Jurassic Park
Data East, 1993You're currently viewing posts by Pinsider johnjn.
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Hi All,
I'm attempting to troubleshoot an issue with the DMD display on my JP -- throughout play it seems to display certain lines as active that shouldn't be. It doesn't affect gameplay but visually doesn't look nice.
Is this a common issue? any suggestions for fix?
The roms in the game are quite old (Display V4.00 / CPU 4.04) and will be installing v6 roms very shortly.
Screen Shot 2019-04-07 at 2.34.50 PM (resized).pngFound this:
https://pinside.com/pinball/forum/topic/tron-dmd-display-problem-with-extra-line
Perhaps its time to try a new DMD.
Quoted from PinballManiac40:Your JP has a plasma display. The Tron has a LED display, which is a different design. I don't think this is a DMD issue in your game. Looks more like a RAM problem, but not sure if the DMD controller has one there.
Thanks @pinballmaniac40 - I will research further.
Quoted from kbliznick:If it's only a partial line I'd also go with a RAM problem. Try swapping the DMD to a different game to verify it's not on the DMD board but an issue with the RAM on the DMD driver board.
kbliznick -- sadly this is my one and only pin, I'm new to the hobby so I'm not able to swap DMD's into another machine just yet.
Quoted from PinballManiac40:Found it. It is on the DMD controller board at U8 location. Likely it is soldered in, not in an IC socket. The manual shows it as a 62256 RAM, but need to check the actual part to make sure.
PinballManiac40 -- Thanks, I will open up the game and check it -- But I've googled '62256 RAM' but only NVRAM seems to come up on Marcospecialties -- would this chip work for a DMD controller board?
Quoted from PinballManiac40:It may but would be overkill since the regular RAM would likely be $10 cheaper. I will try and look on the internet tomorrow.
Other manufacturers used 6264 RAM, but not sure if it could with a jumper change, on this board, assuming one exists.
I found ones listed on eBay, but it seemed like variations with different end lettering to the ram designation.
Quoted from PinballManiac40:You have to watch if these come from China. You don't want a counterfeit part. You will definitely want to use an IC socket once the old one is out.
Hmm - that sounds like a great plan, however completely out of my skill set unfortunately -- I've never soldered anything before let a lot reset a socket unfortunately.
Quoted from PinballManiac40:No problem. Chrishibler will be happy to help.
Damn man - I think I owe you at least a round or two, thanks for all the help!
Quoted from PinballManiac40:Here is something you can do. This is plug and play (for all DE, Sega and Stern Whitestar games) and no soldering required for your JP game. NVRAM will eliminate batteries out of your game.
https://www.pinitech.com/products/6264_nvram.php
Ordered! Thanks man!
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