Member Avatar for jerm3000

I am having troubles with my presarion 700 laptop. With the battery removed and AC plugged in I hit the power button and can hear everything turn on and lights light up and fans are on, but nothing is on my screen!!!! The cd-rom lights are working and I can open the drive tray just no picture. I have the directions to disassembly of the laptop and have completely taken it apart (very carefully) and placed everything exactly right back together to no luck of helping anything. Someone please help! I know my way around computers pretty well but this has me dumbfounded! :eek:

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Quick summary tied to the thread: the machine powers (fans, LEDs) but both the internal panel and an external monitor are blank (per ), so this points away from a simple backlight/LCD fault and toward power‑rail, firmware, or board‑level failure. Several members already suggested useful hardware checks; here are additional, practical diagnostics and safe next steps to narrow the fault without repeating the exact steps already tried. (toolsadvisers.com)

First, verify the power path before deeper board work: measure the adapter output at the barrel with a multimeter (compare with the rating on the brick) and inspect the DC jack and its solder points for cracks, melting, or loose pins—a charger that shows the correct voltage unloaded can still fail under load, so a swap with a known‑good adapter is ideal. Visually inspect the motherboard for bulging/leaking capacitors, scorch marks or lifted traces around the DC jack and power regulators; check for a short between the positive barrel and ground (continuity mode) before powering up. Use a current‑limited bench supply or a series lamp while powering the board to detect heavy draws and then thermal‑probe nearby components to find the hot culprit. (toolsadvisers.com)

If power rails check out, try clearing firmware/CMOS and HP’s emergency BIOS recovery options (they provide the Windows+B key combo and USB recovery methods that can restore a corrupted BIOS when the screen stays blank). Removing the coin‑cell CMOS battery for a few minutes or using HP’s recovery sequence can sometimes revive a unit that otherwise looks powered but won’t POST. Take normal ESD/power precautions when opening the case. ()

When those steps fail the fault is usually board level (GPU/NB, BIOS chip, or a shorted MOSFET). Professional board‑level diagnosis (thermography, reflow/reball where appropriate, or component replacement) is the safest route; reflow is often only a temporary fix and reballing or a donor mainboard is the reliable repair path. As noted by , removing removable cards has helped in a few Presario cases, so check mini‑PCI/phone/modem modules and any add‑on boards during isolation. (diy-laptoprepair.com)

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Member Avatar for BuggZ

Check out the troubleshooting section for your model laptop on HP's website. This is a known problem with several models of HP / Compaq laptops. Their advice is to upgrade the BIOS but that can't be done if the laptop won't post. Have you tried connecting the laptop to an external monitor to see if it is an LCD backlight problem? Try that and if you get a POST display then you have an LCD problem (either the backlight or the LCD close switch). If you still don't get a display try the following steps.
1. Remove battery
2. Disconnect AC adapter
3. Press and hold the power switch for 15 to 20 seconds
4. Connect the AC adapter and try to start the laptop.
If this works, check the BIOS and update if needed. If this doesn't work, try the same steps but remove the memory before pressing and holding the power switch (Step 3) and reinstall the memory before Step 4. If you still have no luck, you may want to try to check the processor. The 700s have been known to suffer from processor failures due to overheating. If your laptop has an AMD processor and you have access to a desktop computer with a later model Socket 462 processor socket, you should be able to test your processor with it. Just verify the motherboard will support your processor first. Hope this helps.

Member Avatar for jerm3000

Check out the troubleshooting section for your model laptop on HP's website. This is a known problem with several models of HP / Compaq laptops. Their advice is to upgrade the BIOS but that can't be done if the laptop won't post. Have you tried connecting the laptop to an external monitor to see if it is an LCD backlight problem? Try that and if you get a POST display then you have an LCD problem (either the backlight or the LCD close switch). If you still don't get a display try the following steps.
1. Remove battery
2. Disconnect AC adapter
3. Press and hold the power switch for 15 to 20 seconds
4. Connect the AC adapter and try to start the laptop.
If this works, check the BIOS and update if needed. If this doesn't work, try the same steps but remove the memory before pressing and holding the power switch (Step 3) and reinstall the memory before Step 4. If you still have no luck, you may want to try to check the processor. The 700s have been known to suffer from processor failures due to overheating. If your laptop has an AMD processor and you have access to a desktop computer with a later model Socket 462 processor socket, you should be able to test your processor with it. Just verify the motherboard will support your processor first. Hope this helps.

I tried hooking it up to a working external monitor, but that still did not work...it was blank too. I also tried removing the memory etc. that you suggested but nada is working. Soemthing weird going on because I think the monitor is fine, I am worried there is some connection gone bad on the motherboard. I was not able to test my processor though because I have no dektop to try it on.

Member Avatar for BuggZ

Reseating the processor may help. Make sure you get the socket locked properly and be careful not to damage any pins. You should also use a new thermat transfer pad or new heatsink grease before you reinstall the heatsink / fan assembly.

Member Avatar for wapa17

I had the same problem. (I needed to knock on the upside sometimes ;-)

Possible sulution: Since I removed the modem-card the system starts and works perfect .
OS: Linux & Win 98!

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