Member Avatar for bilbao

Question: How does it look a laptop motherboard fuse.
I have a hp compaq 6715 s, bought with a few bucks from someone who tried to charge it with an acer compatible charger ( same voltage, same amp.) now is dead and i think is a fuse or something. can someone give me an ideea?

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Practical troubleshooting notes for an HP Compaq 6715s that won’t power up — follows the points made by , , and and focuses on verifiable tests that separate adapter/DC‑in faults from board-level failures.

  1. Verify the adapter off the laptop: measure DC voltage and polarity at the barrel with a multimeter and confirm it matches the adapter label. Repeat the measurement under a modest load (lamp or resistor) or compare with a known‑good HP adapter.
  2. Inspect the DC jack and surrounding PCB pads for cracked solder joints or damaged traces; many failures are mechanical.
  3. With the battery removed, apply mains adapter and measure at the board’s DC‑in test pads (service manual locates these). If the adapter voltage appears at the board input but downstream system rails (3.3V/5V etc.) are absent, the fault is in the power‑conversion chain.
  4. Do a continuity/ohms check (power removed): a very low resistance between main + rail and ground suggests a shorted regulator, capacitor, MOSFET, or TVS diode near the input. Isolating sections by lifting one end of a suspected SMD component helps find the short.
  5. Visual inspection under magnification often shows the culprit — bulged capacitors, blackened SMDs, or a burst TVS diode close to the jack. Common replaceable parts: DC jack, resettable polyfuse (or fusible resistor), input MOSFETs/diodes. PMIC or EC failures are harder and usually justify a donor board or professional repair.

Safety/caveat: follow ESD precautions, remove battery and mains before probing, and only perform live voltage checks if comfortable. A current‑limited bench PSU is very useful for diagnosing shorted inputs without destroying parts. Measured voltages at the DC‑in and main rails, plus close-up photos of the input area, will generally pinpoint whether the repair is a simple part swap or a board‑level fault.

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Member Avatar for forumdude123

how about not opening it up and saving your self an electrical shock

Member Avatar for loki_

i am not a laptop technician but as far as i know it does not have a fuse, when your laptop does not want to power up you have to start from a point(the power) is it plugged in? does the ac adapters power light come on?(if it has one) does the charging light on the laptop come on when you insert the charger? if yes then the problem is internal(maybe power connector on the mainboard, if no light comes on the you have a blown or faulty charger! try and get a nother one just to test it!

Member Avatar for bilbao

ok. 1st : i have electricity at home, loki_ , forasmuch i can reply now. 2nd: i have completly disassembled my laptop. i have consulted the service manual, the schematic, etc.... and i have learned that some laptops have an internal protection such a small fuse, resistor, something..., others don't have. Actually the question is: has my HP such a protection?. The ac adapter was changed with a "compatible" one. From now on, no power light, no sound. It is clearly something is broken, and yes i have tested the connector conductivity on the mainboard with a digital multimeter and is ok. My only chance is to change this pseudo-protection zone, chip, component (however the jappanese have named it.) if it has, since the electrical shock was not so powerfull to pass it.

Member Avatar for james.pearse

I have an an HP Compaq 6715s that was working last night but is dead this morning. The battery is fully charged as the light is green on fromt of laptop when the charger is plugged in.If you press the start button with psu connected nothing happens. If you remove the psu plug and press the start button the lights on the front flash on for a few seconds then die. I have tried to run laptop with battry removed and psu connected but it appears to be dead. Has any one any suggestions.

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