ACN to ACP is continuous. Main power rail is not shorted
PQ1001
Drain to Source => 2.7M Ohms
Gate to Source => 435K Ohms
Gate to Drain => 2.3M Ohms
PQ1002
Drain to Source => 238K Ohms
Gate to Source => 230K Ohms
Gate to Drain => 3K Ohms (This seems really low)
Removed PQ1002 and measured for ACDRV. It's present now.
Can't believe it was that simple. All I have to do is replace this little prick lol.
ResoluteHawk
Senior Member
Last Activity: 04-20-2025, 03:59 PM
Joined: 11-02-2021
Location: Kalamazoo
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Sorry; see my post above. I think I posted that while you were typing your reply. Woops.
Anyway, PR66 is not present on my board. There's empty factory solder pads.
PR1024 measured 433K Ohms before I swapped it with a 320K Ohm resistor to get the 2.6V on ACDET.Leave a comment:
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Swapped out PR1024 with a 320K Ohm resistor and now 2.6V is present on ACDET, but still no charge light and input mosfets are still off.
0.8V is still present at the Source on PQ1001 and PQ1002.Leave a comment:
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Quanta 0P5 (DA0P5HMB8E0-Rev E) Missing ACDRV
I have an HP 15-DY laptop in because the battery is not charging.
If I use a charged battery, the laptop powers on but the battery will not charge, however the orange charge light does turn on. The laptop loses power as soon as I disconnect the battery.
I've replaced the BQ247 chip with a known working one and I get the same issue and the same measurements.
Measurements are as follows:
BQ728 IC
VCC (Pin 20) => 19V
CMSRC (Pin 3) => 0.8V (This is a problem but I can't figure out what's causing the low voltage)
ACDRV (Pin...Last edited by ResoluteHawk; 04-10-2025, 11:46 AM. -
That's just the way that the EC and lid sensor is designed. All G14's that I've worked on do this as long as the screen is open when you plug it in....Leave a comment:
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Check resistance AND voltage for all power rails. You could have a power rail with a lower than normal resistance that is being dragged down by a faulty mosfet that is leaking voltage.
On these G14's, your resistance values on all primary and secondary power rails (19V, 5V, 3.3V, 1.8V) should be in the kOhms with the exception of the memory (1.2V) coil which should be around 100-250 Ohms depending on which brand of RAM you have.
Also if the laptop is restarting every 10-15 seconds, I'd also have a look at the resistance of the CPU VCORE coils. They should be 4-8 Ohms....Last edited by ResoluteHawk; 12-03-2024, 07:40 AM.Leave a comment:
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This is an inductor. It is very likely, if not 100%, to NOT be the cause of the board not powering on.
You need to start by finding the DC-IN mosfets and measuring the drain of the second mosfet to ground in Diode/Continuity mode.
The mosfets that I am referring to look to be above and to the left of the inductor that you circled in the first picture.
If this is a typical Alienware board, it is 99% going to be an issue with the CPU VCORE DRMOSFETS.Leave a comment:
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Your 3V/5V regulator very likely is not bad and is not the cause of your problem. It's not a bad idea to replace it along with the Super IO chip, but the TI1225 is heating up because the output is shorted, thus you're seeing a symptom of what the actual problem is.
Take the ENE Super IO chip off the board and replace it. You'll have to get one that is either already preprogrammed or program it yourself using the firmware on MSI's website and an ENE programmer.
When you're doing board repair/diagnostics, you must know that just because a component is heating up does NOT...Last edited by ResoluteHawk; 12-03-2024, 07:24 AM.Leave a comment:
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Lenovo Legion S7 15ACH6 Not Posting
I have a customer that brought in a Lenovo Legion S7 15ACH6. The problem is that the laptop is not posting.
My first thought was to take out the DRAM and put it back in.
No POST.
Then I swapped the dedicated RAM with good known working RAM.
No change.
I then measured to see if 1.2V was being generated for the memory to turn on, so I measured PL600 which is where the output of the 1.2V rail is.
Resistance was good; measuring ~40Ohms with the slotted RAM in.
I took the slotted memory out and measured again.
Resistance with...Last edited by ResoluteHawk; 12-02-2024, 10:49 AM. -
I put the BIOS that you posted through the disable RAM script and flashed it; I'm still running into the same problem.
If this script is actually doing what it's supposed to be doing, then I'm likely running into a problem with a dead chipset/APU, but this diagnosis doesn't make sense since all voltage rails are present with good resistances.
CPU and GPU are getting slightly warm but nowhere as hot as they should be for system power on, and the system is running for 5+ minutes. CPU and GPU VCORE voltages are present.
I have no other ideas at this point.Last edited by ResoluteHawk; 12-02-2024, 09:20 AM.Leave a comment:
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Thank you! I'll give this a shot on Monday....Leave a comment:
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Lenovo Legion S7 15ACH6
Serial Number: PF31VQ4K
Motherboard Model: BM5070_V1.4
Edit: Found the On Board RAM Disable script; Fingers crossed that this works.
Edit2: Did not work. All voltage rails are present but CPU and GPU do not get hot. No shorts are present and resistances on all rails are good. Using known good slotted RAM and the fans spin with keyboard lights, but no POST.Last edited by ResoluteHawk; 11-30-2024, 02:10 PM.Leave a comment:
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Hi! If possible, I need to disable the onboard RAM as it has issues with the solder joints under one or more of the chips.
My customer is not going to want to pay for reballing the onboard RAM or replacing it, so if there is a way to just disable the onboard memory I'm sure they will be ok with it and they can just buy higher capacity slotted RAM.
Thanks....Leave a comment:
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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.Last edited by ResoluteHawk; 05-31-2024, 09:24 AM.Leave a comment:
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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:
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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:
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No battery is connected. This was with just the charger plugged in.Leave a comment:
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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:
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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:
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