The overall ratings of three Computer and Personal Electronics stocks are down on Portfolio Grader this week. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Imation Corp. (NYSE:IMN) ratings are on the decline this week as the company earns a F (“strong sell”). Last week, it received a D (“sell”). Imation develops, manufactures, and markets a wide variety of products for removable data storage applications. The stock also earns F’s in Portfolio Grader’s specific subcategories of Earnings Momentum, Equity, Cash Flow, and Sales Growth. To get an in-depth look at IMN, get Portfolio Grader’s complete analysis of IMN stock

This week, Synaptics (NASDAQ:SYNA) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Synaptics is a worldwide developer and supplier of custom-designed user interface solutions for a variety of mobile computing, communications, entertainment and other electronic devices. The stock also gets an F in Earnings Revisions. The stock price has fallen 14.6% over the past month, worse than the 3.3% increase the Nasdaq has seen over the same period of time. As of Sept. 21, 2012, 22.3% of outstanding Synaptics shares were held short. For a full analysis of SYNA stock, visit Portfolio Grader

China Digital TV (NYSE:STV) is having a tough week. The company’s rating falls from a D to a F rating. China Digital TV provides conditional access (CA) systems to the digital television market in the People’s Republic of China. For more information, get Portfolio Grader’s complete analysis of STV stock

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here