This means that the MPU is not "locked" - it is working, but up to a certain point.

What you should see is a brief "flicker" and then seven flashes.

First Flicker = CPU, PIA (U11) and ROM (U6) can be read = good sign

First "flash" = All ROMs are good

Second Flash = RAM (U7) is good

Third Flash = RAM (U8) - 5101 is good

Funny thing is - you mention it is going into "attract mode" - Sounds like U8 (5101) is not good - which is quite comon. This is also a chip that is prone to static. You can cover your bases by re inserting U7 + U8. Be VERY careful with U8 - try not to touch the legs or wear an anti static strap.