As RIM claims it has traced source of BlackBerry's problems, fans flock to test rival

With BlackBerry still reeling from a catastrophic communications blackout that left millions of smartphone users worldwide unable to receive emails this week, its rival, Apple, is expected to reap the benefits. The timing of the release of Apple's new iPhone 4S, which goes on sale at 8am today, could not be more fortuitous.

A small handful of die-hard disciples had already staked their place outside Apple's flagship Regent Street store in London yesterday afternoon to be first in line to get the new phone. "I've had it with my BlackBerry," Helen Yemane, 17, said from her deck chair, firmly planted in the Regent Street queue. "I'm going to throw it at the wall. It stopped working for three days, it was so annoying. I'll be replacing it with the new iPhone." Although derided by some critics as a half-baked replacement for the iPhone 4, the faithful were in no doubt that the latest offering from the California tech giant would be worth the wait – and the £500 price-tag. Pre-ordering for the iPhone 4S began on Monday and hit a million in a single day. It is the first new Apple product to be released since Steve Jobs, the company's talismanic former chief executive, died last week.

"Jobs was my idol. I cried when I heard he had died," said Craig Fox, 30, who had queued since Sunday night to be first in line for the new phone. Naturally, he brought his Apple MacBook computer with him and has been sleeping with it in his sleeping bag for safety. "Apple products are the pinnacle of engineering and design," he said. "They're symbols of our time. That's why I'm here."

Fans were initially underwhelmed by the iPhone 4S, hoping for a more comprehensive update – the expected iPhone 5. But today's new release does contain some new and improved features, including an eight-megapixel camera and new voice-command technology called "Siri".

After millions of BlackBerry customers found that their phones did not work earlier this week, the scene was rather more stark at the European headquarters of its Canadian manufacturer, RIM. The large grey building among a row of equally unremarkable industrial units in Slough seemed a world away from the sleek glass frontage of the Apple Store and not like the sort of place that would be at the centre of international controversy.

The BlackBerry blackout has been traced to a server failure, reportedly at RIM's Slough HQ. Inside, an army of engineers was mobilised to fix the problem that resulted in browsing, email and other services being unavailable for most of the company's seven million British customers – and still more in the Middle East, India and Africa.

A source at the BlackBerry manufacturer said: "Our people have just not stopped work on this."

Estimates suggest enough unsent data has accumulated to fill nearly 2.4 trillion music CDs. Nick Dillion, a mobile phone expert with analyst firm Ovum said: "This is the first major disruption to the BlackBerry service since 2009, during which time the number of BlackBerry users has doubled."