When I disconnet the sync cord and go to turn on the sansa e-250 it doesn't turn on

What you need to do is to format the device and try to transfer the songs..there could be an error with the device certificate...
Let me know if you need additional help

I have the same player, if my memory serves me correctly, you should be able to tell what firmware is on the device from the settings menu...

The description that says it holds 250 songs is an estimate - there are zero mp3 players on the market that actually hold the number of songs that the box/product sheet advertises. Those estimates are based on low-quality songs that are approximately 2 minutes in length each. So, it sounds very reasonable that 174 songs would fill the player's memory.

These are the most common methods for recovering Sandisk's Sansa Mp3 Players. I have been almost universally successful in recovering Sansa players using one or a combination of these methods. These methods do not work if you are having synchronization or music format issues - they are for recovering a player that will not power up, freezes, flashes, is not recognized by the computer, and a host of other issues.

Reset the Sansa Player first. On most models, restart is done by holding the power button in for 15 seconds or longer. Check your specific manual to be sure. The manuals are available from the Sansa website if they have been misplaced.
Download the Sansa Recovery Tool from the Sansa website.
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/DriverDownload/driverList.asp
If these fail, then:
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.
If you get the problem where MTP Device keeps popping up continuously, uninstall the “MTP Device” by going to Start à Control Panel àSystem à Hardware à Device Manager (you computer may vary slightly, depending on Windows Version).
You may have to restart your computer after each of these methods to get them to work properly. Disconnect your Sansa player BEFORE shutting down your computer.
-Tha Mp3 Doctor

Right click on your device and choose format, quick format. This can be found under My Computer, Removeable Devices

What version of windows are you using, did it install by itself without any troubles? It should show up in windows media player in sync or transfer to device.

These are the most common methods for recovering Sandisk's Sansa Mp3 Players. I have been almost universally successful in recovering Sansa players using one or a combination of these methods. These methods do not work if you are having synchronization or music format issues - they are for recovering a player that will not power up, freezes, flashes, is not recognized by the computer, and a host of other issues.

Reset the Sansa Player first. On most models, restart is done by holding the power button in for 15 seconds or longer. Check your specific manual to be sure. The manuals are available from the Sansa website if they have been misplaced.
Download the Sansa Recovery Tool from the Sansa website.
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/DriverDownload/driverList.asp
If these fail, then:
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.
If you get the problem where MTP Device keeps popping up continuously, uninstall the “MTP Device” by going to Start à Control Panel àSystem à Hardware à Device Manager (you computer may vary slightly, depending on Windows Version).
You may have to restart your computer after each of these methods to get them to work properly. Disconnect your Sansa player BEFORE shutting down your computer.
-Tha Mp3 Doctor

These are the most common methods for recovering Sandisk's Sansa Mp3 Players. I have been almost universally successful in recovering Sansa players using one or a combination of these methods. These methods do not work if you are having synchronization or music format issues - they are for recovering a player that will not power up, freezes, flashes, is not recognized by the computer, and a host of other issues.

Reset the Sansa Player first. On most models, restart is done by holding the power button in for 15 seconds or longer. Check your specific manual to be sure. The manuals are available from the Sansa website if they have been misplaced.
Download the Sansa Recovery Tool from the Sansa website.
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/DriverDownload/driverList.asp
If these fail, then:
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.
If you get the problem where MTP Device keeps popping up continuously, uninstall the “MTP Device” by going to Start à Control Panel àSystem à Hardware à Device Manager (you computer may vary slightly, depending on Windows Version).
You may have to restart your computer after each of these methods to get them to work properly. Disconnect your Sansa player BEFORE shutting down your computer.
-Tha Mp3 Doctor

Try this: disconnect the player from the computer, 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.
-----
Download the Sansa Recovery Tool from the Sansa website.
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
or
http://www.sandisk.com/DriverDownload/driverList.asp
-Tha Mp3 Doctor

Plug it into the computer (the cord you would use to charge it and transfer files), and hold down the power button for at least 15 seconds. The Sansa should then begin to turn on and start charging. :)

If it is still on, hold down the power button for about 15 seconds; that should turn it off. Try turning it on again. If it still does not work, turn it off by holding power for 15 seconds, then on again like this: - Put hold on - Hold record - Press power on This will start recovery mode, follow on-screen instructions. Hope all goes well!!