Thanks for your help mon2!
I soldered a jumper wire from the capacitor directly to the current sense resistor and plugged in power.
Board powers on just fine now.
Even though this wire is enameled, I'm going to replace it with a wire that has red plastic sheathing just to be sure nothing shorts out over time. Also a red wire will look better with the board.
Announcement
Collapse
No announcement yet.
User Profile
Collapse
-
Last edited by ResoluteHawk; 05-31-2024, 09:24 AM.
-
Does anyone have any other ideas on how I can fix this? Maybe there's something we're missing?
Is it ok if I just run a wire from ACP directly to the current sense ACN? I don't know if it's a good idea for two pins to be soldered to the same connection point.Last edited by ResoluteHawk; 05-15-2024, 11:19 AM.
Leave a comment:
-
PQL8901 measures 0.215V.
ACN voltage is now 7.3V at Pin #2 but still 4.3V at the current sense pin.
This is with just the charger with current sense resistor desoldered.
Something else must be wrong here.
I don't have the wire with me and I'll have to bring it with me tomorrow, but even if I were to solder a wire from ACN on the capacitor and connect it to ACN at the current sensor, wouldn't we still only get 7.3V?Last edited by ResoluteHawk; 05-09-2024, 12:27 PM.
Leave a comment:
-
No battery is connected. This was with just the charger plugged in.
Leave a comment:
-
Ok so there's something I really don't understand about how the input circuit works.
I just desoldered the current sense resistor to see what the trace looked like underneath it and see if it was damaged in any way, but I also figured I'd like to see what happens with the voltages if the CLR isn't there. Plugged in power, and now I'm getting 20V at the ACP side and 26V on the MOSFET gates, but 4.3V at the ACN.
Why does removing the current sense resistor yield these results?
What is the purpose of ACP and ACN and why do I still have 4.3V at ACN with the current...Last edited by ResoluteHawk; 05-09-2024, 11:02 AM.
Leave a comment:
-
Ok that makes sense.
I suppose I could just run a wire from ACN on the capacitor connecting to Pin #1 on the BQ chip directly to the current sensor and see what happens. That's what the trace is doing internally anyway; it would be a dodgy repair but at least the connection would be restored.
Leave a comment:
-
Post #11 doesn't mention anything about what CLR is. I have no idea what he is referring to.
Also, I checked the two diodes that supply the power to the BQ chip, and both of those diodes have a 0.3 voltage drop from one end to the other.
Current sense resistor one end to the other end => Continuous tone.
ACP at BQ chip to the current sense resistor => Continuous tone.
ACN at BQ chip to the current sense resistor => 0.8 voltage drop < something wrong here
Connection between ACN and ACP directly on the BQ chip pins => Above 3M Ohms
...Last edited by ResoluteHawk; 05-09-2024, 08:37 AM.
Leave a comment:
-
-
I'm also going to add that the orange charge light (middle LED) comes on when just the battery is connected and the laptop is powered off.
There should be no charge light since no charger is connected.
I found another [URL="https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/95891-asus-ga401qm-dead-no-lights?p=1766229#post1766229"]post on this forum[/URL] from someone who said they had 4V on the main power rail with just the charging cable plugged in (just like...Last edited by ResoluteHawk; 05-08-2024, 06:40 PM.
Leave a comment:
-
Resistance between pins 1 and 2 of the BQ chip rises north of 3M Ohms. It should be continuous as measured on a working machine.
Might be looking for a blown 0 Ohm resistor somewhere.
Also, new discovery: Laptop turns on and POSTs into the BIOS with just a battery.Last edited by ResoluteHawk; 05-08-2024, 05:01 PM.
Leave a comment:
-
Couldn't have soldered those pins any better.
[ATTACH=JSON]{"data-align":"none","data-size":"medium","data-attachmentid":3267388}[/ATTACH]
Same readings still.Couldn't have soldered those pins any better.
[ATTACH=JSON]{"data-align":"none","data-size":"medium","data-attachmentid":3267388}[/ATTACH]
Same readings still....Last edited by ResoluteHawk; 05-08-2024, 04:03 PM.
Leave a comment:
-
Also, I should have mentioned that after I restored the 5V rail to normal resistance, I also had to take PC9301 off the board as it was a blown capacitor dragging the battery charge rail down to ground. Resistance after removing that cap is back to normal.
I'm wondering if the cause of this no power issue is somewhere in the protection circuit.
Leave a comment:
-
Pins on the BQ chip are soldered perfectly, and the pins make contact with the board. Same resistance to ground is present on both sides of PRS8901, but not on the BQ chip. BQ chip presently on the board is confirmed working correctly on another board.
Leave a comment:
-
Just tried replacing it with the exact same mosfet from a working board. Same result. Still 4V at the current sense resistor, 20V at the drain of the first mosfet, and 0V at the source.
Leave a comment:
-
ASUS GA401QM No ACDRV, No CMSRC
I have an Asus G14 (GA401QM) that has a power issue. Originally the board had a shorted 5V rail and dead EC. I reballed a working EC, soldered it on, and I resolved the 5V issue by replacing the APL6012 and the low side 5V mosfet. Resistances on all power rails are healthy now, but 20V does not make it through the first MOSFET. 20V is present on the drain of the first MOSFET, but there is no voltage on the gate or source.
When diagnosing this issue, I thought that the issue was due to the BQ24800 chip not outputting the correct signals so I soldered on a known working chip and the...
-
I don't think reprogramming the BIOS chips is going to do very much since it POSTed just fine. Your BIOS chip is the one in the 3rd image (the WinBond chip below the VENDOR: TRIPOD text).
Proceed at your own risk however. Did you try reseating the memory at all? What about swapping the memory?
Leave a comment:
-
Re: Vostro 3510 LA-L246p missing 3.3V and 5V
Do you get a charging light?
Disconnect all power. Check the resistance to ground on the 3.3V coil, the 5v coil, 1.8v coil, and Pin #8 of the BIOS chip.
Also, check resistance to ground at the input current sense resistor.Last edited by ResoluteHawk; 10-02-2023, 12:02 PM.
Leave a comment:
-
Re: Dell Inspiron 3520 PW Removal
Please disregard. I figured it out using information from Post #48 in this thread: [url]https://www.badcaps.net/forum/showthread.php?t=87872&page=3[/url]Re: Dell Inspiron 3520 PW Removal<br...2&page=3[/url]
Leave a comment:
-
Dell Inspiron 3520 PW Removal
I need to have a password removed from a Dell Inspiron 3520.
I'd also like to know how this process is done because I cannot find any information on where the BIOS password header starts and ends, and I'd like to be able to remove the BIOS password without completely erasing the IC and rewriting it.
Thanks....
-
Re: ASUS g731 fan control not working
Typically, if an EC/SIO chip is BGA, it will receive its programming from the BIOS chip.
Just make sure that you order a blank chip.
Leave a comment:
No activity results to display
Show More
Leave a comment: