help needed on this unit. it freeze when charger is being inserted. but with just the main battery only it works normal. with charger inserted at bootup it will end up in BSOD. i tried already flashing the bios... thanks
Asus FX86F freeze with Charger
Collapse
X
-
Re: Asus FX86F freeze with Charger
Check the usual 2 x DCin mosfets that follow the DCin power adapter connector.
If you have schematics for this unit, link or post them here.
If not (have not checked my database of schematics), locate the DCin connector and search for the usual 8 pin (small black square looking package) mosfets.
Post clear pictures here for a review. You can check the status of these mosfets by removing all power (NO BATTERY either) and check the resistance across the mosfet pins.
source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)
Post each measurement and also the scale used on your meter. -
Re: Asus FX86F freeze with Charger
The MDU and AO parts are N-channel (single) and appear to be fine for replacements.
So far, unable to locate the datasheet for the 4511NH mosfet. Your logic board is 100% identical that uses the AO ?
Check the voltage on each pin of each mosfet:
source (1-2-3)
gate (4)
drain (5-6-7-8)
with the adapter connected. Being N-channel, the gate voltage is expected to be ~25v to enable the respective mosfet.
Update - forgot to ask - what is the charger IC on this logic board? It should be nearby. Perhaps the TI ('BQ') series ??Last edited by mon2; 10-12-2022, 12:18 PM.Comment
-
-
Re: Asus FX86F freeze with Charger
The MDU and AO parts are N-channel (single) and appear to be fine for replacements.
So far, unable to locate the datasheet for the 4511NH mosfet. Your logic board is 100% identical that uses the AO ?
Check the voltage on each pin of each mosfet:
source (1-2-3)
gate (4)
drain (5-6-7-8)
with the adapter connected. Being N-channel, the gate voltage is expected to be ~25v to enable the respective mosfet.
Update - forgot to ask - what is the charger IC on this logic board? It should be nearby. Perhaps the TI ('BQ') series ??
source - 19.85v
gate - 24.92v
drain - 19.85v
@mdu1511:
source - 19.84v
gate - 24.93v
drain - 19.84v
it uses BQ24780s as charging IC.Comment
-
Re: Asus FX86F freeze with Charger
These are good readings. Locate the other mosfets mated with the same charger IC. Need to check the resistance of their pins to be sure they are not defective.
Review the battery mosfet, which may be leaking.
source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)Comment
-
Re: Asus FX86F freeze with Charger
schematics and boardview:
https://www.badcaps.net/forum/showth...hlight=FX505GDComment
-
Re: Asus FX86F freeze with Charger
@Q8800 resistance with respect to ground.
drain - 1.5Mohms
gate - 638Kohms
source - 3.4Mohms
voltages @Q8800:
ON BATTERY:
source - 11.94v
gate - 8.04v
drain - 11.94v
ON CHARGER ALONE:
source - 12.67v
gate - 12.66v
drain - 19.96v
WITH BATTERY and CHARGER connected:
source - 12.92v
gate - 12.62v
drain - 19.72vComment
-
Re: Asus FX86F freeze with Charger
Resistance check, not to ground but across the mosfet pins.
From post #2
check the resistance across the mosfet pins.
source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)
Post each measurement and also the scale used on your meter.Comment
-
Re: Asus FX86F freeze with Charger
sorry for that... i used FLUKE 75 multimeter...
* with mosfet removed from board all resistance reading were infinite...
* with mosfet while onboard:
source-drain = 262Kohms
source-gate = 1.7Mohms
gate-drain = 2MohmsComment
-
Re: Asus FX86F freeze with Charger
With this battery mosfet removed, does the charger continue to power the logic board properly? That is with NO freezing if using only the power adapter?
Removing the battery mosfet will remove the battery as a power source from the equation unless the high side mosfet of the charger is leaking.Comment
-
Re: Asus FX86F freeze with Charger
With battery alone, the battery mosfet Q8800 is removed but the logic board works??
If yes, replace the high side charger mosfet as it must be leaking. Check the resistance like before of the high side mosfet. No battery or adapter during these checks.
With Q8800 removed, the logic board should not be powering up with only the battery.Comment
Related Topics
Collapse
-
by flat-eartherThe charging indicator light on my ASUS X54H laptop is always on even when the charger is disconnected.
Windows also shows ''Plugged in'' when charger is not connected.
This problem started year ago gradually, when unplugging the charger the charging light took several seconds to disappear, then minutes, and now almost always on even when unplugged for an entire day.
Strangely, before sometimes immediately when plugging in the charger the charging light went away, and later came back with it connected.
If I let battery run out and say it has 3% Windows will... -
by NanoTestingI got a 15-IIL05 that failed to turn on BUT IT DID TRY TO TURN ON and then turned off after 30+- seconds, i disassembled it and found a screw loose inside the case.
With charger it turns on, fan spins but gives no image.
Tested main mosfets no short, tested 3.3v,5v,DRAM, CPU etc and they were present.
Reflashed BIOS, same problem.
Replaced both main mosfets.
Checked main mosfets again and i noticed that they closed once the laptop shut down, so i decided to bypass them and used a bench PSU to check how much power the laptop was drawing while trying to turn on, 20v@3A,... -
This specification for the ASUS Chromebook ASUS Chromebook CX1100CNA-GJ0038 11" HD Celeron 4GB 64GB Chromebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the ASUS Chromebook CX1100CNA-GJ0038 11" HD Celeron 4GB 64GB boardview and ASUS Chromebook CX1100CNA-GJ0038 11" HD Celeron 4GB 64GB schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional...09-07-2024, 02:50 AM
-
This specification for the ASUS VivoBook ASUS VivoBook 15 S513 FHD i5 16GB/512GB G3 SSD Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the ASUS VivoBook 15 S513 FHD i5 16GB/512GB G3 SSD boardview and ASUS VivoBook 15 S513 FHD i5 16GB/512GB G3 SSD schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant...09-07-2024, 02:50 AM
-
This specification for the ASUS ASUS E410MA-BV815TS 14.0 HD 1366x768 N4020 4GB 64GB with Office 365 1 Year Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the ASUS E410MA-BV815TS 14.0 HD 1366x768 N4020 4GB 64GB with Office 365 1 Year boardview and ASUS E410MA-BV815TS 14.0 HD 1366x768 N4020 4GB 64GB with Office 365 1 Year schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively...09-07-2024, 02:50 AM
- Loading...
- No more items.
Comment