Dell E5440 completely dead - Page 2

**Andreasbest** · 10-19-2021, 12:45 AM

Quote:

Originally Posted by Andreasbest

Hello again.
PL5 one side is indeed grounded but i think is normal, all rest coils are fine, no shortcircuits to ground.

Indeed both sides are grounded, wrong measure before (probably probe needed some more pressure on lead)

**Sephir0th** · 10-19-2021, 05:02 AM

Ok. So it seems most of the parts on the supicious rail were checkd, except PQ5 and PU701, right?

**Andreasbest** · 10-19-2021, 05:43 AM

Quote:

Originally Posted by Sephir0th

Ok. So it seems most of the parts on the supicious rail were checkd, except PQ5 and PU701, right?

Seems so, what do you suggest?

**Sephir0th** · 10-19-2021, 06:09 AM

Unfortunately i can't find datasheet right no for PU701, but you can at least check whether 19V reach Pin1 and of course, you can check each pin for short to GND

**Spider1211** · 10-19-2021, 06:39 AM

How many amps is the board taking?

**Andreasbest** · 10-19-2021, 06:40 AM

5 6 7 14 15 & 32 are grounded
Pin #1 receives 19.5v

**Spider1211** · 10-19-2021, 06:41 AM

How many amperes? Do you have a bench power supply? If yes, set it to 19.5V and power the board from it.

**Andreasbest** · 10-19-2021, 06:41 AM

Quote:

Originally Posted by Spider1211

How many amps is the board taking?

You mean if i apply 19v directly to DC_IN?

**Spider1211** · 10-19-2021, 06:44 AM

Check where the DC adaptor connects to the motherboard. Apply power from your power supply on the DC connector pins, just make sure which is +ve and -ve first.

**Sephir0th** · 10-19-2021, 07:20 AM

PU701 Pin 6 & 15 short to GND means Main Power Rail short to GND. How could that Be missed before?

**Andreasbest** · 10-19-2021, 08:05 AM

Quote:

Originally Posted by Sephir0th

PU701 Pin 6 & 15 short to GND means Main Power Rail short to GND. How could that Be missed before?

Yes i can confirm pin 6 and 15 of PU701 are both grounded.
What do you suggest?

**Spider1211** · 10-19-2021, 08:10 AM

Do a visual check first to identify if something is physically damaged, otherwise Inject voltage on that line and see what gets hot. As always, start with 1V 1A then increase amp slowly if needed.

**Andreasbest** · 10-19-2021, 08:11 AM

Did visual inspection before, totally clean mb.
Gonna inject voltage and report in 2 mins

**Sephir0th** · 10-19-2021, 08:15 AM

First, Share exact Résistance to GND there in Ohms Mode, Range 200 or Auto-Range to exclude a Short with a step down Circuit.

**Andreasbest** · 10-19-2021, 08:19 AM

When i set it to Ω shows 20Ω not 0.

**Sephir0th** · 10-19-2021, 08:20 AM

20 Ohms are probably Bad News. Now you have to Check Resistance to GND of each coil. Look for a similar value...

**Andreasbest** · 10-19-2021, 08:40 AM

I see same value only on PL400 (both pins) all other coils have values way beyond this.

**Sephir0th** · 10-19-2021, 08:49 AM

That's fine then. So Voltage injection Like mentioned before. Pay Attention especially To PU401 and PU701.

**Andreasbest** · 10-19-2021, 08:51 AM

I inject voltage on pin 6 (+) and GND (-), 1v 1a and drown only 0.4A, no shortcircuit indication.

**Spider1211** · 10-19-2021, 08:52 AM

They both share a common line through PR400. You could try removing PR400 to see which side is 20Ohms.

I suspect it might be a faulty PU701. These are fairly easy to remove and resolder. I'd try removing it and see if the 20Ohms is still there. Or you could just inject voltage, but with 20Ohms at 1V, I doubt anything will get hot (expected 0.05A flow).

10-19-2021, 05:02 AM	#22
Sephir0th Badcaps Veteran Join Date: Oct 2020 City & State: Wangerland My Country: Deutschland Line Voltage: 230VAC 50Hz I'm a: Hobbyist Tech Posts: 318	Re: Dell E5440 completely dead Ok. So it seems most of the parts on the supicious rail were checkd, except PQ5 and PU701, right?

10-19-2021, 06:09 AM	#24
Sephir0th Badcaps Veteran Join Date: Oct 2020 City & State: Wangerland My Country: Deutschland Line Voltage: 230VAC 50Hz I'm a: Hobbyist Tech Posts: 318	Re: Dell E5440 completely dead Unfortunately i can't find datasheet right no for PU701, but you can at least check whether 19V reach Pin1 and of course, you can check each pin for short to GND

10-19-2021, 06:39 AM	#25
Spider1211 Badcaps Veteran Join Date: Oct 2019 City & State: Morcellement My Country: Mauritius Line Voltage: 230VAC, 50Hz I'm a: Knowledge Seeker Posts: 501	Re: Dell E5440 completely dead How many amps is the board taking?

10-19-2021, 06:40 AM	#26
Andreasbest Badcaps Veteran Join Date: Aug 2014 City & State: Around the country... My Country: Hellas ( Greece ) I'm a: Knowledge Seeker Posts: 731	Re: Dell E5440 completely dead 5 6 7 14 15 & 32 are grounded Pin #1 receives 19.5v

10-19-2021, 06:41 AM	#27
Spider1211 Badcaps Veteran Join Date: Oct 2019 City & State: Morcellement My Country: Mauritius Line Voltage: 230VAC, 50Hz I'm a: Knowledge Seeker Posts: 501	Re: Dell E5440 completely dead How many amperes? Do you have a bench power supply? If yes, set it to 19.5V and power the board from it.

10-19-2021, 06:44 AM	#29
Spider1211 Badcaps Veteran Join Date: Oct 2019 City & State: Morcellement My Country: Mauritius Line Voltage: 230VAC, 50Hz I'm a: Knowledge Seeker Posts: 501	Re: Dell E5440 completely dead Check where the DC adaptor connects to the motherboard. Apply power from your power supply on the DC connector pins, just make sure which is +ve and -ve first.

10-19-2021, 07:20 AM	#30
Sephir0th Badcaps Veteran Join Date: Oct 2020 City & State: Wangerland My Country: Deutschland Line Voltage: 230VAC 50Hz I'm a: Hobbyist Tech Posts: 318	Re: Dell E5440 completely dead PU701 Pin 6 & 15 short to GND means Main Power Rail short to GND. How could that Be missed before? Last edited by Sephir0th; 10-19-2021 at 07:23 AM..

10-19-2021, 08:10 AM	#32
Spider1211 Badcaps Veteran Join Date: Oct 2019 City & State: Morcellement My Country: Mauritius Line Voltage: 230VAC, 50Hz I'm a: Knowledge Seeker Posts: 501	Re: Dell E5440 completely dead Do a visual check first to identify if something is physically damaged, otherwise Inject voltage on that line and see what gets hot. As always, start with 1V 1A then increase amp slowly if needed.

10-19-2021, 08:11 AM	#33
Andreasbest Badcaps Veteran Join Date: Aug 2014 City & State: Around the country... My Country: Hellas ( Greece ) I'm a: Knowledge Seeker Posts: 731	Re: Dell E5440 completely dead Did visual inspection before, totally clean mb. Gonna inject voltage and report in 2 mins

10-19-2021, 08:15 AM	#34
Sephir0th Badcaps Veteran Join Date: Oct 2020 City & State: Wangerland My Country: Deutschland Line Voltage: 230VAC 50Hz I'm a: Hobbyist Tech Posts: 318	Re: Dell E5440 completely dead First, Share exact Résistance to GND there in Ohms Mode, Range 200 or Auto-Range to exclude a Short with a step down Circuit.

10-19-2021, 08:19 AM	#35
Andreasbest Badcaps Veteran Join Date: Aug 2014 City & State: Around the country... My Country: Hellas ( Greece ) I'm a: Knowledge Seeker Posts: 731	Re: Dell E5440 completely dead When i set it to Ω shows 20Ω not 0.

10-19-2021, 08:20 AM	#36
Sephir0th Badcaps Veteran Join Date: Oct 2020 City & State: Wangerland My Country: Deutschland Line Voltage: 230VAC 50Hz I'm a: Hobbyist Tech Posts: 318	Re: Dell E5440 completely dead 20 Ohms are probably Bad News. Now you have to Check Resistance to GND of each coil. Look for a similar value...

10-19-2021, 08:40 AM	#37
Andreasbest Badcaps Veteran Join Date: Aug 2014 City & State: Around the country... My Country: Hellas ( Greece ) I'm a: Knowledge Seeker Posts: 731	Re: Dell E5440 completely dead I see same value only on PL400 (both pins) all other coils have values way beyond this.

10-19-2021, 08:49 AM	#38
Sephir0th Badcaps Veteran Join Date: Oct 2020 City & State: Wangerland My Country: Deutschland Line Voltage: 230VAC 50Hz I'm a: Hobbyist Tech Posts: 318	Re: Dell E5440 completely dead That's fine then. So Voltage injection Like mentioned before. Pay Attention especially To PU401 and PU701.

10-19-2021, 08:51 AM	#39
Andreasbest Badcaps Veteran Join Date: Aug 2014 City & State: Around the country... My Country: Hellas ( Greece ) I'm a: Knowledge Seeker Posts: 731	Re: Dell E5440 completely dead I inject voltage on pin 6 (+) and GND (-), 1v 1a and drown only 0.4A, no shortcircuit indication.

10-19-2021, 08:52 AM	#40
Spider1211 Badcaps Veteran Join Date: Oct 2019 City & State: Morcellement My Country: Mauritius Line Voltage: 230VAC, 50Hz I'm a: Knowledge Seeker Posts: 501	Re: Dell E5440 completely dead They both share a common line through PR400. You could try removing PR400 to see which side is 20Ohms. I suspect it might be a faulty PU701. These are fairly easy to remove and resolder. I'd try removing it and see if the 20Ohms is still there. Or you could just inject voltage, but with 20Ohms at 1V, I doubt anything will get hot (expected 0.05A flow).

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