Where can I find a user manual for a Grtdhx 16GB MP3?

According to your manual, it has no lock. Try holding the UP Button as mentioned for other models.

https://www.google.com/search?q=agptek+a16stb+locked+out

Agptek A16STB Manuals ' ManualsLib

https://www.manualslib.com > ... > MP3 Player
Manuals and User Guides for AGPtek A16STB. We have 1 AGPtek A16STB manual available for free PDF download: User Manual ...

https://www.google.com/search?q=agptek+a16stb+locked+out

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Ematic has the User's Manual for several of their products on the product page. The Ematic E6 series MP3 player/video player are here: https://ematic.us/mp3-players/e6-series . Click on the Support tab. The direct link to the manual for these tablets is http://www.ematic.us/sites/default/files/E6%20Series%20User%20Manual.pdf . There is also the E6 Jr MP3 player/video player here: https://ematic.us/mp3-players/e6-jr-4gb-8gb-16gb . The manual for these is here: http://www.ematic.us/sites/default/files/E6%20User%20Manual1.pdf .

I hope this helps.

Cindy Wells

Hi Prabu
To answer what format does your player needS for video, it will be WMA.
For Pictures the format will be: JPEG, BMP
According to the user manual you will use "Songbird" to download videos to your player, the manual can be downloaded from this webpage: http://www.p4c.philips.com/cgi-bin/dcbint/cpindex.pl?slg=en&scy=us&ctn=SA4ARA16KF/37
User Manual Website: http://download.p4c.philips.com/files/s/sa4ara16kf_37/sa4ara16kf_37_dfu_aen.pdf
If you need to download "Songbird":

www. philips.com/Songbird or www.philips.com/support.

Bud

Please check and see if these links help:

www.mycreativefansite.com/2007/11/???creative-zen-4gb-8gb-16gb-pdf.html

www.creative.com/products/mp3

Hello

You can download the user manual for the device at the link below.

http://www.retrevo.com/support/Sandisk-View---16GB-MP3-Players-manual/id/23151dj983/t/2/

Kind regards
Andrea

personafile.com/Apple-iPod-nano-user-manual.html

you can get manuals at the follwing webpage http://support.apple.com/manuals/#ipod however I could not find the 1st generation manual but 2nd gen or others should help you out.

About your recent purchase of
16GB 4th Gen Slim MP3 MP4 Media Player with FM radio

You have been sold a fake sized player. it is hacked to show 16GB actual size may be around 1GB to 8GB. test your player with "H2TESTW 1.4" you will find it the first hit on www.google.com let other people know and open a dispute on paypal, you have been sold a fake item. Do not return the item for refund as sellers address is very likely wrong, useless to wait for a replacement player because they all are hacked. Get a partial refund. I paid 35usd, got 20usd refunded just now.

About your problem.
The player doesn't require anything works with vista and xp /etc just by plugging it into your computer and then turn it on, it will show up on your my computer as a removeable disk.

log on to thiw website, www.sandisk.com they should have what you need

Looking for a Users Manual for my new Sandisk Sansa View 16GB MP3 player