Spotty wireless broadband connectivity for some of Apple's new iPhones most likely results from a hardware problem introduced during mass production, a Swedish technical magazine reported.
An Associated Press report said Ny Teknik, Sweden's foremost engineering weekly, obtained a report on tests conducted by unnamed experts that showed some handsets' sensitivity to 3G network signals is well below the level specified in the 3G standard.
The report said the most likely cause of the 3G problems is defective adjustments between the antenna and an amplifier that captures very weak signals from the antenna. This could lead to poor 3G connectivity and slower data speeds.
The iPhone 3G, which went on sale July 11 in the US and 21 other countries, was meant to offer faster web browsing than the year-old original model.
Since the launch of the next-generation iPhone, Apple's message boards have been flooded with complaints of dropped calls and poor 3G connectivity indicated by few or no 'bars' on the phone's display.
Some users said they performed side-by-side tests and found that the iPhone had connectivity problems in locations where 3G phones from other manufacturers did not. The reports were made by users who said they lived in the US, Canada, Japan, Britain and other countries.
Apple spokeswoman Natalie Kerris declined to comment on whether the problem lies in the iPhone's hardware or software, or with the various carriers' 3G networks, the Associated Press report said.