Member Avatar for mitchreef

I have a Presario 700 which went dead screen on us. The LED's come on and I can hear the fan and harddrive running. I connected an external monitor and still nothing. I did the full power down with no battery or AC and held the power button 15 seconds, zip. I unseated the memory and powered down again, nada. I disassembled the machine and reseated the processor, still nothing. Any help? What next, a new Motherboard? It was replaced once already for unrelated problems. VERY frustrating.

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This thread points to a classic laptop symptom: power but no video. has already explored some basic possibilities and plans a reflow; and added helpful reminders. Below are practical, low-cost checks and cautions that narrow the fault before attempting a heat-based fix, plus safe alternatives and salvage options.

  • Look for POST activity signs that don’t rely on the screen: power LED blink patterns, HDD activity LED cycles, keyboard Caps/Num Lock toggles, and internal speaker beeps. Deliberately force a POST error (remove all RAM) to generate beep codes if the system speaker is present—absence of any POST indication points away from a simple GPU solder crack.
  • Do a visual inspection under good light: swollen or leaking electrolytic capacitors, scorch marks, cracked solder fillets (especially around the GPU/VREG area) and loose connectors are common, fixable faults. Wiggle the DC jack and display cable gently while powered (briefly) to see whether LEDs change—this helps locate intermittent solder/jack faults.
  • Reset CMOS by removing the coin cell for a few minutes and try booting with the HDD and optical drive removed; that rules out peripheral hangs. Try each RAM module alone in every slot or a known-good module if available.
  • Multimeter checks: if competent with electronics, verify main power rails (standby 3.3V/5V, CPU core rails) at the board’s test points; absent or out-of-spec rails indicate regulator or power-IC failure rather than a pure video-chip issue.

Reflow notes and cautions: hot-air “reflows” can give temporary life but often fail again and risk collateral damage. If choosing that route, remove the board, use proper flux/preheating and a rework station or oven profile rather than a hairdryer, and expect a temporary patch unless a full BGA reballing is performed. Given cost and reliability, weigh replacement motherboard or salvaging usable parts (RAM, CPU, HDD, display assembly, charger) as often the most economical choice.

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Member Avatar for mitchreef

Anybody?

Member Avatar for mack00234

If it's a desktop:
If you have a video card, try taking it out and connecting to integrated graphics.
Otherwise:
IDK.

Member Avatar for mitchreef

It's a laptop. I had a friend look at it and he said it's the motherboard video chip. I'm going to try to reflow it and if it doesn't work I will replace the computer. It's been nothing but trouble every since new.

Member Avatar for yuanshunzhen

have you did the full power down with no battery or AC ?

Member Avatar for mitchreef

I tried all the diagnostics then sent it to a friend who is a repair tech. He said the Mother Board is bad and the computer isn't worth spending the money on (AGAIN). I'm going to take it apart and try reflowing the video chip. Maybe it will work, maybe not, but all it will cost is a little effort.

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