Does the display driver board have the display roms installed? You mentioned that you were missing rom chips... do you now have a full set? There are roms for program, audio and dots. The DMD rom is located on the DMD controller board. If I recall correctly, a bad rom will result in garbage on the DMD screen. It wouldn't prevent bootup however...

Hows your +5v looking? All the PCB's need 5v to boot up properly, including the display controller. If I had to guess, your 5v power train is dead (probably bad connectors, those DE power supplys get HOT).

Post a picture of the "cube connector" (you can see the edge of it in your picture). If that connector is even remotely discolored, both the headder and connector should probably be replaced.

To properly diagnose your issue, you're going to need a multimeter and you're going to need to probe all of the test points on the Power Supply as well as the CPU board (there are marked test points for GND and 5v/12v). Make sure all of your values are within range.

If I had to take a blind guess, you have bad connectors on the power train. All three Data East machines I've owned had that same problem.

If your connectors look like the ones pictured below (CN1 and CN8), they more than likely are bad

DEPowerSupply.jpg

And, in this pic, in the upper left corner, you'll see two "metal loops" marked GND and +5v. Put your black multimeter lead on GND and red lead on +5v. Put your multimeter in autorange DC voltage and ensure you're somewhere within 4.9v-5.2v.

If 5v is missing, the game will not boot.

De_cpu_520-5003-04.JPG

Another thing I forgot to mention- check how "springy" the fuse holders are. Data East boards are known to have flaky fuse holders. If they do not grab the fuse VERY tight they need to be replaced.

Yeah- that header looks a bit questionable to me. I would suspect the mating connector is also discolored?

Yes, it is absolutely salvagable. There are a number of tech's (myself included) that can help you change that connector out. If you're not comfortable soldering it, or would prefer peace of mind getting a brand new board, that option is there as well. I had a power supply that was too far gone to repair and opted for a Rottondog replacement. Worked out great!

Before you consider repair or replacement however, do check your current voltage readings as discussed above! We're looking for +5v on the CPU. The status LED's should help you quickly determine if its working and or working properly. See the link below for the LED flash sequence:

http://www.pinwiki.com/wiki/index.php?title=Data_East/Sega#Data_East_CPU_Board_LED_Flash_Sequence

No LED's = no power. Even if you do not see the LED's flash, measure the test points I described above. Its possible you have 5v exiting the power supply, but something (connectors, bad IC, etc) are dropping the voltage out of range.

Wait- so there is +5v on both the PSU and the CPU?

If you're seeing solid +5v on both, its not a connector problem. If you're seeing it ONLY on the PSU and NOT on the CPU, its a connector issue.

Are you 100% certain your roms are installed the correct direction? The notch silk-screened on the CPU should match the notch on the eprom. Also, do any of the chips get hot to the touch?