HP Compaq NC6400 laptop - Problems since trying to increase memory.

grumpycrab

If you're seeing nothing on the screen at all but you think its running then you need an external monitor/TV to see if its a problem with the laptop display.
When you use the on/off switch is that a single press (in which case the computer may be just going to sleep rather than shutting down) or do you long press (5 seconds) which forces a proper shutdown.  It may be worth trying the latter (but you don't want to do this too many times as its a rather abrupt shutown).

PaulR2020

I believe the laptop is booting to the logon screen as it is making all the right noises. All lights you would expect to be lit are lit. How do you shutdown a Windows 7 computer at the logon screen just using the keyboard? All my searches online seem to be only offer advice from a logged in computer. Thanks.

poppellerant

Try holding the Fn key and tapping F4 once before releasing Fn and wait a few seconds.  This switches between the internal display and external display.  If this doesn't work, try the obvious - adjust the brightness.  If adjusting the brightness doesn't work, then try and connect the laptop to another monitor

If none of the above works, I would go back to basics and try your old RAM one stick at a time.  If one slot doesn't work, move the same RAM module into the other slot and test again.  If the first 1GB RAM stick doesn't work, move to the second 1GB stick of RAM, again alternating between slots as needed.  Hopefully one of the RAM sticks will work in one of the slots.  One you've tested the 1GB sticks, test the 2GB sticks as it may be possible these are faulty.

PaulR2020

Tried Fn/f4 and brightness as suggested, no change. Regarding memory module testing (2x1Gb, 1x2Gb), can I try just using the slot under the laptop, leaving the one under the keyboard empty? It’s much easier to swap the module in the slot under the laptop than the one under the keyboard. I’ve ordered a VGI cable and will test the laptop connected to the tv.

HereToday

https://support.hp.com/us-en/document/c01997899

But fourteen years old. Let it go. All your data is retrievable as you can remove the HDD and place it into a caddy.

USB 2.0 https://www.ebay.co.uk/itm/USB-2-0-SATA-Hard-Drive-Enclosure-HDD-2-5-inch-External-Case-Caddy-UK-Black/402365591142

USB 3.0 https://www.ebay.co.uk/itm/USB-3-0-2-5-Inch-Hard-Drive-Enclosure-SATA-HDD-SSD-Caddy-Case-For-LAPTOP-PC-DVR/154226590077

Find a more modern laptop, second hand if on a tight budget and fit an SSD within.

What can you afford, if anything? Don't bust your budget; stick to what you can actually afford and we'll see what we can find.

CoastingHatbox

Is there no display at all on the laptop, right now?

I think that's what I garnered from your recent updates. And just to clarify, is the display completely off as the laptop is booted? There's no BIOS flash screen or anything displayed as part of the boot process when it is turned on, after a long press of the power key to turn it off?

Do you have access to another computer? Do you know if you had the Windows Firewall disabled, or your local network set as trusted?

Perhaps, if you have a smart phone or tablet, when the laptop is switched on, can you login to your router with the phone/tablet and see if the computer is listed as a network client on your LAN? This would at least confirm that the problem is a graphics problem and the machine is booted in some way shape or form (unless it is booting into safe mode).

This could be a physical problem with the LVDS connector that connects the laptop screen to the motherboard, it could be a graphics driver problem, an issue with any component of the graphics software or something else entirely. Plugging it into an external display and it still not displaying anything would rule out the first issue, at least.

PaulR2020

Hi
My budget could be up to £500. I only really use the laptop for browsing and Microsoft Office (Word, Excel) for personal use, not work related. I don’t really play games but don’t mind if it’s possible with this budget. 

There is absolutely no display at all, during the startup, right up to the login screen. The display is completely black the whole time. From your suggestion, I can see the laptop connected to the hub, so it must be starting. I had the firewall disabled. I believe I just had Defender running. I don’t have access to another Windows PC. Not sure about the “trusted network”. I am still waiting for the VGA cable to arrive and will report back when I try connecting the laptop to the tv.

Many thanks for your continuing interest and support here. Its much appreciated.