After a quality problem involving laptops produced by Hewlett-Packard (HP) was recently exposed in China, phony service centers are lapping up business from the brand's troubled users.

On March 15 - Consumer Rights Day - HP China apologized to its customers and promised to resolve the service problems within 30 days. Problematic graphic cards, which resulted in black screens, overheating and computer crashes, were found in certain models that included HP Pavilion DV2000 and Compaq Presario V3000 laptops.

The number of unauthorized service centers quickly boomed in the capital to take advantage of the opportunity.

Zhuo Lihua, a Beijing college student who last December bought an HP laptop in Zhongguancun - the largest PC and laptop shopping center in Beijing - said she has already repaired her laptop twice.

"I bought my HP laptop because it was a famous brand and on offer at a good price. I have now spent 1,500 yuan repairing it," said Zhuo, who went to Top City Computer Shopping Mall in Zhongguancun on Monday to deal with an authorized HP repair center.

More than 100 customers crowded the service center on Monday afternoon, waiting for repair work or replacements for their faulty laptops.

However, the technology market is reportedly also packed with numerous private companies masquerading as legitimate service centers.

"There were so many repair shops claiming to be authorized HP centers that I was confused where to go," a customer surnamed Zhang told METRO.

Zhang first journeyed to an "official HP service center" in Zhongguancun last week to be told he would need to pay 2,000 yuan to change his graphics card. He ignored the suggestion and located the genuine service center, which then replaced the part for free on Monday.

In the same shopping mall, some shops were promising customers they would keep repair fees as low as possible.

"There is no difference between us and the official service centers," said a shopkeeper who refused to reveal his name.

"If your laptop has passed its guarantee period, you will need to find the cheapest price possible," he said.

"Laptops that have been repaired or had parts changed by unauthorized shops will not be refunded or replaced," a male service employee of the authorized HP service center told METRO.

"However, we will still apply to HP for the repair of affected laptops, even if they were repaired in unauthorized shops," he added.

Isaiah Cheung, global vice-president of HP, said last week that HP would provide maintenance service or recall problematic HP computers, based on the "Three Guarantees" of repair, replacement, and refunds for substandard products.

On Friday, China's top quality watchdog, the General Administration of Quality Supervision, Inspection and Quarantine, announced that HP had violated China's consumer rights regulations.