If you purchased a Proscan PLT9650G Tablet and are wondering why it is so slow, it’s because of a StressTest app that was probably left over from the manufacturer testing the tablet. It shows up as using 100% of the CPU. To speed up the tablet, this StressTest app must be force stopped and disabled. To force stop the app, go to settings, Apps, then scroll to All. Scroll down to StressTest for 5.0 and tap it. Then tap “FORCE STOP” to stop it. You’ll notice that the performance improves immediately, windows open faster, and the tablet becomes usable. However, to prevent the app from starting again it must be disabled. You’ll notice that the Disable button is greyed out.
In order to disable the app, you must do some developer tricks. There is a developer mode you can enable by tapping Settings, then About Device, then tapping on the Android Version seven times to enable developer mode. Once this mode is enabled, a new option will appear under System called “Developer Options”. Enable USB debugging under Developer Options, then use a micro USB cable to connect the tablet to your PC. Download ADB (the Android Debug Bridge) either as part of the Android SDK or here. This is a command-line Windows program.
Once you’ve installed the ADB program, unplug then replug the tablet into the PC and it will be recognized. Open a command prompt in Windows using Windows-R and enter “cmd”. Then go to the ADB shell by entering “adb shell” at the command prompt. You should see “shell@PLT9650G $”. If you see unable to find device (null), then your driver is not installed or your tablet became disconnected. You will have to allow your PC to debug the tablet, on the tablet, by tapping “Allow” on the tablet when you see a popup asking permission for your PC to debug the tablet. Once you are connected, enter “pm hide com.cghs.stresstest”. It will confirm that the app is hidden. (You may unhide it using pm unhide com.cghs.stresstest.) In the case of this version of Android (Lollipop) “hide” is the same as disabling the app, which is what we wanted to do in the first place. At this point, your tablet will perform better and the CPU-hogging StressTest app will no longer run automatically.
That’s all there is to it, and it’s just an example of time-to-market overriding basic provisioning common sense: you must remove debugging and stress-testing apps before shipping your product!
Charles Cavanaugh, Ph.D.