I am trying to use a USB stick in safe mode to update the system software on my ps3 to 3.50. im doing it this way because it will not update via internet without stopping and encountering error 80710723. i have tried turning off media etc etc. anyway when i have the USB plugged in the system says "No Applicable Data Found". why is this, i have tried 3 different USB sticks, all with nothing on them but the update i downloaded from the sony website. so why cant it read the info off of them? i am using a mac, does this effect it?

First, from your computer click the Download Link
to download the latest PS4 Update. Make sure you don't rename the downloaded file.
After download, plug your USB onto you Computer. Open the USB and make a folder inside named PS4 (you need to use Uppercase letters). Inside that folder create another folder named UPDATE. Then, just take the PS4UPDATE.PUP file you downloaded from the provided link and put it inside the UPDATE folder.
After that you just connect your USB with your PS4, and then from the Main Screen of your PS4 go to Settings -> System Software Update and just follow the instructions on-screen.
PS: Make sure you DO NOT turn off the console or remove the USB from the PS4 while the update is taking place, otherwise the system may be come temporarily or permanently damaged.

Download Link
http://dus01.ps4.update.playstation.net/update/ps4/image/2015_0625/sys_4f1c6d8597242ff346612773ffbc10ad/PS4UPDATE.PUP

I think that you may have a problem with either the system files or the HDD. Here are some steps to try before sending the PS3 Back in
First try:
1. Access safe mode with instructions from this link Safe Mode on PS3
2. From safe mode, click restore default settings.
3. If this doesn't work, go back to safe mode and click restore filesystem. If this doesn't work, go back and click the next option down. Stop at restore.
Second: (You will need some supplies)
1. Follow this until you get to the bold letters saying "Update Procedure"
PlayStation3 PC System Software Update Method PlayStation
2. Go back into safe mode and click "System Update"
3. Plug in your USB stick
IF ALL ELSE FAILS:
You need to replace the hard drive. Here are sony's official instructions:
Upgrade the Hard Disk Drive HDD
Make sure you use a PS3 compatible hard drive! (Listed in the above article)

Safe Mode is only for trouble shooting. You have bigger problems if you can't run normally. You may try installing XP on top of it's self.

this particular error is caused by corrupted data easiest way around this will be to install the update via a usb flash stick.

you can download the update here http://uk.playstation.com/ps3/support/system-software/detail/item541668/Update-features-%28ver-4-31%29/

this link will explain how to update via a Usb stick http://www.ps3news.com/forums/ps3-guides-tutorials/how-install-ps3-firmware-memory-stick-99095.html

Please only use the first to download the firmware only ever trust official sources.

1) Follow this link and download the latest FW update (3.15):

http://uk.playstation.com/ps3/support/system-software/detail/item249463/Update-features-%28ver-3-15%29/

2)Transfer the update on to a USB flash drive/pen to connect to the PS3. Stick it in.

3) Access the PS3 Recovery/Safe Mode. This will help to do so:

http://us.playstation.com/support/answer/index.htm?a_id=1488

4) Choose Option 6 - System Update. Should locate the FW file on the USB pen.

Put your PS3 into safe mode.
Put you finger on the on/off sensor an leave it there until your system turns off take your finger off the on/off sensor and then place it back on leave your finger their until you hear 2 consecutive beeps the remove your finger. This will put you into the system safe mode.

If you you have already done a system restore then start at try rebuilding the database, your system will restart after you do each of the safe mode options. You can also try downloading the 3.56 system software onto a usb via PC and doing a system update in safe mode.

Try accessing the recovery menu 'safe mode'.

Press and hold the power button until the systems shuts off. (wait 2 seconds)

Press and hold the power button again until you here 3 beeps. Let go.

It should ask you to connect your controller via usb and press the PS button in

the middle of your controller. There will be a menu with 6 options.You need 6.

You will need to have the latest firmware on a usb stick. Download the firmware from the playstation official website onto a usb stick. Once prompted by your system you will need to insert the usb stick into the PS3. Good luck..

If this doesn't work:

Your HARD DRIVE (aka: Hard Disk), located on the left side of the unit, has crashed. You will need to replace the HD.

When you replace your hard drive, you will need to have the latest firmware on a

usb stick. Download the firmware from the playstation official website onto a usb

stick. Once prompted by your system you will need to insert the usb stick into the

PS3. Good luck..

You will need 2.5" Sata Hard Drive.

Your HARD DRIVE (aka: Hard Disk), located on the left side of the unit, may have crashed. You will need to replace the HD.

When you replace your hard drive, you will need to have the latest firmware on a

usb stick. Download the firmware from the playstation official website onto a usb

stick. Once prompted by your system you will need to insert the usb stick into the

PS3. Good luck..

You will need 2.5" Sata Hard Drive.

Before you replace the hard drive, try:

Try accessing the recovery menu 'safe mode'.

Press and hold the power button until the systems shuts off. (wait 2 seconds)

Press and hold the power button again until you here 3 beeps. Let go.

It should ask you to connect your controller via usb and press the PS button in

the middle of your controller. There will be a menu with 6 options. Update using option 6.

Download the firmware from the playstation official website onto a usb

stick. Once prompted by your system you will need to insert the usb stick into the

PS3. Good luck..

Try updating your system the manual way:

recovery menu 'safe mode'.

Press and hold the power button until the systems shuts off. (wait 2 seconds)

Press and hold the power button again until you here 3 beeps. Let go.

It should ask you to connect your controller via usb and press the PS button in

the middle of your controller. There will be a menu with 6 options. Perform 6, "system update."

If this doesn't work, when your system froze and you powered it down, you may have corrupted your Hard Drive (Hard Disk). You will need to replace it.

When you replace your hard drive, you will need to have the latest firmware on a

usb stick. Download the firmware from the playstation official website onto a usb

stick. Once prompted by your system you will need to insert the usb stick into the

PS3. Good luck..

You will need 2.5" Sata Hard Drive.

Sometimes you want to put the remote in safe mode to recover from the LCD "blue screen of death" or other unsavory events. Usually you do this just before you update the remote's firmware (not software). So, you can try connecting to your computer via USB and, using the Logitech Software, go to Downloads-->Firmware. If you can get through the firmware update, you will probably be ok. Good luck