hey guys, hoping for some pointers to repair an eBay bought "faulty" laptop.

Ill try and give as much info as I can.

Dell Inspiron 17 (7786) Laptop
Service Tag: 5J0NHT2
Bios: 1.9.0

When I received this , it would only flicker on the KB backlight for a second, then off and on.
Then it started getting weirder!
Sometimes when attaching the AC power supply, and pressing various pre-boot diagnostic keyboard keys... it did try to boot, in fact out of a hundred attempts, the laptop did actually boot into the Bios ! but never has...

Hi everyone, I have an Inspiron 7506 laptop I've had for a few years, and it'd occasionally have a problem where after I'd power it off, it wouldn't turn on again unless I disconnected, drained residual voltage by pressing the power button, and reconnected the battery. It now seems to be occurring every single time I shut down the laptop and attempt to turn it back on again. I have done all the common troubleshooting steps, such as completely disconnecting the battery & CMOS battery and draining the voltage and leaving it for an hour, and I've even replaced the battery. This is definitely...

Hello everyone,
I've recently gotten my hands on a defective XPS13 9380. I will attach a zip of the schematics and boardview.
My first discovery on the Board was that the reverse current Diode PD103 of the 1st USB-C was blown.
Nothing to worry about, the board got 3 USB-C ports which support Power/Charging. On I go.
Next I inspected the power-rails to see why the diode blew up and found a short on the 3V3 rail which I traced back to the Power-IC for the LCD (UZ2). I desoldered it and the very low-ohmic short is gone. I checked on the LCD-connector that there's no short...

Hello
I have a big problem and that is that in some cases when repairing active pfc power supplies I cannot work with a test lamp. I can only get help with 5 volts standby and for starting and starting I have to work without a lamp and this way there is a possibility of parts exploding and other parts being added.
Sometimes with a multimeter test the problems can be reduced to some extent, but I had several cases that had to be tested on and online and recently two varistors exploded. They had terrible resistance because the power supplies were over 800 watts.
Is there a way...

This one's a weird one, and still unsolved despite it having gone back to Dell once.

Specs

i7-8750H, GTX 1060 Max Q, 500GB SSD & Seagate 7mm 1TB HDD. 17.3 IPS screen. This has the fingerprint reader in the power button.

Backstory

I bought this from eBay, from a wallpapering shop. £650 in 2020 which was a good price considering it's a gaming laptop. Physically it's in perfect shape, apart from the hinge mounts on the palmrest failing in the time I've had it (I have a new palmrest for it). The usual thin plastic crap modern build quality!...