because U9 is hot(it consumes big current) - it is damaged or some outputs are shortened to the ground, to another output or somewhere. if output is not shortened then chip u9 has been internally damaged and shortage is internal. also as i said - there must be resistors in serial from u9 to output jack.
ripple on graphs may have the reason, that u9 is shortened. device withstands high current, and this is the ripple with his generator frequency.
so. inspect where is shortage, with turned off device, anyway you cant have it turned on - u9 will burn down.
ps. do not try to drive speakers with device generator.
pss. nothing in this device could be hot. it is low current device, and all parts must be at (about) ambient temperature.