Rather unfortunate you had to face difficult times in your life and now with your system. However, please understand that any electronic product is subject to failure, while a few may fail in the early days, some last for years.
The 7 beeps refers to a cpu failure - I would suspect a faulty motherboard, as the cpu is seated on the motherboard, as seen in previous cases - see this link for more info about beep codes - http://dell.to/1IuETMX
You could download the service manual - http://dell.to/28VFmMB - and reseat the memory modules and check if the system powers on. Sometimes it helps in the rarest of cases.
I have also confirmed there is no warranty on the system. At this point, your option to fix this system is a paid service call. Dell would not repair a system without any charge if the system is not under warranty - this is as per the consumer laws in your country.
Write me a private conversation with the service tag and your contact details(Name and Email) for case records.
Let us know if you have any other queries.