I Cant connect probook4510s via hdmi to tv. I have 2 probook4510s 1 with the original windows xp and another one that i installed windows 7 on it. When i try connecting the hdmi cable to any both of them the tv shows no image. i tried Cycling on the screens but nothing happens.

You cannot have the TV as a wireless monitor for a XP machine.
Your ROKU TV will have HDMI input, but XP dos not have the ability to produce HDMI.
Using the composite input via a converter from the VGA output is possible.
see such a device here.
C2G VGA to Composite PC TV Video Adapter

old DV5-2125 (circa 2010 carbon dated, IIRC)
its bad? the port. or. do tests. tests solve problems.
try it on 2 TV's yet, be smart.
is this windows 7 (or dead XP./vista) or w10, i cant guess that.
did you use a real HP driver, from HP and not virus sites? (endless)
HDMI is just in front of eSata port. do not mix those. (working in dark)
try new cable.?
load the real drivers seen here?
only these work. shipped windows 7, is it still W7 or w8 or w10
last year did you upgrade to W10, gee, be like question1.

this pc had intel or amd drivers, new. only the correct one works.
learn too that underlaying drivers can fail killing this too.
hint load them all , and do not mess with FLASHING BIOS !!
this PC is like 2 PCs, totally different, getting the correct driver
is not easy,. HP can guide you, but you picked fixha, why here>


https://support.hp.com/us-en/product/HP-Pavilion-dv5-2100-Entertainment-Notebook-PC-series/4210545



here is real HP, ask them how to match drivers.
sometime even the full service tag must be told to them to get a match up, (For sure Intel, AMD , classed mobo variances.)

https://h30434.www3.hp.com/

the flicker will be the pc you have a low voltage on the hdmi board were by the voltage is up and down causing the flicker. could be a low volt on the psu or in the graphics card itself. graphics cards use a lot of power. could just need removing and given a good clean.

The TV can't process the digital signal. It might be out of range.

No sound from the t.v., or no sound from the computer speakers? HDMI is a video only connection if you want sound from your t.v. you will have to connect from your laptops headphone jack.

Assuming you are using Windows XP, here is a link to a Microsoft article outlining how to enable the second monitor. The only thing I would add is that once you get into the properties window, your second monitor may show up darkened out. If it is, you need to right-click on it and select "Attached" before continuing on:

http://www.microsoft.com/windowsxp/using/setup/hwandprograms/monitors.mspx

Keep the graphic resoultion to 800*600.

Sound doesn't travel to you tv via a hdmi lead from your laptop, you would need to use laptops speakers, or a connect the laptop to a suitable audio device.

i had the same problem, you need to right click on the desktop when the hdmi lead is plugged in, go to personalize, tasks, option to connect to a projector or other external display, and connect external display only. the blu ray cant play on 2 screens at the same time. my only other problem is that on some blu ray discs, i get as far as the title screen and then cant press play in any way, can anyone help???

Please provide the driver link to the ATI HDMI applications. its a known problem from ATI