Will a 2004 am fm casette cd player part # A56821 fit into my 2006 toyota corolla S with same wire harness also?

Most CD/radio systems are built as a single unit so they will run on a single shared fuse. Is yours the original factory fitted unit? CD/Radio systems can wear out over time.
Some CD/radio units do use internal fuses. These are usually difficult and often expensive to replace. Fitting a whole new unit is usually cheaper and easier.

It sounds you have a short or an internal problem in radio I would by an after market radio with antenna kit and harness kit

all radios work if not OEM and bricked (code secret lost)
they sell an adaptor for your car that fits the stock harness, at
all autostores and even walfart.

buy that ,read the instructions, easy peasy city,

the phyiscal , i refuse to guess, only electronics.

Try suggestion 1, since resetting seems to be the only plausable idea. Otherwise, buy a new CD player. After market decks are usually better than factory ones, and you can get one that plays any file format from CD's or USB drives.

have you had any speakers or bass boosters installed in your car that werent in the vehicle before you purchased. Watch for wiring issues or possibly even battery voltage issues.

In here you can find information about Toyota 1999 Radio Replacement and here the Radio Wire Harnesess color codes.

I really hope help you woth this (remember rated this help) Good luck.

Good price and a direct fit. I have done several of these swaps. Nothing else needed

Try this: Remove the negative battery terminal for 5 minutes. Reconnect the battery termional and see if the CD player "resets" itself. This sometimes works for me.

your cd player track is misaligned youll need to replace it if you want a great deal on a new cd player or parts go to www.godspeedmotorsportsonline.comand click mobile I.C.E. tab

Your best bet on that one is to go to a place that sells car audio systems or even some autoparts retailers have them,and get the proper adapter harness already made up. A few more dollars but, a whole lot less headaches.