Member Avatar for gingerwinger

Hello All

I have stupidly touched the motherboard of my lappy and it sparked and now only the CPU fan works and it wont do anything else. I was touched the screen connector port on the board as the screen was staying white so I thought it had a loose connection. Now nothing works. Is this repairable or should I buy another board?

I have seen one on Ebay but it says there is scrolling W's on boot. Is there a problem with this board also?

I appreciate your help

Gin

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Dani AI

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A spark while probing a powered laptop usually means a direct short on one of the power rails. That can be anything from a blown tiny SMD fuse or MOSFET to damage farther down the power-distribution path. Since already checked capacitors under a microscope, that makes a total capacitor failure less likely — which is encouraging. The next step is a focused, measured diagnosis rather than repeated power-ups (those can make damage worse).

  • With all power removed, visually inspect the DC jack, the screen connector area and nearby components for tiny scorch marks or melted solder.
  • Verify the adapter output at the jack off the board. Then, with the board unpowered, use a multimeter (ohms/diode mode) to check for a low-resistance short between the main input rail and ground; very low resistance suggests a shorted MOSFET/regulator or blown protection device.
  • Probe for continuity across any nearby SMD fuses (look for parts marked F or small rectangular parts) and check MOSFETs/diodes around the DC-in and GPU/CPU power area.
  • Try a minimal-boot test (battery/HDD/optical removed, single RAM stick) and an external monitor to rule out the screen/cable as suggested. No POST but fan spin usually means some rails exist while others are dead.

BIOS corruption from a single short is possible only if the flash chip or its supply rail was hit; removing the CMOS cell rarely helps a physically corrupted flash. If power-rail components are intact but the board still won’t POST, professional reflash or chip-level repair may be required.

Board-level repair shops can often replace blown fuses or MOSFETs cheaply; full southbridge/CPU/GPU damage is expensive. If buying a replacement board (used), match the exact part number and board revision and avoid listings with boot-artifacts (the “scrolling W” symptom warned about). If unsure about measurements or solder work, get a professional diagnostic to avoid throwing good parts away.

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Member Avatar for jbennet

You mean you touched the motherboard with the screwdriver when it was on !?!

your supposed to unplug and remove the battery before dismantling!

Dont buy taht one of ebay. It looks broken. Most likely wouldnt fit your laptop anyway. I think youl most likely need a whole new laptop

Member Avatar for gingerwinger

Yes it was on and I know its a no no but I was not thinking and thought I could quickly check the cable. I know I'm stupid

So what could have gone to make it un-repairable?

Member Avatar for jbennet

Short Circuited it?

Member Avatar for gingerwinger

Thanks for the reply

Could it have damaged the bios as everything looks ok on the board as i have looked at it under a microscope and can't see anything damaged. Are there fuses that could have blow?

Member Avatar for jbennet

Check the capacitators - are any leaking?

Member Avatar for gingerwinger

No they are fine.

Thanks :-)

Member Avatar for dewabo

Hello All

I have stupidly touched the motherboard of my lappy and it sparked and now only the CPU fan works and it wont do anything else. I was touched the screen connector port on the board as the screen was staying white so I thought it had a loose connection. Now nothing works. Is this repairable or should I buy another board?
You shorted out the screen, if you could replace the screen the rest might still be working.

Member Avatar for gingerwinger

The capacitators look fine as I have look at every single one under a microscope. Found another board from a used laptop so hopefully it will work!

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