Hi,

I had a MXM graphic card type Nvidia K1000m from laptop HP8570w which had a broken capacitor.

The ceramic capacitor seems was broken and makes a short circiut. The laptop goes off because of the short-circuit. But it seems currently that only the capacitor C55 was broken on the graphcic card.
Because after I have desoldered it, the laptop runs with the card. But currently without this capacitor.
So to have full functionality and no instabilities I want to replace it with a new one.

So I need to know the value and voltage of C55 to replace...

Hello to all,

I have an old graphic card, which I tried to troubleshoot. The card is not providing a picture when turn on the PC.
I have checked 12V and 3.3V on the PCIe lanes and they are not shorted, but I have measured 6.5 ohms on the big power supply inductor (measured against the metal ground). Measuring nearby N channel MOSFETS 4C08N and 4C10N, I have found that MOSFET 4C08N has resistance 6.6 ohms between source and drain.
I also found one capacitor that has the same resistance over it.

I'm pretty sure this MOSFET is bad, since it should be kiloohms...

Hello,
I’m using a 10 µF, 20 V tantalum capacitor as a decoupling capacitor across a 5 V supply. When I power the circuit, the capacitor burns out.

At first, I assumed the tantalum capacitor was defective and replaced it, but the new one burned out as well when the circuit was powered.

I then replaced the tantalum capacitor with a 10 µF, 63 V electrolytic capacitor. This time, the capacitor did not fail after powering the circuit.

I do not understand why the tantalum capacitor burns up?

I tried to use this method:

Testing an N-channel MOSFET:

Step 1: Discharge the Gate (turn off the MOSFET)
Place the black probe (COM) on the Source (S) and the red probe on the Drain (D). The multimeter should show no continuity (high resistance or "OL" – open line).
Then, touch the black probe to the Source (S) and the red probe to the Gate (G). This discharges any stored charge in the Gate, turning the MOSFET off.

Step 2: Charge the Gate (turn on the MOSFET)
Now, place the red probe on the Gate (G) and the black probe on the...

hi,
this laptop works but temperature rise too much. I dismounted mb and cleaned well. There was a lot of dust inside.
I think that there is a graphic chipset issue because when I power the machine I get this error:
"the detected discrete gpu VBIOS is not meant for this system"
This make me think that maybe the gpu VBIOS has to be re programmed.
BTW someone already worked on this mainboard. Near graphic board there is Winbond flash memory that I think its stored the VBIOS.
I attach some pictures and one of message error I get when I power on the ...