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Old 08-10-2017, 11:17 PM   #1
mcplslg123
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Default Dell inspiron 3521 la-9104p dead

Model-Dell Inspiron 3521
M/B-La-9104p rev 1.0(A00)
Problem-Dead

The ene kbc was shorted, so i replaced it with a new one and programmed it as well with Rt809F. unit still has no 3.3v

I have tried the following:

01. Replaced another new kbc and programmed-still same
02. Replaced Pu200 with TPS 51125-still same
03.Replaced Pu100(ISL88731)-still same.
04. There is no short on 3v and 5v coils(PL200 & PL201)
05.Tried flashing both Eprom's-still same.

I have noticed one thing which has left me puzzled--If i connect pin16 of Kbd Connector(which is connected to pin 42 of KBC) to Ground-all voltaged appears on the board-3.3v at battery terminals and power switch. Mb wont turn on simply coz connecting pin 42 of kbc to Gnd means KBC is in programming mode.

So whats wrong???
Please advise friends as i have run out of ideas.
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Old 08-12-2017, 01:06 AM   #2
mcplslg123
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Default Re: Dell inspiron 3521 la-9104p dead

No ideas?? or i'm not clear in my explanation of case?
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Old 08-12-2017, 03:44 AM   #3
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Default Re: Dell inspiron 3521 la-9104p dead

Its so difficult to find out .............laptop repair is tough work, sometimes its bother me
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Old 08-12-2017, 08:50 AM   #4
age80
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Default Re: Dell inspiron 3521 la-9104p dead

https://www.youtube.com/watch?v=rifMj6ne920

Check this video you might find it useful and get some more clues...
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Old 08-12-2017, 10:40 AM   #5
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Default Re: Dell inspiron 3521 la-9104p dead

This is schematic and bios dump,
have you a short on 3.3v <-- EC ?
Attached Files
File Type: rar LA-9104P_DELL.rar (4.74 MB, 8513 views)

Last edited by jasko_jacker; 08-12-2017 at 10:42 AM..
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Old 08-14-2017, 12:07 AM   #6
mcplslg123
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Default Re: Dell inspiron 3521 la-9104p dead

Quote:
Originally Posted by jasko_jacker View Post
This is schematic and bios dump,
have you a short on 3.3v <-- EC ?
No short on 3.3v ec
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Old 07-30-2018, 10:56 AM   #7
anandkv123
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Default

thanks
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Old 11-29-2021, 09:12 PM   #8
jimore
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Default Re: Dell inspiron 3521 la-9104p dead

Quote:
Originally Posted by jasko_jacker View Post
This is schematic and bios dump,
have you a short on 3.3v <-- EC ?

thank bios bin tested good
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Old 02-05-2022, 03:34 PM   #9
cowboype
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Default Re: Dell inspiron 3521 la-9104p dead

Quote:
Originally Posted by jasko_jacker View Post
This is schematic and bios dump,
have you a short on 3.3v <-- EC ?
Great. Works fine. Thanks.
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Old 08-12-2017, 10:54 AM   #10
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Default Re: Dell inspiron 3521 la-9104p dead

I remember a similar issue on a thinkpad solved with a pch reflow but in this case you should , In this case you should try to separate 3.3V 5V block from its loads
Attached Images
File Type: jpg Power block.jpg (161.6 KB, 551 views)

Last edited by jasko_jacker; 08-12-2017 at 11:00 AM..
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Old 08-12-2017, 08:58 PM   #11
raajkumar
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Default Re: Dell inspiron 3521 la-9104p dead

Check at PL600 & PL601 for short circuit. And also PU600.
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Old 08-14-2017, 12:07 AM   #12
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Default Re: Dell inspiron 3521 la-9104p dead

Quote:
Originally Posted by raajkumar View Post
Check at PL600 & PL601 for short circuit. And also PU600.
Both the coils are not shorted to Gnd. Checked with a working board. Pu600 is fine
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Old 08-14-2017, 01:14 AM   #13
raajkumar
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Default Re: Dell inspiron 3521 la-9104p dead

i had the same issue on a motherboard. but i don't remember which resistor is damaged. so check resistors around pu200.

Last edited by raajkumar; 08-14-2017 at 01:20 AM..
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Old 08-14-2017, 05:58 AM   #14
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Default Re: Dell inspiron 3521 la-9104p dead

check RE4 and RE1

Last edited by smali; 08-14-2017 at 06:08 AM..
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Old 07-19-2019, 07:15 AM   #15
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Default Re: Dell inspiron 3521 la-9104p dead

dears i have a problem dell 15-3521la-9104p)
it showing the massage battery not identifed system unable to charge
i change battery ,charger
chargig ic
3,5 ic
all starting /charging mosfets
near charging ic components
pch bios 32/io,bios16 bios programmed
io chip kb012qf changed and programmed
but no chance please help me friends
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Old 12-12-2019, 07:56 AM   #16
mcplslg123
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Default Re: Dell inspiron 3521 la-9104p dead

Quote:
Originally Posted by jijunmedia View Post
dears i have a problem dell 15-3521la-9104p)
it showing the massage battery not identifed system unable to charge
i change battery ,charger
chargig ic
3,5 ic
all starting /charging mosfets
near charging ic components
pch bios 32/io,bios16 bios programmed
io chip kb012qf changed and programmed
but no chance please help me friends
This sort of "hit and trial" approach makes things worse and sometimes render the mb unrepairable. Identify the fault first, understand the circuit or seek help in the forum instead of killing mb's.
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Old 07-19-2019, 10:45 PM   #17
mcplslg123
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Default Re: Dell inspiron 3521 la-9104p dead

Can u run the laptop only on charged battery?? Check for shorted caps on battery output lines. What about PS_ID??
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Old 12-12-2019, 01:19 AM   #18
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Default Re: Dell inspiron 3521 la-9104p dead

thanks
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Old 02-06-2020, 12:38 PM   #19
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Default Re: Dell inspiron 3521 la-9104p dead

thanks
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Old 03-19-2020, 01:34 PM   #20
hussaka
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Default Re: Dell inspiron 3521 la-9104p dead

Thank you
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