Almost every board that I have run into a locked on LED with known good CPU, PIA and ROMS and rom jumpers (and good ground traces to the PIA's) has been a bad chip at U15 which was a 3459 chip. This chip will test as a 7400 if you pull it and put it in a TTL tester, but you can't use a 7400 as a replacement. Suitable replacement is a 7437.

I did run into a board today on the job that has a locked on LED but booted fine in the game. replaced the LED and Q2 and now it shows the boot flashes.

As far as the reset section goes, if the only thing that is wrong with the game is the reset section then jumpering pins 39 to 40 will allow the board to boot. If jumpering those together does NOT allow the game to boot then there are other problems to fix first. So many people get hung up on this on these Bally boards and the Game Plan boards. The reset bypass allows you to immediately determine whether the REST OF the board is OK. When the game doesn't boot then fix WHATEVER ELSE is broken, then worry about the reset section later.

Other common issues I run into are bad traces running from U11 PIA to the U8 5101 RAM back up to the eproms. The amount of corrosion on that board almost guarantees that the 5101 socket should be replaced with machine pins so that you can solder the traces on the front and back of the board.

One other super common issue (which appears OK here) is the ground trace running to pin 1 of the two PIA from the bottom ground plain. I found a spot on the back of the board where you can connect the eprom ground lines to the PIA ground lines from (looking at the front of the board) the left side of C11/C81 to the top of C8/Pin 12 of U3. This reinforces/replaces the ground that gets lost from corrosion. Lots of boards booting again just from adding this.