4.88 is a problem. It must be 5V. Does your game have the recommended connector fix?

http://www.sternpinball.com/upload/downloads/sb106.pdf

You can buy the fix here:

http://www.pinballlife.com/index.php?p=product&id=1545

Also, you may want to change the connector on the DMD power supply board by unsoldering the old connector and soldering in a new one.

Other recommendations are to change the bridge rectifier BR1 on the power supply board and the bridge rectifiers attached to the backbox (there are three, I believe BR3 is the one pinrepair recommends).

http://techniek.flipperwinkel.nl/desega/index3.htm

If you do eventually buy a power board replacement, I highly recommend this board:

https://ksarcade.net/new-replacement-power-supply-520-5047-03.html

I recommend fixing any and all hacks. My Frankenstein hack on my power supply board was so bad, I just decided to replace the power supply board.

Hopefully your DMD display controller board is not hacked. Those can be pricey and difficult to find.

This was just posted a few days ago. A very good guide that covers everything you should try.

https://pinside.com/pinball/forum/topic/guide-to-dealing-with-large-dmd-games-with-resetting-displays#post-2623186

You may want to reconsider using that Xpin power supply in Sega Large DMD games. I went through two different revisions of that same board. Revision A gave me speaker noise. Revision D (which I was told would fix this issue) immediately locked my coils upon power up. This was in a Frankenstein. As I stated above, I used this power supply (which is actually modeled after the 520-5047-03 power supply boards only found in Sega Large DMD games):

https://ksarcade.net/new-replacement-power-supply-520-5047-03.html

My Frankenstein now works with no reset issues. Maybe Batman Forever will be okay, maybe I had a different underlying issue (not saying all Xpin power products are bad, I've used plenty in the past). Just posting my experience with that particular Xpin board.

Same experience. Brett was very generous with his time and it was much appreciated. Again, I have used plenty of Xpin products in the past. I just put a Green Xpin DMD in my Cirqus Voltaire. Really don't want my comments interpreted as an attack. Just wanted to relay my experience so you can look for the same issues if they arise.