China's top quality watchdog announced Thursday that Hewlett-Packard had violated China's consumer rights regulations and that its laptops did have faulty graphic chips and display screens.

The findings came out six days after the government agency launched the probe into HP laptops, a statement posted on the official website of the General Administration of Quality Supervision, Inspection, and Quarantine (AQSIQ) said.

The findings showed problematic graphic chips, which resulted in black screens, overheating and computer crashes, were found among HP Pavilion DV2000 and Compaq Presario v3000 laptops.

Defective display screens were also found with six HP laptop models, including the HP 541, the findings showed.

The U.S. company had not "strictly" obeyed the Chinese "Three Guarantees" regulations concerning after sales service, according to the findings.

The "Three Guarantees" are guarantees of a refund, replacement, and repair.

The AQSIQ had sent the findings report to the Ministry of Industry and Information Technology and the State Administration for Industry and Commerce, the statement said.

The three government agencies would closely monitor the company in implementing the regulations.

HP on Monday issued an apology to Chinese customers and pledged to extend the warranties for certain laptops.