That "burnt chemical smell" is a very unique smell and it's always bad news, unfortunately. I would not risk your connected speakers/equipment again, nor risk a fire in your house. UNPLUG that receiver and leave it unplugged.

If you can get a free or $20 quote locally (not pay for shipping) than do it, but I'm betting it's not worth fixing.

Are you just looking for a 2-channel amp or a HT 5.1/7.1 receiver/AVR?