I have a gpx-mw3837red 1gb that won't play!

its frozen

Here is a link to the official GPX ML638b page http://www.gpx.com/store/p/261-ML638B.aspx I think the link to Software Restore Utility has the drivers you need. (I'm not 100% sure)
The only difference between the ML648B and Your model is that yours holds 1GB and the other holds 2. Also the Letter at the end of the models name specifies which color it is, B for Black and S for Silver.
Movies must be an AMV file format see here for a full tutorial on that http://www.fixya.com/support/r2808906-videos_pictures_gpx The link has a video tutorial on what you must do step by step to begin enjoying videos.

As far as only playing the first couple of seconds of music, your player may be in Intro Mode. To remedy this, Play a song and hit the button on the side of the player, select Play Mode and then select Normal.

I hope this answers all of your questions and gives you a better understanding of this device.

This need arepair as the controller board is giving out there is not much we can do here but send you to a GPX autherized repair to have it fixed but these things beeing so cheap now days I would just go to best buy and they will recycle this old one give you a gift cart for whatever amount they think its worth toward a new one..

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/edwy_1a56970cf1ea4620

it might be song format problems
check

Corrupt DB - double check GPX's website for firmware update
If no, then reformat player:
There are two ways to format an Mp3 player - one on the computer itself, and one in Windows Media Player. Both methods will end up erasing all the songs on the player, but the player will be "good as new" after that. Sometimes reformatting in this manner will override the player's native formatting and cause problems - this can be reversed in most cases by updating the player's firmware. Firmware upgrades are available from most manufacturers' websites.

WARNING: The following procedures will erase all songs on the player.

Check if the file system is NTFS. If yes, format it to FAT or FAT32. - Connect player to computer, double-click my computer, right click on icon of mp3 player and select format. This only applies to Windows-based computers.
You can also format the player in Windows Media Player itself:
Connect your Mp3 player to the computer and open Windows Media Player. Click on the Sync tab. Pull down the drop down menu underneath the Sync tab by moving your cursor over the Sync tab and left clicking on the little black arrow underneath the Sync tab. Highlight "name of Mp3 player here 1GB" (wording may vary slightly), and then select "Format." - this should erase everything.
-Tha Mp3 Doctor

You switched to MTP mode possibly - reverse it

Probably screwed

Last ditch effort:

Try this: disconnect the player from the computer, turn it off, hold in the volume + button, and reconnect the player to the computer while holding the volume + button in. Keep holding the volume + button for an additional 5-50 seconds. Windows should eventually go into recovery mode and revive the player- it will pop up a window that says Found New Hardware Wizard

hello!

all you need is to connect the stuff to the computer, the computer will detect drive from your stuff. in there, you can browse and delete files in it.

fixya,

best regards, melnavz

The song could have drm encryption or it could be in the wrong format.

Go ahead and do this, in case the DB is corrupted:
Format - Erases Everything: Connect your Sansa player to the computer and open Windows Media Player. Click on the Sync tab. Pull down the drop down menu underneath the Sync tab by moving your cursor over the Sync tab and left clicking on the little black arrow underneath the Sync tab. Highlight "Sansa 1GB" (wording may vary slightly), and then select "Format." - this should erase everything.
Firmware Upgrade- Erases Everything: Get the latest firmware upgrade from Sansa - it updates the firmware and erases every song in the player all at once. Note: this method doesn't work if already have the latest firmware. Go to this website and click "Firmware Updater" to find out: http://www.sandisk.com/Retail/DriverDownloads.aspx

If you get the MTP on your screen and your trying to sync it with your computer just press and hold the usb/mtp button and your computer will reconize it [=