Re: No power on G512LI
Thanks! I might as well try that. I'm not sure how to find the buck converter for the CPU core supply. Can you tell me where it is on the schematic or what the abbreviation is?
vrasp
Senior Member
Last Activity: 07-11-2023, 08:28 AM
Joined: 11-16-2019
Location: Toronto
-
Re: No power on G512LI
I tried this. First, I noticed that at 1 V, the amp draw is 0.87 A. My understanding is that it's not fully shorted to ground or it would draw up to the limit I set on my bench PSU which was set to 2 A. I found that U0301 was getting warm (>30 C). This is the Intel Cometlake-H processor. Same with all the capacitors on the other side of the board where U0301 is. Is this normal?
In case this helps, the resistance to ground on the AC_BAT_SYS line is 2.6 Ohms.Leave a comment:
-
Re: No power on G512LI
I also visually checked the rest of the AC_BAT_SYS line and didn't see anything odd. There are so many capacitors and resistors connected to this line... Is this the kind of scenario where I would inject 1 V then 2 V and so on and check what gets hot?Leave a comment:
-
Re: No power on G512LI
Hey,
I've been trying to figure it out by myself but got stuck.
I replaced the two MOSFETs as well as PR8904, PR8905, PC8905, PR9024, and PD9002. I was still getting about 1.7 V at ACDET (with battery IC removed) I proceeded to desolder pin 2 of PD9002 to isolate the circuit from AC_BAT_SYS and got a nice 3.2 V at ACDET (the 20KOhm from the voltage divider was replaced with 24.3 KOhm so that makes sense). It appears the issues is coming from the AC_BAT_SYS line.
There is continuity with ground on the AC_BAT_SYS line....Leave a comment:
-
Re: No power on G512LI
Super helpful! I m placing an order for everything on that line. Thanks!Leave a comment:
-
Re: No power on G512LI
Sounds good.
I can't find the same MOSFETs (PKCH2BB and QM3058M6AC) in online stores. When I filter out the results for similar MOSFETs with low Rds < 1 milliOhm (PKCH2BB) and < 30 milliOhm (QM3058M6AC) and a Vds limit of > 30 V, nothing with the same package/case shows up. Can I get something from a different package or will it not fit?
Also, do you have any advice/tips on how not to lose resistors/capacitors or other small components when you desolder them? I keep a white piece of paper next to me and place them on there...Last edited by vrasp; 05-26-2023, 12:34 PM.Leave a comment:
-
Re: No power on G512LI
What about the PD9002 diode and the PC8905 capacitor? I m curious to know why they aren't considered as potential culprits.Leave a comment:
-
Re: No power on G512LI
I removed the IC and checked the voltage. It's still 1.69 V at the divider. I'm gonna place the order you mentioned.
What else could be lowering the voltage on that line? It is worth removing the capacitor and checking the voltage again?
Thanks for the help!Last edited by vrasp; 05-24-2023, 04:00 PM.Leave a comment:
-
Re: No power on G512LI
I fluxed and carefully removed, measured, and resoldered PR8904, PR8905, and PR9024.
They all match the resistance values on the schematic.Leave a comment:
-
Re: No power on G512LI
On PD9002 I got
Pin 1: 1.09 V
Pin 2: 0 V
Pin 3: 0.6 V
PR9024 resistance to ground
Pin 1: 78 KiloOhms
Pin 2: 91 KiloOhms
PR9024 voltage
Pin 1: 20.2 V
Pin 2: 0.6 VLast edited by vrasp; 05-21-2023, 12:10 PM.Leave a comment:
-
Re: No power on G512LI
I got
20.2 V on pin 1 of PR8904
1.69 V on pin 2 of PR8904
Resistance to ground at the common junction of PR8904 & PR8905 is 18.8 KilohmsLeave a comment:
-
Re: No power on G512LI
I got 75.5 Kilohms for r1 and 18.8 Kilohms for r2. Based on the calculator, that should give me about 4 V. Does that mean the charger IC is shot?Leave a comment:
-
Re: No power on G512LI
My bad the writings in the schematic were shifted and so were my readings. It goes:
REGN -> 5.95 V
ACDRV -> 0 V
ACDET -> 1.69 V
ACOK -> 0 V
CMSRC -> 0 V
ACP -> 0 V
ACN -> 0 VLeave a comment:
-
Re: No power on G512LI
I finally got around to it. With the charger and battery plugged in I got:
REGN -> 5.95 V
ACDRV -> 0 V
ACDET -> 0 V
ACOK -> 1.69 V
CMSRC -> 0 V
ACP -> 0 V
ACN -> 0 V
Thanks!Leave a comment:
-
Re: No power on G512LI
I m getting "infinite" resistance between all of them....Leave a comment:
-
Re: No power on G512LI
Here are the front and back pictures of the DC jack and battery connectors. I put green dots where I think the MOSFETs are for the DC_JACK. Is that correct?...Leave a comment:
-
No power on G512LI
Hi,
I received an asus laptop G512LI that doesn't power on. Apparently it suddenly turned off. There was no spill or anything like that.
I have some/little experience fixing boards. I have not been able to find a schematic and boardview for this board. Are there other motherboards that are similar for which there are available?
So far I've determined that the adapter is providing 20.2V at J6001 and there is 0.12V on pins 6-8 and 0v on pins 4-5 of PJ6001 (the battery). The badcaps guide says to "check the voltage after the 2nd DC-in MOSFET and... -
Re: Issues in PWM circuit with LC filter to drive Peltier
Thank you! You saved me a ton of time. I removed the diodes and was able to run my cooling ramp.
I am running into another issue, although a minor one. I'd like for the temperature to decrease at a constant rate. It is constant enough when I use one Peltier. However, with two, I get a rapid decrease of a few degrees as soon as the buck converter receives enough voltage to turn on the 2nd Peltier. So the cooling ramp starts at a constant rate, then a sudden drop of a few degrees, then a constant rate again. ...Leave a comment:
-
Re: Issues in PWM circuit with LC filter to drive Peltier
Thanks eccerr0r!
I thought the flyback diodes were to allow voltage spike from the inductor to have somewhere to go when I cut the supply. Can you explain how am I using them wrong?Leave a comment:
-
Issues in PWM circuit with LC filter to drive Peltier
Hi,
I've been trying to build a Peltier circuit that I can control with arduino and create cooling ramps. I've never built a circuit before and only have a basic knowledge of electronics.
I've been researching how to do this and attempted to build it. My circuit is basically a PWM signal sent to a motor driver with an LC filter to smoothen the signal. Since very low temperatures are required, I added another Peltier on top of the first one. The top Peltier needs to be driven at a lower voltage to limit the amount of heat produced and effectively lower the temperature....Last edited by vrasp; 10-27-2022, 08:20 PM.
No activity results to display
Leave a comment: