tech: rock-ola 478 won't select

Looking for any info that may help. I have a rock-ola 478, machine
powers on, basket cycles one time stops at rest position. L.e.d. on
Profit Setter indicates power there, hit tracker is working, and the
top 3 song displays work. I have no display for credit or record
playing etc. The machine will not credit via coin switches or free
credit button. I have changed the IC on the Profit Settter with one
from the Hit Tracker as suggested in another post here, but nothing
different, no displays. If I run the mech test (push test button on
front mech board) it completes the test just fine.
Thanks for your time,
Paul

Paul,
First off, make sure you have the dip switches properly configured. Then, if the Profit Setter has the "anti-static" boards piggy-backed onto the main PCB, remove them. Reconnect all the connectors directly to the Profit Setter and test. Next, there is an elaborate test procedure for the Profit Setter that can be performed if you have the information. If not, I can provide it, but will have to scan it first. If it's not working after all this, you will need to dismount the Profit Setter and check the connectors for cold solder joints. If still no luck, set the Profit Setter for "free play" by turning off all dip switches on bank "D" and cycling the power to the machine. See if you can make a selection and have it play. If it does, your probably looking at failed displays or cabling. If it doesn't your Profit Setter just became a "profit setback. Let me know what you find and if you need more information.