Re: Inspiron 3421 - No power unless...
Yes, fresh battery.
RTC_RST# and SRTC_RST# are both at 3.18V.
PinGuy
Senior Member
Last Activity: 01-09-2024, 05:59 PM
Joined: 10-13-2016
Location: Buenos Aires
-
Re: Inspiron 3421 - No power unless...
Measured D6001 as described and it is OK.Leave a comment:
-
Inspiron 3421 - No power unless...
It doesn't turn on, but after removing the BIOS battery a few seconds, reinserting it and plugging the charger, it comes on and boots perfectly. When turned off (via "Turn off" option because power button doesn't register, but the switch itself works), it can't be turned on again unless the procedure is repeated. Any clues? -
Re: Dell E7440 turns on for 10-15 seconds then turns off
It was the original issue and it would not start even after changing the CMOS battery. Like as if the BIOS "forgot" its stuff when the CMOS battery died. I reflashed the BIOS and then it started to boot properly.
But then it died again after not using it for a while, and the CMOS battery is fine at 3V this time. I believe it should start even without the CMOS battery, just taking longer to boot, but this one doesn't and the LED pattern is always the same, with or without the CMOS battery.
The charger...Last edited by piernov; 04-07-2023, 02:35 AM.Leave a comment:
-
Re: Dell E7440 turns on for 10-15 seconds then turns off
None of the coils show a short to ground.
The DC mosfets are switching CHAGER_SRC at 13.5v. ACOK is 3.3v so I believe that section is fine.Leave a comment:
-
Re: Dell E7440 turns on for 10-15 seconds then turns off
PR9 measures fine, and I see the PSID pulses coming from PL3 at pin 4 of PU111 as well.Leave a comment:
-
Re: Dell E7440 turns on for 10-15 seconds then turns off
The reading is 1.082v, and reversing the leads is OLLeave a comment:
-
Re: Dell E7440 turns on for 10-15 seconds then turns off
The AC adapter is the original 19.5V @ 4.62A, it measures 19.7V and voltage doesn't drop when turned on in those 10 seconds the power light is on.
I tried this adapter in a working Dell which uses a 3.34A adapter and it works fine.
I tried the adapter from that another Dell on this non-working one and the issue is the same.
In PL3 I only see a small pulse when plugging the charger, and another small pulse after the 10~15 secs when the charge light turns on, right before the laptop turns off.Leave a comment:
-
Dell E7440 turns on for 10-15 seconds then turns off
I got this machine and it would do as described in the title (which from what I saw is a classic for this model). BIOS battery was 2.3V. I replaced it, and it kept doing the same. Also tried with no battery, and same thing. So I grabbed the BIOS files from this post:
[url]https://www.badcaps.net/forum/showpost.php?p=1158027&postcount=69[/url]
After burning both BIOSes, the machine started and worked perfectly on the first try. Then I left it unused in a cabinet for about 2 months, now when I was going to use it the same thing happened
I checked the battery and... -
Re: VR_ON, ICH_POK missing
I found R823 after tracing visually and confirmed RTCVCC is at 3V.Leave a comment:
-
Re: VR_ON, ICH_POK missing
Indeed, +3 and +5VALWP go to 0V after 2 seconds of pressing power.
The first thing I did when checking this one was replacing the old ML1220 battery (was at 1.8V) with a new CR2032, and removed PD104 to isolate the recharging circuit from the battery. CHGRTC is at 3.2V, RTCBATT is 3V.
Could it be that the EC it needs it to be 3.2V to power on?
Will try to check RTCVCC if I find it, as there is no silkscreen for the capacitors and resistors, and there's no board view. Thanks for the pointers!Leave a comment:
-
Re: VR_ON, ICH_POK missing
9, 16, 37, 67 and BIOS VCC are 3V and go to 0V 2 seconds after power button is pressed. So for some reason +3VALW goes to 0 after powering on.
117 is at 0V and blinks to 3V for half a second when power is pressed.
127 is always at 3V (using the AC adapter)Leave a comment:
-
Re: VR_ON, ICH_POK missing
I tried clipping the collector of Q37 to ground but it will not even try to power up this way, not even a brief blink at the power led. I also tried clipping it right when pressing the power button, but the power led goes off right when I send SUSP to ground
...
Leave a comment:
-
Re: VR_ON, ICH_POK missing
Please correct me if I'm wrong, so when there is power but the system is off, SUSP is 1, and all the mosfets it controls are off, and when the power button is pressed, the EC sends a 1 through SUSP#, making SUSP 0 and hence making all the mosfets turn on so the computer starts? Is this how this works or am I getting it the other way round?Leave a comment:
-
Re: VR_ON, ICH_POK missing
Good info, techtiger, thank you.
3VALW is present, but when checking the mosfet that turns 3VALW into 3VS, I found that the SUSP signal is always at 3V, and it won't "flicker" to 0 when powering on, like #SUSP does (to 3V of course), when it arrives to Q37. So what can force SUSP to be always 3V? Maybe a short somewhere? I checked all coil outputs and there are no shorts to ground
Leave a comment:
-
VR_ON, ICH_POK missing
Trying to get a Lenovo G450 to turn on. When pressing power, the power led goes on for about a second, then off. And it won't turn on anymore until power-cycled.
Measuring at the EC (page 36 at the schem), all these signals are at 0V, and blink to 3V for a brief moment when powering on:
SLP_S3, S4 & S5
SUSP#
EC_RSMRST
SYSON
EC_LID
EC_ON
VR_ON is always 0V
ICH_POK_EC is always 0V
What condition is needed for those 2 signals to go high?... -
Re: Samsung NP300E5C turns on once, then won't turn on again
I just checked again after a rest of more than 12 hours and it didn't start. VR_ON goes from 0 to 3.04V after the 10 second delay for bios init (which didn't finish yet as it didn't power on properly), and 2 seconds before the fan would start at full speed.Leave a comment:
-
Re: Samsung NP300E5C turns on once, then won't turn on again
Ok, reflashed orig bios just in case and it is in the same condition. I measured all the coils and get 5.1, 3.3, 1.08. The 3 big ones near the processor measure 0V, and the big resistors near the RAM sockets one is at 1.8 and the other one at 0.9. The one on the other side is the 1.5V, also present. So as it seems, the only thing not being powered on is the CPU, maybe some sort of protection is tripping? Will leave it there more time to check again if it powers up again
Last edited by PinGuy; 12-10-2021, 12:39 PM.Leave a comment:
-
Re: Samsung NP300E5C turns on once, then won't turn on again
After leaving it alone overnight it did not power on, not sure if it is the new bios, or that the failure went permanent... Will keep looking and maybe I go back to orig bios to confirm. If it starts at some point, I will check all coils to try spot the differences.Leave a comment:
-
Re: Samsung NP300E5C turns on once, then won't turn on again
Ok, I burnt the BIOS (thanks for it!) and upon restart, didn't start again and vcore went to 0, so it was not a BIOS issue
The sequence now is: it powers on, but the power LED remains off, about 10 secs later the power LED goes on, and the fan starts full speed. I guess as the vcore stays at 0, it is not making the post-update init. I will leave it resting there for some hours and check again.Leave a comment:
No activity results to display
Leave a comment: