-
-
Re: LA-C421P BQ24780S no ACDRV
Just trawling my old laptop diagnosing posts and seen added posts since original board view request..i lost interest in the board after a couple of months of unsuccessful attempts.
one day i may dig out the L560 board and try the sw 1 top pins bridge only suggestion by rbvdon..
board won't be worth much even if fixed, but hey, sometimes its about the challenge.
smd Flea, thanks for comment regarding mosfet bypass, At the time I watching to many early you tube videos (Sorin) showing mosfet bridging as a solution.
I now understand the dangers of inducing a false start scenario.Comment
-
hello when tape ws1 laptop power on not data heat u401 3v 5v ic
Comment
-
Lenovo YOGA Slim 6 14IRH8 - blowing 4 mosfets every time i plug type-c charger in, why?
ive changed out the, BQ25720, TPS65994BF, ALL the mosfets around the battery connector (with exact same versions), and there are NO shorts that i can find, and nothing gets hot (just mildly warm , like 38C)...
Where else on this board should i check ? Cant be replacing a load of mosfets on each charger plug-in...... any pointers welcome ...
Mosfets inside RED square keep blowing when USB-C Charger is connected (any USB-C laptop charger)...
Blue square items,... -
Hello,
I’m troubleshooting this DG525 motherboard, which is not generating the main power rail. I have checked the first two MOSFETs, measured the resistors and capacitors, and tested all the pins on the BQ24780S.
I replaced the BQ24780S, but the symptom remains exactly the same.
I have no voltage on ACOK, CMSRC, ACDRV, SDA, or SCL. The only voltage present is ACDET at 2.8 V.
The input and output MOSFETs have been tested and are good, and I have also replaced them, but the problem persists.... -
Yesterday, 06:19 PM
Hi everyone, I have this problem that I can't figure out. The Asus X580GD motherboard, with the charger connected, gets 19V to the first MOSFET, but it doesn't go beyond that. Analyzing the schematic, it's powered by the BQ24780S power IC. There are no shorts, the input MOSFETs are working. I even tested them after desoldering and replacing them. I've performed various measurements on the power IC, but ACDRV doesn't go to 25V.
Pin 5 ACOK 6V
Pin 6 ACDET 2.59V
Pin 28 18.8V
ACDRV resistor 4K I removed the R8934 resistor to see if it would return... -
Hi, I'll start by saying that I'm not an expert and I've reached a point where I don't know what to try/do anymore...
Starting from the beginning: I opened this subwoofer for the first time with a very strong smell of burnt electrical components, I realize that on the amplifier board there is a hole between V+ OUT and GND about the size of a finger, the damaged components were the shorted mosfets, two damaged zener diodes and two capacitors. I bought everything, I fixed the hole by cutting the pcb and putting a piece of a perforated board.
I had no problems connecting mosfets and capacitors,...08-27-2024, 12:46 PM -
Hi,
Finally got time to fix this board up.
At first it didn't give any POST codes. Turns out it was an unsupported Celeron D cpu. After dropping in an Celery 2.6gHz the CPU came out of reset with clock signal, but still no post codes. For a while it did work when I applied pressure to the ADP3168 chip, but on next reboot the MOSFETs started to burn. Then I left it as is for months.
Now I came back prepared. Replaced the bad MOSFETs and the ADPxx18k drivers. Now I don't get any MOSFETs blowing up issues anymore. But sadly, the Vcore is missing. The whole VRM isn't...
Comment