At switchon the mother board bleeps continously for about 10 secs takes a break 5 secs then goes bleep again for another 10 secs and repeats the cycle reapetedly until switch off. All drives have been removed and the also the modem and still the bleeps keep coming, the cpu disconnected does inhibit the bleeps. Does this mean the cpu is damaged? even the memory removal does not inhibit the bleeping.

You probably somehow killed the screen. Did you drop it or bang it into something? You can try downloading and replacing the drivers, but I doubt that will help. Lines on the screen are usually a physical problem, not software related.

You may try a Windows Restore if your machine has that ability. Some do, depending on who you bought it from. Again, doubful it will help, but worth a shot.

Need more information on the bleep. When does it bleep? Constantly? When you touch the screen? Or when you boot it up? What kind of bleeps? One? Several? Long? Short? Both? Repeating sequence?

Disconnect the negative battery terminal and wait 10 minutes. Reconnect and try to retract it again. Let us know how it goes.

Hard to troubleshoot with just this info, the red light can be helpful if its 10 blinks repeating over and over replace the power supply first then the A board. Voltages check on the power supply would narrow down the culprit.
Post again if you measure the power supply voltages

I’m happy to help further over the phone at https://www.6ya.com/expert/eric_ab7c09ec01841771

Please check this link

check whether motherboard has inbuilt speaker or speaker connected externally.
Externally means check the proper connection is given for the speaker.
If speaker is connected externally in proper manner still no beep means problem is in the external spaeker

We have the same problem!

child lock activated press start button for 5 secs or more will release refer to manual for info.

Remove all handset batteries and leave for 10 minutes.
Unplug main cradle and reconnect after 30 Seconds.
Replace all handset batteries and place handsets back on cradles.

With ignition off, press and hold button for trip mileage, then put on cignition and hold for about 10 secs, when the display should clear and you should hear a BLEEP, then release the button, You must release the button within 4 seconds of the BLEEP. Switch off ignition. Then switch ignition back on, should be clear.
Hope this helps

Try this one:

http://h20000.www2.hp.com/bizsupport/TechSupport/SupportTaskIndex.jsp?lang=en&cc=us&taskId=110&prodTypeId=12454&prodSeriesId=472275