Q: To free up storage space on my Android smartphone, I often go to the photo gallery and delete some pictures. But I can't seem to delete the 203 photos that were synced to my phone from Google's Picasa online photo app. How can I get rid of these photos?

John Knoderer, Manning, S.C.

A: The Picasa photos were automatically downloaded to your phone from Google Photos, the online successor of the Picasa app that Google discontinued last year. You can get rid of the photos by changing a few phone settings.

What's causing this problem? The default setting for your Android smartphone is to sync to the phone any pictures you have stored online in Google Photos. If you turn off this auto-sync feature, your phone won't receive any more of those pictures.

To turn off photo auto-sync, open your phone's "settings" app, and under "personal" choose "accounts," then "Google." You will be given a choice to turn off syncing for specific apps; disable sync for "Google Photos" and, if present, "Picasa Web Albums."

Now you can delete the unwanted photos from your phone; note that copies of the deleted pictures will still exist online in Google Photos. To do that, go to "settings" again and choose "application manager" (on some Android phones, you must instead choose "application," then select either "manage" or "manage applications.") Choose the tab for "all," find the photo gallery app in the list and click it. Then click "clear data." The next time you open the photo gallery app, the unwanted photos should be gone.

Q: I got my 2010 HP desktop PC out of storage, but discovered that it will no longer work with the same monitor it always used. I get an error message that says "No VGA signal." The same monitor works fine with my laptop PC. What's wrong?

Barry Clark, Morgan City, La.

A: If the monitor works with your laptop PC, then the problem lies with the HP desktop. "No VGA signal" means that the PC isn't getting a signal from the VGA, or "video graphics array," port where you plug in the monitor. That likely means the video circuit board connected to that port is loose or has quit working.

You can try to adjust the board in its socket by removing the PC's case. (First, ground yourself by touching a metal object; otherwise the static electricity on your body can damage the PC's components.) Locate the circuit board attached to the VGA port and remove it from the connector that links it to the PC's main circuit board. Then firmly plug in the circuit board again. If this works, your monitor will function with the desktop PC. If not, you will need to buy a new video circuit board.

Readers Karen Scheltema of Minnetonka and Gordon Hostetler of Elkhart, Ind., thought I left out an important point when I explained how to prevent a laptop mouse cursor from skipping around the screen (see tinyurl.com/y8xmsabg). They correctly noted that cursor-skipping can be caused by a PC user's hand coming too close to the laptop's overly sensitive touch pad. The solution is to disable the touch pad (see tinyurl.com/hz2xksx) while using a mouse.

E-mail tech questions to steve.j.alexander@gmail.com. Include name, city and telephone number.