Will upconversion work with my TW56X81?

I have a fairly decent system (for 2000).

Toshiba TW56X81 "HD Ready" RPTV (16:9)

Toshiba SD5109 Progressive Scan DVD Player

Marantz SR5500 A/V Receiver


Since two days ago, I get no sound over the optical link from the DVD Player to the A/V Receiver. If I switch to the RCA analog jacks, I have sound.


Assuming that the DVD Player is no longer putting out an optical signal, I'm thinking I should get a new player. (If it turns out to be the receiver's input of the optical signal, then I will have to re-evaluate.)


I'm not quite ready to upgrade to an HDTV but the TW56X81 is supposed to be "HD Ready". It does not have an HDMI input. Will a DVD player that upconverts over its component outputs (and not just over HDMI), can the TW56X81 ("HD Ready") do anything with the signal? I have read the TV manual and cannot figure out whether an upconverted signal from the DVD player will do any good on this TV.


My other option is just to buy a really cheap progressive scan DVD player to use until I buy a new TV -- then upgrade the player as well.


Any thoughts?