 2 = 4.0
Pin 13 = 3.2 (DC)
Pin 22 = 18.8
Pin 26 = 5.0

PQ2
Pins 1, 2, & 3 = 19.7
Pin 4 = 8.9
Pins 5, 6, 7, & 8 = 19.7

PQ3
Pins 1, 2, & 3 = 19.8
Pin 4 = 19.2
Pins 5, 6, 7, & 8 = 12.5

PQ6
Pins 1 & 2 = 19.6
Pin 3 = 1.0
Pins 5, 6, & 7 = 7.8
Pin 8 = 6.0

PQ20
Pin 1 = 20.0
Pins 2 & 3 = 19.1
Pins 4 & 5 = 0
Pin 6 = 9.0

PQ21
Pin 1 = 19.0
Pin 2 = 0
Pin 3 =0

Maybe you could come up with some checks for the problem motherboard I have? Thanks

 

Re: AAone doesn't power on:lights flash and dim out

Interesting readings there, jerryt.

One correction, (must be a typo): PQ20 doesn't have a pin9. I am sure you meant pin6.

Which test points (voltages) are you interested in, so I can check on my board?

Oh and by the way, have you read about the ziplock-bag-in-the-freezer trick?

 

Re: AAone doesn't power on:lights flash and dim out

Yes, that is a typo.

Test points for a motherboard which shuts off, as soon as the LCD screen gets power during post. Problem persists with LCD disconnected. If you could identify the test points on the schematics for me. You appear to be able to understand the schematics well and I could use your help, Thanks.

I had experienced this trick with a 6 month old AOA150, but the problem would keep returning. Finally had Acer change the motherboard under warranty.

 

Re: AAone doesn't power on:lights flash and dim out

Yeah, that's what I thought about the freezer trick= temporary fix, since the sensor is built-in into the processor(according to schematics/datasheets)...

I've looked at the schematics for the lcd on/off circuit, but what throws me off is the fact that different models have different adaptations of this circuit.

Anyway, I'll look on my board to see what I can gather for you.

Thank you for taking the time to get those readings for me, jerryt!

I'll get back with my findings.

 

Re: AAone doesn't power on:lights flash and dim out

jerryt, I am sorry but I was away this weekend and I didn't have a chance to work on the lappie. I hope I'll get back with some results after Thursday.

 

Re: AAone doesn't power on:lights flash and dim out

Hey all. I was the person in the original thread you linked to x33. Its interesting to follow what you guys are finding out, even if its way beyond me. The original laptop I had problems with eventually just became spare parts, but I've actually come across another AAO with the same problem, so for now its just sitting arond doing nothing. But if you guys figure something out maybe I can breathe life into it again!

 

Re: AAone doesn't power on:lights flash and dim out

Hi Chef Borjan and welcome back to check out this issue. Your post was the only one describing the issue I was having and then, jerryt "joined" the club with another similar problem.

I have to admit that you disappointed me when you shorted out your board , therefore killing any early chance of detecting the culprit :lol:

I am very inclined to replace two of the circuits in the charging module which, at this point, I think they must be the culprits.

Anyway, I'll keep posting my findings and hopefully with everybody else's help, we will be able to find the cure for this kind of problems.

jerryt, just a suggestion for you until I'll be able to check the voltages on my board: have a look at page 17 on the m/b schematics. I think that's where your faulty component is (LCD power switch section), either Q26 or Q22.

 

Re: AAone doesn't power on:lights flash and dim out

I see two clues in this troubled motherboard.
1) Shuts down when LCD powers up - Maybe LCD circuit?
2) Trouble getting motherboard to enter Macles Bios Recovery (takes ten attempts to get Flashing Power Switch), but when in Bios Recovery - Computer never commpletes the Bios Recovery, Power Switch Flashes indefinately (I let it go overnight once). I believe that the Bios Recovery checks that the computer has both AC and Battery connected or it will not write the bios.

So either I have a corupt bios, or
Some 5v or 3 volt source never switches on during pre post

The shutdown reminds me of a time I had shorted the USB power on a different machine and so as soon as the machine would power the usb it shut off the whole machine. So if it was a suspected short I would need to start isolating which circuit, certainly a circuit which is not powered up during the Bios Recovery.

I might be willing to try and change the Bios chip if someone thought it was a good attempt at a solution.

 

Re: AAone doesn't power on:lights flash and dim out

Jerryt, I don't think it has anything to do with the BIOS chip. It seems like a faulty component, and one of the controllers just goes into protection mode to avoid further damage. Probably that's exactly why the BIOS recovery doesn't work: POST sequence tells the controller/BIOS something is wrong, and I guess it just hangs in that state. I personally wouldn't force the recovery procedure until I'd figure out the video/LCD issue.

Sorry I can't be of more help these days, but I'm overwhelmed at work and can't even hope to get close to my sick AAO :cry:

 

Re: AAone doesn't power on:lights flash and dim out

@ X33 would you recommend unsoldering and lifting a leg on either Q26 or Q22?

 

Re: AAone doesn't power on:lights flash and dim out

jerryt, I wouldn't do that, as you'd modify the voltages applied and may damage something else down the road... I'd suggest removing the "turn ON signal" which is applied to the base of Q24, which is a simple digital transistor that acts as a switch for the rest of the circuit. That signal comes directly from the North Bridge (Intel 945), but unfortunately there's no mention of its normal state low or high. My logic tells me it should be LOW, while HIGH would tell Q24 to turn on the LCD. If by any chance, Quanta designed it the other way, then a HIGH signal would keep the LCD off, while a LOW signal would turn it on.

Here's the datasheet: http://www.nxp.com/acrobat_download/dat ... RIES_6.pdf

I think is better to get the readings off the base of Q24 before you desolder its base, to get the logic of the signal. It will avoid drawing the wrong conclusion.

That's how I'd proceed.

I am pretty sure LOW= 0V and HIGH=5V

Let me know the outcome!

 

Re: AAone doesn't power on:lights flash and dim out

Well, jerryt?? Any news, any progress??

 

Re: AAone doesn't power on:lights flash and dim out

No time for this hobby at the moment...

 

Re: AAone doesn't power on:lights flash and dim out

Measure the three legs on Q24 and Q26 with battery and AC adapter attached.

There was no voltage changes on any legs when I turn on the motherboard. Both transistors had the same readings
Pin 1 = 0 volts
Pin 2 = 3.0vdc
Pin 3 = 0 volts

@X33 How have you made out with your motherboard?

I got another problem motherboard, where the Winbond WPCE775LA0DG gets real hot as soon as any power is applied to the board. The person I got this second board from had shorted CN11 to a trace going to WPCE775LA0DG, so bottom line I have a board full of spare parts.

 

Re: AAone doesn't power on:lights flash and dim out

Well, I've actually had quite some time on my hands this weekend and tomorrow too(since it's a civic holiday here in Canada). I've checked my m/b and rechecked it and still something is fishy. I have a feeling PU1 and/or PQ6 are busted, therefore I'll order them both and replace them.

Are you sure??? Q26 should have 19v on pin3 (Vin). If this is true, then you must have found the problem. Let me know and we'll take it fom there..

Anyway, pin2 on Q24 should see a different voltage when you turn on the power, as I said previously. It receives a high/low signal (0v or 5v) straight from the north bridge.

I think you're getting closer...

Regarding the other board, is good to have some extra parts on your hands- the sad part is that you don't know if the parts are reliable (and can't tell which ones either).

 

Re: AAone doesn't power on:lights flash and dim out

Yes, I am sure

Measure the three legs on Q24 and Q26 with battery and AC adapter attached.

There was no voltage changes on any legs when I turn on the motherboard. Both transistors had the same readings
Pin 1 = 0 volts
Pin 2 = 3.0vdc
Pin 3 = 0 volts

LCD is not trying to come on anymore.

 

Re: AAone doesn't power on:lights flash and dim out

jerryt, follow the trace of Vin to see where is getting interrupted. You SHOULD have 19V on it.

Check it first on PQ2 pins 5-6-7-8, that's where it starts.

Have you shorted anything while getting the other readings??