Dell Precision 3510 completely dead

[Andreasbest]

Hello.
Got a Dell Precision 3510 dead with burnt SIC530 mosfet.
Some copper traces are gone from the heat, 6, 7 and 8 pin are the same (Vin) and this is the easy part but it also lost pin 3 (N.C) and i'm not sure if and where i can bridge it.
I'm not sure if it's worth it our time that's why i ask you first before i order the mosfet.
Please check schematics and datasheet of SIC530 and let me know.
Thank you in advance

schematic https://www.badcaps.net/forum/showth...04#post1053304

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[Spider1211]

Re: Dell Precision 3510 completely dead

Hoping it did not fry your CPU, you could attempt to repair it. I would also replace the other components connected to it. Pin 3 is NC (Not connected), just leave it as is. Make sure to clean the soot properly before soldering on new components.

[Andreasbest]

Re: Dell Precision 3510 completely dead

Really? Now that's good luck.
What other components you mean?

[Spider1211]

Re: Dell Precision 3510 completely dead

The resistors (4R7, etc) and capacitors etc.

[Andreasbest]

Re: Dell Precision 3510 completely dead

The resistors (4R7, etc) and capacitors etc.

How can i check if there is a shortcircuit that cause mosfet to burn?
I think mosfet don't explode on their own, correct?

[Spider1211]

Re: Dell Precision 3510 completely dead

There are many reason as to why electronic components fail. MOSFET handle higher currents and are more likely to fail than components carrying signal (low power).

In your case, the MOSFET (both high and low drive) and the driver itself is all in one chip. With the chip removed, measure resistance to ground on Vin (pin 6). VSHW (pin 8) will show a low resistance because of the CPU which is normal. You should measure resistance to ground on all pins actually.

Replacing the surrounding components, especially the way the chip has failed, is good practice and as well as a precaution since you cannot be sure it did not sustain some form of damage which may not be immediately apparently.

[Andreasbest]

Re: Dell Precision 3510 completely dead

There are many reason as to why electronic components fail. MOSFET handle higher currents and are more likely to fail than components carrying signal (low power).

In your case, the MOSFET (both high and low drive) and the driver itself is all in one chip. With the chip removed, measure resistance to ground on Vin (pin 6). VSHW (pin 8) will show a low resistance because of the CPU which is normal. You should measure resistance to ground on all pins actually.

Replacing the surrounding components, especially the way the chip has failed, is good practice and as well as a precaution since you cannot be sure it did not sustain some form of damage which may not be immediately apparently.

Hello!
You mean these that i marked in red (attachment)?
I'll check resistance as soon i return to bench, meanwhile i order the MOSFET (5x just to be sure)

[Spider1211]

Re: Dell Precision 3510 completely dead

Yes. Also, although the other nearby capacitor and resistor looks OK, I would still replace them if possible.

Check the tracks properly before soldering new parts to make sure they did not break/crack, etc.

[Andreasbest]

Re: Dell Precision 3510 completely dead

There are many reason as to why electronic components fail. MOSFET handle higher currents and are more likely to fail than components carrying signal (low power).

In your case, the MOSFET (both high and low drive) and the driver itself is all in one chip. With the chip removed, measure resistance to ground on Vin (pin 6). VSHW (pin 8) will show a low resistance because of the CPU which is normal. You should measure resistance to ground on all pins actually.

Replacing the surrounding components, especially the way the chip has failed, is good practice and as well as a precaution since you cannot be sure it did not sustain some form of damage which may not be immediately apparently.

Hello Spider!
Finally the MOSFET lot i ordered is here so i can proceed with this.
So the Vin has only 3Ω to ground and full continuity.
Should i proceed to rest measures or the problem is here?

[Spider1211]

Re: Dell Precision 3510 completely dead

VIN (pin 6) of PU602 you mean? You are measuring with the IC off, correct? If so, 3ohm is too low and is indicating a short on that line.

Remove PL602 and/or PJP601 if present and measure resistance to ground on both sides (pin 1 and pin 2 of PL602).

Report back your readings.

[Andreasbest]

Re: Dell Precision 3510 completely dead

Yes pin 6, 7 and 8 (the same trace) of PU602, with burnt IC desoldered like in picture.
I can confirm left side of PL602/PJP601 (side of MOSFET) is shorted to ground.

[Spider1211]

Re: Dell Precision 3510 completely dead

6, 7 and 8 of PU602 are not the same. 7 is ground so short to ground here is obvious, pin 8 goes to CPU via PL603 and therefore low resistance is to be expected but pin 6 is VIN and should definitely not be low resistance.

Mosfet side (pin 2 of PL602) is around 3ohms, correct? What about pin 1?

[Andreasbest]

Re: Dell Precision 3510 completely dead

6, 7 and 8 of PU602 are not the same. 7 is ground so short to ground here is obvious, pin 8 goes to CPU via PL603 and therefore low resistance is to be expected but pin 6 is VIN and should definitely not be low resistance.

Mosfet side (pin 2 of PL602) is around 3ohms, correct? What about pin 1?

I measured according to datasheet but propably is reserved?

[Spider1211]

Re: Dell Precision 3510 completely dead

My bad, I was referring to schematic. What is the resistance on Pin 1 of PL602?

[Andreasbest]

Re: Dell Precision 3510 completely dead

pin1 15Ω

[Spider1211]

Re: Dell Precision 3510 completely dead

That's low. Just to confirm, you did remove PL602 and PJP601 yes?

[Andreasbest]

Re: Dell Precision 3510 completely dead

Yes pl602 is removed (pjp601 under pl602 is not soldered at all, pure copper)

[Spider1211]

Re: Dell Precision 3510 completely dead

Remove PJP603 (make sure you clean the pads properly) and measure resistance pin 1 of PL602 again.

[Andreasbest]

Re: Dell Precision 3510 completely dead

with pjp603 removed and cleaned 14.7Ω

[Spider1211]

Re: Dell Precision 3510 completely dead

Something is pulling +PWR_SRC down. From the picture it seems the soot extends to QV1. Try removing it and see if that changes anything. Otherwise you need to check around for damage.

Maybe try disconnecting +PWR_SRC jumpers on different power sections and see if that changes anything.

There is also the issue of low resistance (3ohms as you mentioned) on pin 2 of PL602.