Dell Inspiron 3521 [La-9104p] no power

[classicandy]

Hello, Please I have this Dell Inspiron 3521 [La-9104p] that is dead. There is no visible damaged component. It just tripped off while booting one certain day and has not powered on since then. Doesn't charge either.

I have replaced PU200 [3.3V/5V IC]

Currently, when I connect the charger;

B++ is present

3.3VALWP/5VALWP not present
VREG3 and VREG5 is present
PGOOD is not present

RTC is ok.

Where else do I need to check to determine the fault?

[Techtiger]

Re: Dell inspiron 3521 la-9104p dead

it's better you open a new Thread if you could, for 3/5VALWP you need Enable from SIO voltage on pin 6 20 on PU100 and you need +PWR SRC to PQ100 PQ101 & what is the resistance PL102 PL101 ?

[piernov]

Re: Dell Inspiron 3521 [La-9104p] no power

Moved to a new thread for a different problem. (originally posted in https://www.badcaps.net/forum/showthread.php?t=63872 )

[kiraro]

Re: Dell Inspiron 3521 [La-9104p] no power

What about :

UE1:
-Pin 111, EC_VDD0 (3.3v)
-Pin 110, ACIN
-Pin 112, EC_ON
-Pin 115, LID_SW#

PQ201:
-Pin1 voltage, check PR214(100k), VL(5v) present in one side of this resistance.
-Pin2 voltage(EC_ON through PR213)? and check PR213(2.2k).

[classicandy]

Re: Dell inspiron 3521 la-9104p dead

it's better you open a new Thread if you could, for 3/5VALWP you need Enable from SIO voltage on pin 6 20 on PU100 and you need +PWR SRC to PQ100 PQ101 & what is the resistance PL102 PL101 ?

okay. Thanks.

By +PWR SRC, I guess you mean B+. PQ100 and PQ101 have B+
No PL102. I think you meant PQ102. I can't get any resistance on PQ102 or PL101.

No voltage on Pin 6 and 20 of PU100 [Even on known good board]

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

Moved to a new thread for a different problem. (originally posted in https://www.badcaps.net/forum/showthread.php?t=63872 )

Thanks

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

What about :

UE1:
-Pin 111, EC_VDD0 (3.3v)
-Pin 110, ACIN
-Pin 112, EC_ON
-Pin 115, LID_SW#

PQ201:
-Pin1 voltage, check PR214(100k), VL(5v) present in one side of this resistance.
-Pin2 voltage(EC_ON through PR213)? and check PR213(2.2k).

Thanks. Here are my readings:

UE1:
Pin 111 = 3.36v
Pin 110 = 3.0v
Pin 112 = 3.36v
Pin 115 = 0v

PQ201:
Pin 1 = 0v
Pin 2 = 3.36v

PR214 = 56K ohms
- Pin 1 = 0v
- Pin 2 = 5v

PR213 = 2.1K ohms
- Pin 1 & 2 = 3.36v

[kiraro]

Re: Dell Inspiron 3521 [La-9104p] no power

what voltage you get on ENTRIP1 ( pin1 of pu200) and ENTRIP2 (pin6 of pu200)?

[lapfix]

Re: Dell Inspiron 3521 [La-9104p] no power

Without the voltage on pins 1 and 6 the chip is being told to "turn off "the outputs though.
So measure the voltage on pins : 1.6.13.

What about ps_id pin 16 on UE1

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

what voltage you get on ENTRIP1 ( pin1 of pu200) and ENTRIP2 (pin6 of pu200)?

Pin 1 = 1.36v
Pin 6 = 1.36v

compared with a working board, its similar

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

Without the voltage on pins 1 and 6 the chip is being told to "turn off "the outputs though.
So measure the voltage on pins : 1.6.13.

What about ps_id pin 16 on UE1

Pin 1 = 1.36v
Pin 6 = 1.36v
Pin 13 = 3.6v

PS_ID:
3.3v not present, straight from PJPDC [DC IN] Pin 1 to Pin 16 of UE1.

+5VALW and +3VALW needs to be present for PS_ID to have 3.3v

[lapfix]

Re: Dell Inspiron 3521 [La-9104p] no power

with the PU200 voltages requirements that you got at pins : 1.6.8.13.16.17...and you don't have the outputs at pins :11.20 , a bad chip or a short are still the most likely causes.

With diode mode measure VREG3, VREG5, PL200, and PL201 (that's pins 8, 17, 20, and 11) for shorts to ground.

NB : PS_ID it's not straight from PJPDC [DC IN] Pin 1 to Pin 16 of UE1, what's the voltage at PQ901 (Drain ,source and gate )

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

with the PU200 voltages requirements that you got at pins : 1.6.8.13.16.17...and you don't have the outputs at pins :11.20 , a bad chip or a short are still the most likely causes.

With diode mode measure VREG3, VREG5, PL200, and PL201 (that's pins 8, 17, 20, and 11) for shorts to ground.

NB : PS_ID it's not straight from PJPDC [DC IN] Pin 1 to Pin 16 of UE1, what's the voltage at PQ901 (Drain ,source and gate )

Regarding PS_ID, what i meant was, I checked all the components connected in one way or the other on the PS_ID line, starting from Pin 1 of PJPDC down to Pin 16 of UE1.......

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

with the PU200 voltages requirements that you got at pins : 1.6.8.13.16.17...and you don't have the outputs at pins :11.20 , a bad chip or a short are still the most likely causes.

With diode mode measure VREG3, VREG5, PL200, and PL201 (that's pins 8, 17, 20, and 11) for shorts to ground.

NB : PS_ID it's not straight from PJPDC [DC IN] Pin 1 to Pin 16 of UE1, what's the voltage at PQ901 (Drain ,source and gate )

no shorts to ground on VREG3, VREG5, PL200 and PL201 (PINS 8, 11, 17 & 20)

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

But I noticed that the Charging IC (ISL88731C) gets warm a little. I did the Isopropyl test and compared it with a known good similar motherboard.

I've also compared voltages on the charging IC with charger plugged in (without battery), they seem to have the same readings.

What could be the cause and solution?

[Ikung]

Re: Dell Inspiron 3521 [La-9104p] no power

I've also compared voltages on the charging IC with charger plugged in (without battery), they seem to have the same readings.

Hi, can you measure again all pins on PU100 with battery connected?

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

Hi, can you measure again all pins on PU100 with battery connected?

Here are the new readings with battery connected

[Ikung]

Re: Dell Inspiron 3521 [La-9104p] no power

Here are the new readings with battery connected

ISL88731C does not function when VDDSMB is below its specified Under Voltage Lockout (UVLO) voltage. All of the SMBus registers in ISL88731C are powered by VDDSMB and are set to zero when it is below the UVLO threshold.

Other functions are unpredictable when VDDSMB is below the UVLO threshold.

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

ISL88731C does not function when VDDSMB is below its specified Under Voltage Lockout (UVLO) voltage. All of the SMBus registers in ISL88731C are powered by VDDSMB and are set to zero when it is below the UVLO threshold.

Other functions are unpredictable when VDDSMB is below the UVLO threshold.

Thanks so far, I've attached the new readings for PU200.

Note: In the image attached, the board I claimed to be "Good" Powers On and charges the battery normally. But isn't entirely good in general because it doesn't display. I'll start a new thread for that board as soon as i'm done with this current one.

There's no short in PQ202, PQ204, PQ203 & PQ205

[classicandy]

Re: Dell Inspiron 3521 [La-9104p] no power

ISL88731C does not function when VDDSMB is below its specified Under Voltage Lockout (UVLO) voltage. All of the SMBus registers in ISL88731C are powered by VDDSMB and are set to zero when it is below the UVLO threshold.

Other functions are unpredictable when VDDSMB is below the UVLO threshold.

By VCC, did you mean VDDP_LDO? because, that's the only pin with 5v on PU100.

Or probably, external 5v would more preferable.