Brother, i Have problem with dell 3421 no power issue. Its 5v, 3v ok. I have flashed bios. but no power. SIO power 3.3v and VCC POR 3.3v ok. But Sio not release Rsm_RST. So dont know whats wrong. can any body point out this problem.
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Last edited by nazrul145; 11-01-2014, 07:11 AM. -
Re: Dell 3421, No Power.....
your RSMRST from southbridge that goes to SIO chip so if its missing then do a reflow or change the chip.
typical DELL come on
Just cook it! It's already broken. -
Re: Dell 3421, No Power.....
Thanks, but i already reflow southbridge. is rsmrst# goes to sio to southbridge? or southbridge to sio chip.Comment
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Re: Dell 3421, No Power.....
sio to southbridge
Check SIOComment
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Re: Dell 3421, No Power.....
Do you have all the conditions prior to RSMRST met?Attached FilesComment
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Re: Dell 3421, No Power.....
Thanks everybody speacially Khaahk. I have noticed that 5v_s5 and 3.3v_s5 is not present in U3601 AND U3602. But I have a same working Motherboard this board also 5v_s5 n 3d3_s5 is not preset without power button press. But this schematic indicate 5v_s5 and 3.3v_s5 must be ok befor rsm_rst#. I dont know what happend.Comment
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Re: Dell 3421, No Power.....
Both powered from adapter?Comment
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Re: Dell 3421, No Power.....
No, i used bench power supply. Both from power supply, also use adapter. The ok motherboard RSMRST# is ok but faulty motherboard rsmrst not present.Comment
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Re: Dell 3421, No Power.....
It beeps 3x..Comment
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Re: Dell 3421, No Power.....
do a reflow!Just cook it! It's already broken.Comment
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Re: Dell 3421, No Power.....
Hi bro I was googling around to get the schematic of this board, and I finally
could get it on this thread.
So what happens is I got this notebook, and as soon as I plug the dc adapter the PSU light goes off. So there's a short somewhere. some guys form chip level repair told me to go straight to the VCC core section and lift all fets and check them I did that, and fets were fine.
Then I focused myself on the VIN section I lifted all fets and they were fine.
any ideas how I should go on, I'm thinking on 3v 5v always regulator and fets.
But I'm starting to think maybe the SIO could be shorted.
can you give me some ideas. Thanks. I have a lab supply to inject voltage if needed.Comment
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Re: Dell 3421, No Power.....
check power on rst,then scl and sda with cro if not change I/osigpicComment
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Just cook it! It's already broken.Comment
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Re: Dell 3421, No Power.....
turning this old thread live again to know the solution for 3 beeps error.
and also PL4401 is grounded.
Looks like PU4201 is dead, will replace it and let you know but what was the earlier fix.Last edited by dspok; 09-05-2015, 10:57 PM.Comment
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Re: Dell 3421, No Power.....
inject psu to short to see burning componentComment
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Re: Dell 3421, No Power.....
Thanks for update schematicComment
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Re: Dell 3421, No Power.....
My personal experience is PM_PWRBTN# signal is lost and I just reflow the chipset and the laptop can switch on. Thank's for sharing the schematicComment
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Re: Dell 3421, No Power.....
Thx for fileComment
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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
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The screen seems to blackout and stay black, but with a flashlight I can see the display.
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Assuming... -
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This one's a weird one, and still unsolved despite it having gone back to Dell once.
Specs
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Hello!
This is my first post for help, and I am quite newer to board repair, so bear with me.
I have this board here (LA-E671P), with no power, and doesn't charge. No lights come on when plugged in.
After visual inspection of the board, U22 is obviously blown up. This is the for backlight, and there is no shorts present after removing the chip and replacing.
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Comment