Our Bose AV 321 series 2 has played same DVDs w/o problem for years and now suddenly when putting in the same DVDs all are coming up with the error "unsuported format". It still plays all the CDs we p

Hello Eugene

Here is your replacement remote.

https://www.google.com/search?q=bose+321+series+ii+replacement+remote

Amazon

Bose 321 Remote

Amazon.com https://www.amazon.com > bose-321-remote > k=bose...

Replacement Remote 289138001 Compatible for Bose 321 Series I Audio/Video AV Receiver [Work with Series I of Bose 321 ONLY] (Instruction Included). Infrared.

I wrote this Tip on remotes!

https://www.fixya.com/support/r29872378-universal_remotes_no_facsimile_remote

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Control buttons on the Media Center may need to be replace by a Bose service Technician.

The Bose 321 have an optical in port for external media.

BOSE offered a software upgrade to address the issue of freezing and not playing certain disks. You can get that right from BOSE by calling tech support. I am not sure that that will help with the newest symptom though (the humming).

If it's an original 321 system (series 1) then it has an audio output on the back. (via RCA jacks) You would still need an amp or receiver to connect the speakers to.. (unless they're powered speakers)
If it's a 321 series II or 321 series III- it does not have an audio output.
If the system has a DVD tray right in the middle of the media center, then it's a series 1.
Otherwise, you'd have to get a 1/8 splitter to come from your Mac's headphone output. (still- you will need an amp/receiver or powered speakers to have both 'rooms' playing the same thing from your computer)

lasers need changing expensive £200 or more

i have begun having a problem with my  4-5 year old bose 321 system.  sometimes dvd's burned on my computer will not  play on my bose 321 system.  sometimes they will.  what's up with this?  it's not a bad media problem.  i've narrowed it to the player.  sometimes i'll play a computer burned dvd on the bose and it will play fine.   next time i try to  play it it won't any ideas? thank you in advance mike

the bose will not play anew dvd comes up need paasword

Format unsupported simply means the unit can not read the disc. The problem is either the disc or the player.

Contact Bose technical support if you are sure the discs are good. 800-367-4008

maybe the DVD player you got is not supporting all DVDs from around the globe. There is this thing called NTSC region 1 for Americas, region 2 for Europe, Region 3 for Asia, Region 0 for everything. I don't know the other regions but that must have been the problem.