No signal going to monitor - cannot boot blindly

[martg76]

 My HP Envy 700-210 is connected to a 23tm monitor via a DVI cable. I have not used this Desktop PC for a while (I was away because of the pandemic), but I need it now. When powering up the PC, the LEDs light up, but the monitor does not receive a signal. Because there is do not see the display, I cannot tell whether the computer is booting, updating, in BIOS, etc. I've tried pretty much everything suggested by the virtual support assistant, including connecting to another screen, different cables, a CMOS reset, resetting memory modules. etc.

The monitor has a DVI and an HDMI port, the desktop a DVI and a VGA port.

[Prométhée]

hi

from what I can see, from what you said, the computer has not been modified, no graphics card upgraded..

https://support.hp.com/us-en/document/c04058427
To have the same tower, obviously, you should have an HDD light, can you see it flashing / lit
if nothing here, the computer, most likely won't boot at all
how was the computer stored, was it plugged in, not at all etc?

[martg76]

Thank you for this helpful reply.

• The PC did not have electricity while I was away. It was plugged into a switchboard that was turned off.
• As far as I can see, there is no separate graphics card (the computer has not been modified).
• The red light on the front side of the tower is on when I turn on the PC. Is that the HDD light? The HDD seems to be running. (I can feel a vibration when touching it with my finger). I've already taken it out and put it back in as suggested by the virtual support assistant.

I'd be very happy about any further suggestions. Thank you!

[Prométhée]

hi no

if it is the same type of tower, that we have in the page that I indicated..
you have just above the compartment, with the button (normally here the cd player), and just below the on button, a blue light for the wifi, and right next to it a yellow light representing three or four discs, it should flash if there is hard drive access

it's quite rare, I've already seen that if the computer hasn't worked for a while, it can restart if you replace the CMOS battery, it's worth a try

[martg76]

Thank you again for this helpful reply!

It is the same kind of tower. However, I do not see a yellow or blue light (only the red light when switched on and the green light for the power unit in the back). Meanwhile, I've tried the following steps:

• I replaced the CR2032 battery with a new one as suggested, but there's no change.
• Figuring that something might be wrong with the DVI port, I got a VGA to HDMI adapter and tried connecting the monitor to it using an HDMI cable, but the monitor still goes to sleep.
• I also got a USB to HDMI adapter. Unfortunately this one requires a driver installation, which makes it useless in this case.
• Finally, I took out the hard drive and put it into an external hard drive case that I still had lying around. It works perfectly when plugged into the USB port of my laptop.

So maybe it is the connection to the hard drive? What can I do? I'm close to giving up.

[Prométhée]

yes, sorry, that doesn't seem like a very good sign
it looks like a corrupted bios/motherboard problem..
Not 100% reliable, but check, if you remove the memory modules (I don't know if you have one or two?)
does the computer give a series of beeps 3 long two short?

[martg76]

Thank you so much for your reply and for your patience!

• With the memory module out, the computer gives me a series of 5 long beeps. It starts again after a brief pause.
• Putting the memory module into a different slot does not change anything.
• Meanwhile, I've tried attaching the HDD to different SATA ports on the motherboard. On SATA2, 3, 4 and 5 the HDD light in the front lights up for about a second, and then goes out (otherwise there's no change). There's no light when the HDD is attached to SATA0 or 1.
• Booting the HDD from my external HDD case via USB also does not make a difference (but I do not know if BIOS settings even allow this).

So is the only solution to get a new motherboard? I guess I should probably get a new desktop.

[Prométhée]

So sorry

the last thing i can propose

replace the hard drive and memory module

https://support.hp.com/us-en/document/c03757575

Clearing the CMOS settings

try this

if nothing, try to find a specialist, who possibly could do other tests, and where to try a bios recovery
see what it could cost you, and depending, unfortunately, the replacement of the computer may be inevitable!
The replacement of the motherboard by the identical remains a possibility, but it can be random, I have seen users do it, but it was a failure, sometimes!