Dell

(DELL) - Get Report

was among technology's losers on Friday, tumbling 6% on heavy volume after the company posted bleak earnings and revealed the

Securities and Exchange Commission

is investigating its accounting practices.

The PC maker said in its earnings report late Thursday that it "has discovered information that raises potential issues relating to certain periods prior to fiscal 2006" in the course of responding to SEC requests for information relating to revenue recognition and other accounting matters. Dell said it doesn't believe that these issues will have a material effect on its financial position. The company's audit committee has launched an independent investigation.

For the second quarter, Dell's sales totaled $14.1 billion, while earnings were 22 cents a share, in line with analyst expectations. A year earlier, Dell recorded EPS of 41 cents on sales of $13.4 billion. Shares were trading down $1.26 to $21.54 on volume of 58 million shares, more than twice its daily average.

Dell also announced that it would begin selling desktop PCs using

Advanced Micro Devices

(AMD) - Get Report

chips next month, and expand its array of corporate servers with AMD chips. Shares of AMD lost 1.8% to $23.76 on Friday. The stock jumped earlier in the week in anticipation of the Dell deal, and after an upgrade by Citigroup.

Marvell Technology

(MRVL) - Get Report

plunged after it posted partial, and disappointing, second-quarter results.

For the quarter ended July 29, Marvell reported sales of $574 million, up from $390.5 million a year ago. Still, the figure was below Thomson First Call's average analyst estimate of $583 million, as well as the company's own guidance of $580 million to $585 million.

As expected, Marvell didn't provide its earnings numbers due to an ongoing stock options probe by the

SEC

and a federal grand jury.

For the third quarter, Marvell forecast sales of $580 million, falling far short of Wall Street's estimate of $622.5 million. For the full year, Marvell reduced its revenue projections to between $2.27 billion and $2.29 billion. In May, the company's projected full-year sales between $2.37 billion and $2.425 billion. Analysts were looking for revenue of $2.4 billion. Marvell shares were off 8.6%, subtracting $1.77 to $18.71 in recent trading.

Wireless chipmaker

Atheros Communications

(ATHR)

ended the week on a sour note, with the stock 7.8% lower. Earlier this week, the company completed its acquisition of

Zydas Technology

, a Taiwan-based company specializing in wireless LAN semiconductor and software for PC, mobile and embedded applications. Terms of the deal were not disclosed. Atheros recently was down $1.41 to $16.75.

Meanwhile, shares of

TiVo

(TIVO) - Get Report

jumped on news that it had prevailed in a patent fight with

EchoStar Communications

(DISH) - Get Report

.

A federal judge ruled to halt sales of certain EchoStar digital-video recorders and slapped the satellite broadcaster with $89.6 million in damages. TiVo sued EchoStar in January 2004, alleging that EchoStar boxes infringed TiVo's time shift patent covering simultaneous playback and recording.

EchoStar vowed to appeal, though TiVo said an EchoStar motion to have the verdict stayed pending appeal was denied.

Tivo shares popped 8%, adding 53 cents to $7.02. EchoStar fell 2.1%, or 70 cents, to $32.05.

Microsoft

(MSFT) - Get Report

also moved up after boosting its stock buyback plan by $16.2 billion. Shares recently tacked on 77 cents, or 3.1%, to $25.47.The Redmond, Wash., software behemoth adjusted its buyback plans after a $20 billion Dutch auction self-tender fell short of expectations.

Other tech movers on Friday included

Intel

(INTC) - Get Report

, off 15 cents to $18.41;

Sun Microsystems

(SUNW) - Get Report

, down by a dime to $4.62;

Cisco Systems

(CSCO) - Get Report

, down 20 cents to $20.65;

Oracle

(ORCL) - Get Report

, off 13 cents to $15.68;

Sirius Satellite Radio

(SIRI) - Get Report

, adding 9 cents to $3.84;

JDS Uniphase

(JDSU)

, off 4 cents to $2.42;

Broadcom

(BRCM)

, down 55 cents to $29.50;

Apple Computer

(AAPL) - Get Report

adding 38 cents to $67.97;

Brocade Communications Systems

(BRCD)

up 15 cents to $5.56;

eBay

(EBAY) - Get Report

, down 52 cents to $27.15 and

Applied Materials

(AMAT) - Get Report

, off 15 cents to $15.66.