Dell XPS 13 9370 CAZ60 LA-E671P zalany, brak ładowania

- Measure the resistances to ground on pins 5, 7, 9, 11, 12 of PU300.
- Measure the resistance between pin 1 and pin 2 of PU300.
- Measure the resistance between pin 6 and pin 10 of PU300.
- Measure the resistance between pin 14 and pin 15 of PU300.

PU300 resistance to ground:
pin 5 - 25kΩ
pin 7 - 25kΩ
pin 9 - 0.7MΩ
pin 11 - 23kΩ
pin 12 - 4.5MΩ
resistances on PU300:
pin 1 to pin 2 - 2Ω
pin 6 to pin 10 - SHORT
pin 14 to pin 15 - 6.3Ω

THANKS

adysowski napisal/-a:resistances on PU300:
pin 1 to pin 2 - 2Ω

This resistance should be around 4,4Ω.
Check the resistors PR323, PR324 (both should be 2,2Ω).

When resistors are desoldered both are 2.2Ω - they are okay as i replaced them few times. When are soldered the PR323 resistor has 0Ω, between 1 and 2 pin of PU300 there is still around 2Ω. Thats what i mean by short to B+ earlier

adysowski napisal/-a:When are soldered the PR323 resistor has 0Ω

Please, post a clear picture of resistor PR323 area of the board with a nearby surroundings with the resistor PR323 removed from the board.

Okay, here is photo with nearby of PU300 - as i mentioned before - traces were burnt out, thats why there is reconstruction. Thanks Even without resistor PR323 top leg of PC346 has 0Ω to B+.

I asked for a clear picture, but this one is not clear at all.
The copper traces on the board must be clearly visible in the picture.

I hope now its better

Sorry, but your pictures are now blurry.

For optimal picture quality, you need to set the external light source at an appropriate angle and set an optimal light intensity.
It sometimes help, if you flood the charger chip area with IPA and take a picture of flooded area.

By the way, if you save the pictures from the microscope directly to the SD card or computer, you got a better quality than if you take a picture of the microscope LCD screen.

The earlier photo was saved directly to PC from microscope I dont have any better camera, i can make a photo from my smartphone, but the smaller components wont be much more visible. Maybe these are better:)

Please, remove all that mess from the board (all components and jump wires highlighted in yellow). Then clean the area and post a clear picture of the same area of the board with the components removed.

Okay, i removed these components and jumper wires - I used IPA to make photo better

Solder 5 missing components (marked yellow) and connect them with a jump wires (marked red) as shown in the following picture.

1= Capacitor PC346= 4.7µF/25V, package 0603
2= Capacitor PC345= 1µF/25V, package 0402
3= Resistor PR323= 2.2Ω/1%, package 0402 (you can also use a 5% resistor)
4= Resistor PR330= 100Ω/1%, package 0402 (you can also use a 5% resistor)
5= Capacitor PC322= 10µF/25V, package 0603

Sorry for such a long time without reply - had to wait for component delivery from china.. After replacing PU300 IC, soldering missing components You marked before laptop starts after plugging in AC adapter, but shuts off after few seconds and pressing power does not turn it on again. I hear a lot of noise from Charger IC (PU300). What should i check? 19.5V, 1.0V IOP, 1.0V DRAM, 3.3ALW, 5V are present. CPU and RAM chips are heating up when laptop try to start. After holding power button for 30 seconds the lights under touchpad are fast blinking 3 times then laptop shuts off. Every time when AC adapter is connected laptop tries to turn on. Every time power on LED light is present charger makes noise. Any ideas? Thanks

Perform the following measurements with the power supply connected to the port JUSBC3:
- Measure the voltages to ground on pins 1, 4, 8 of transistors PQ153, PQ155.
- Measure the voltage to ground on coil PL301.
- Measure the voltage to ground on any pin of resistor PR304.

PQ153
pin 1 - 1.8V
pin 2-4 - 19.7V
pin 8 - 19.7V
PQ155
pin 1 - 19.8V
pin 2-4 - 19.8V
pin 8 - 19.8V
PL301
7.8V
PR304
9V


Thanks

adysowski napisal/-a:PQ153
pin 1 - 1.8V
pin 2-4 - 19.7V
pin 8 - 19.7V
PQ155
pin 1 - 19.8V
pin 2-4 - 19.8V
pin 8 - 19.8V

Your pin count seems strange. Pins 1, 2, 3 are connected together and also pins 5, 6, 7, 8 are connected together.

Okay, i looked at the schematics where i have only 5 pin so misunderstood. I fix this now:
PQ153
pin 4 - 1.8V
pin 1-3- 19.7V
pin 5-8 - 19.7V
PQ155
pin 4 - 19.8V
pin 1-3 - 19.8V
pin 5-8 - 19.8V

It looks like PQ155 is having 19.8V at all pins. Does it mean it is bad?

adysowski napisal/-a:It looks like PQ155 is having 19.8V at all pins. Does it mean it is bad?

Yes, exactly.

After desoldering PQ155 and PQ150 I still have 20V on pin 4 PQ155 pad. After desoldering PR261 i have 1V (with PQ155 and PQ150 desoldered). What can be the issue? What voltage should be on pin 4 of PQ155? Thanks