working on a1990 that was working but had failed usb port, replaced the bad cd3215 (ub300) but had no power after, replaced ub400 still no power, chips i was using were bought online, figured maybe the was bad, so i pulled chips from donor board and reballed,
anyhow after spending most of the day Sunday on it i have restored 5v to all ports with .45amps, but UB400 i getting hot, both ub400 and ub300 have been replaced 4-5x cant seem to figure this out, cant seem to locate short on any of the LDO lines or surrounding components, qb300/qb4000 u7000 and rom chip have also been replaced
anyhow after spending most of the day Sunday on it i have restored 5v to all ports with .45amps, but UB400 i getting hot, both ub400 and ub300 have been replaced 4-5x cant seem to figure this out, cant seem to locate short on any of the LDO lines or surrounding components, qb300/qb4000 u7000 and rom chip have also been replaced