Dell Latitude E5570 Power but won't start

[Paul20]

Hi Guys,

Received that it showed no signs of life.
I inspect and I notice that there is a burnt component, exactly PU602 (sic530cd-t1-ge3) so I replace it, hoping it is soldered well, because a pad under the component was slightly damaged during the desoldering phase.
So I do a power-on test and the white Power LED turns on for an instant and then turns off immediately.

So I think there may be a BIOS problem, I load one found here, and from that moment the pc behaves like this:
White Power LED on, after a while the battery LED flashes orange 2 times and white 1, repeats this cycle about 8 times, then it seems to restart and goes on like this forever, and the fan spins strongly in the meantime.

I did some measurements and found both 5V and 3.3V, the USB ports are powered.
What I believe is the 13.5V base voltage.
Around the board there are then: 1V, 1.2V, 2.4V, 2.6V

I noticed a warm area also indicated by the thermal imager, which would be in the PU1301 area (ISL62771) I don't know if it's normal and I don't understand exactly which component heats up the most, around 35° in that area.

In the Dell led diagnostic guide, that pattern of leds is indicated as CPU problems, but I don't know if it really depends on that or not.

I want to clarify that as soon as the power supply is connected, the pc starts up by itself.
With or without cmos battery and main battery.

What else can I check? I accept advice.
Sorry if I didn't provide more precise measurements, but I'm not very experienced, and I listed the voltages I found lying around on the components.
Thanks to anyone who wants to participate.

[Sephir0th]

Re: Dell Latitude E5570 Power but won't start

In the Dell led diagnostic guide, that pattern of leds is indicated as CPU problems, but I don't know if it really depends on that or not.

Well, Since nobody of us a truth teller regarding the board number or the location of Semiconductor you have replaced, please take a picture of the board and show us, which component you replaced exactly. To start with.

i have the feeling, the diagnostics programm is on the right path this time.

[Paul20]

Re: Dell Latitude E5570 Power but won't start

I'm sorry I didn't enter the motherboard model: ADP80 LA-C641P REV: 3.0 A02
There are too many things to say and I forgot.
I attach a photo as requested.
I also noticed that, as soon as the PU602 chip was soldered, there was 5V between pin #4 and the capacitor as there is on the PU603 twin, now there is no more 5V on pin #4 of PU602.
I don't want the PU602 to be burnt again while taking measurements.
But in any case, even as soon soldered, the result was the one described initially.

[Sephir0th]

Re: Dell Latitude E5570 Power but won't start

Measure resistance to GND of PL603 or PL604, Ohms Mod (lowest setting), without power. Doesn't matter which one, since it is connected to the same load.

[Paul20]

Re: Dell Latitude E5570 Power but won't start

Multimeter set to minimum setting, 200 ohm.
Red test lead to GND, right?
Measurement 00.9

[Paul20]

Re: Dell Latitude E5570 Power but won't start

I noticed that there are several shorted capacitors.
These are capacitors in the vicinity of some coils, type PL1600, PL301, PL401 and some others.
How can I find a culprit of this short?
Could that be the cause of the failure?

[mon2]

Re: Dell Latitude E5570 Power but won't start

Careful on what may appear to be a shorted block of caps. These caps may very well be on a low voltage (ie. CPU) power rail. Respectively, by design, the power rail will be low in resistance.

Post the exact resistance to ground and also the cap locations for a review. As noted, the low resistance may be normal to that region of the logic board.

[reformatt]

Re: Dell Latitude E5570 Power but won't start

PU602 is DRMOS for VCC_CORE. Very likely a shorted CPU.

[Paul20]

Re: Dell Latitude E5570 Power but won't start

Unfortunately the capacitors are not marked on the motherboard, so I can't specify the exact location.

I checked the two capacitors right next to PL1600 and they give me 33.8 Ohms. ------- (From diagram PL1600 is +1.35_VRAMP)

Then one connected to PU301 and PL301 and gives me OL. ------- (From diagram PU301 and PL301 is +1VALWP)

Then another connected only to PL301 57.5 Ohm

Then another connected only to PU401 OL ------- (From diagram is +1VS_VCCIOP)

Then two more connected together with PL401 60 Ohm

I hope I took the measurements correctly.

[mcplslg123]

Re: Dell Latitude E5570 Power but won't start

Dont waste your time on this repair. Cpu is already fried due to PU602 being burnt.

[Paul20]

Re: Dell Latitude E5570 Power but won't start

Dont waste your time on this repair. Cpu is already fried due to PU602 being burnt.

[tirkan1971]

Re: Dell Latitude E5570 Power but won't start

Hi
i av the same issue. and i have a fried cpu. i try a lot, but under the thermal cam you can see hot cpu. sorry