I have an intermittent boot problem on Nascar that sometimes requires pushing the reset button on the CPU after startup to get it to boot. This was a sample game that was delivered to a friend of mine with no CPU board, so a reman from Stern was sent to him, and the I purchased it from him shortly thereafter. It did this when I picked up the game,and many times thereafter, but now I want it fixed.
When the game is turned on L200 will not be lit and L204 on the I/O board will be blinking, and the playfield lights will be flashing. Push the reset button and the game boots right up. I have isolated the problem to the CPU board by installing a known good I/O board and also checking the 5v and the 3.3 volt at startup. They both come right up.I have also disconnected all other power circuits to verify it is not a short elsewhere.
After pulling out my hair for several months, I hired one of the best techs available to troubleshoot this for me. He rebuilt the 5v on the I/O board and replaced the PAL chip and the U413 watchdog, and tried a few other things, but to no avail.
The board looks good with no acid damage and no hacks, and all the solders look good. I am about to give up and order a new board, but I am hoping that maybe one of you has seen this issue before, and can direct me to the component that may be causing this problem. If I have to spend much more without fixing the problem, I may as well get a new board. Thank You.