Action Pinball Logo Technical Articles

Order by phone or online: www.actionpinball.com  
 
Salt Lake City, Utah, USA
E-Mail: info@actionpinball.com
Search:    Search Tips...   
Quick Links:
- Home Page
- Game Parts & Supplies
- Game Service & Repair
- Pinball Machines for Sale
- Video Games for Sale
- Ordering Info
- Contact Us

ROM Chip Installation
The following information applies in general to most makes and models of pinball machines and is intended as a guide, or "how-to", on how to remove and replace ROM chips, or otherwise update the software, in these games. The information given below may not be exactly specific to your make/model of pinball machine, so should be taken only as a general guide to ROM chip replacement or software updating, rather than specific instructions for your exact game.

NOTE and DISCLAIMER: Read the instructions below before attempting any of the work. If you are uncomfortable performing any of the steps below, contact us, or return chip(s) for a refund (less labor, shipping, and handling costs). Chip(s) must be removed/installed properly to ensure proper operation. We are not responsible for any damage to the chip, you, your game, your location, or any problems or inoperability of your game due to problems with you removing and/or installing chips in your game.

Location of ROM Chips in Your Game:

Most replacement chips we sell include a diagram to show where different ROM chips are located in your particular game. You can also find some of this info on our website in our ROM Chips Page. If you have any specific questions, feel free to e-mail us.

Page Contents:


General ROM Chip Removal and Installation Instructions:

Preparation:

Before changing ROM chip(s) in your game, do the following steps:
  1. Make a record of any custom settings, audits, adjustments, and/or high scores you may want to save from your game before you replace ROM chip(s). Replacing ROM chips will usually reset all information back to factory "default" values, so this information will likely be lost, and have to be re-set, after replacing ROM chips.

  2. Turn power off. Always remove and replace chips ONLY WITH POWER OFF!

  3. Open game to gain access to the circuit boards where you will be replacing chips.
(Click any image below for larger view.)


Late-Model Sega/Stern Pinball Game ROM Location


Bally/Williams WPC Game ROM Location


Late-Model Sega/Stern Pinball Display ROM Location
Step 1:

Locate the chip you will be changing. Location of chip will vary depending on the game, manufacturer, age, etc. A few common examples are shown to the left.

If you are unsure about the location of the chip you are replacing, check the information written on the label on the chip (if present), consult your game operation manual, or contact us.

Chip Indent
Step 2:

Locate the indent on the chip that is in your game. The indent is a semi-circle, or "half-moon" mark, and is always on one end of the chip. This indent matches up with a similar indent on the socket that the chip plugs into.

Depending on the location and orientation of the chip in your particular game, the indent will be facing in the direction of up, down, left, or right.

Make note of this- the replacement chip will have to be installed in the SAME direction as the existing chip, otherwise it could be damaged, in which case you'd have to buy another one.

Do not go by the direction of the writing or label on the chip- always locate the indent on one end of the chip, and install in the same direction as the indent on the chip socket. This step is most important.
(Click to Enlarge)




Step 3:

Remove the existing chip. To do this, use a chip extractor tool, or a small flat-blade screwdriver, or thin/flat pocket-knife blade.

Insert tool carefully under ends of the chip and gently start to pry upward to extract the chip legs from the chip socket.

NOTE: The tool must go between the chip and the chip socket. Be careful not to put the tool underneath the chip socket (between chip socket and board), otherwise you could damage the socket, the PC board, and the chip, if the socket is accidentally pried off the board.

If using a chip extractor tool, gently rock the tool & chip back/forth to ease it out of the socket.

If using a flat-blade tool, continue to work the tool in underneath the chip, gently prying upward as you go. Work from both ends of the chip if possible, to avoid bending the chip legs.

The idea is to try to pry the chip straight up and out of the socket, rather than bending it back as it comes out. Bending the chip back can crack and possibly break the chip legs, rendering it useless (we cannot take chips on exchange that have had bent legs- this causes them to crack due to metal fatigue, which leads to premature failure of the chip). These are very delicate parts and must be handled as such.

Once the chip is nearly free of the socket, grasp it with your fingers and gently work it the rest of the way out of the socket. Be sure not to bend the chip backwards and/or damage any chip legs. Patience and caution are required for this step.
(Click to Enlarge)




Step 4:

Install the replacement chip. The easiest way to successfully install a chip into a chip socket is to first line up one side of the chip legs with one side of the chip socket. Don't press the chip legs down into the socket yet- just allow them to rest lined-up on the one side of the chip socket.

While keeping one side of the chip legs in one side of the socket, gently "roll" the chip over to line up the other legs with the other side of the chip socket. You may need to gently press the chip back toward the other side of the socket in order to get the legs on the second side to line up just right with the chip socket.

Use caution in this step in order to avoid bending or mashing any chip legs with your fingers. All chip legs should line up with their respective positions on the chip socket before you press down to seat the chip in the socket.

Gently press down on the chip to push and seat it into the socket. This may actually require a bit of force to ensure that the chip is fully seated.

Watch carefully before, and as you seat the chip into the socket, to make sure all chip legs are IN the socket and that none are hanging outside the socket, or bent underneath the chip (stuck between chip and socket). If any legs do not go straight into the socket, then the game will not function and you could risk damage to the game, and the chip, in which case you may have to buy another chip.

This step is very important, and requires patience and caution. Double check your work after seating the chip to make sure it is fully seated, and that no chip legs are bent, hanging out of the socket, or bent/rolled underneath the chip (stuck between chip and socket).
Step 5:

Double-check both sides of the chip to make sure all legs are properly seated in the chip socket.

Double-check the surrounding area to make sure you have not bumped or pulled any connectors or cables loose from the board you are working on, or any boards nearby. This is the most common cause of failure that we hear about when removing/replacing chips on circuit boards. If your game does not start up after you've replaced the chip, proper installation of the chip in the socket, and secure cable connectors are the first things to check.

Once you have double-checked your work, power up the game, and verify that it boots up properly.

If you have replaced a CPU (game) ROM chip, your game's audits, settings, adjustments, and high scores may get reset to factory "default" values, and you may have to be re-set some settings (such as "free play", number of balls per game, etc.)

Your game may display an "error" message, depending on the make/model. Here are some examples:
  • Bally/Williams Games (~1986 - 1999): These games may display "Adjust Failure", "Factory Setting", or "Factory Settings Restored" after replacing a game ROM chip. If so, turn game off, then back on, and the message should clear, and the game should boot up into attract mode- waiting to be played.

  • Capcom Games: These games may produce a "Volatile RAM Error" or similar message after replacing ROM chips. Simply power-off, then back on, and the message should clear, and game should boot up into attract mode- waiting to be played.

  • Williams Solid-State Games (1977-1985): These games may boot up into "audits" mode after having ROM chips replaced. If so, power-off, then back on, and game should boot up in to attract mode- waiting to be played. If not, be sure that the coin door is open when you power-off and back on. This allows the interlock switch inside the coin door frame to open, which lets the CPU board clear it's memory and reset. If coin door is closed, it can't do this, and will stay in audits mode every time you boot up.
Some games will not produce any messages or give any indication that ROM chips have been changed, when powering-up after replacing ROM chips. These include early Bally and Stern solid-state games (1977-1985), Data East games, Sega games, late-model Stern Pinball games, and possible others.

If you encounter any problems, double-check your work. Make sure that the legs on any chips you installed are fully seated in the chip socket, and that none are hanging out of the socket, or curved-in under the chip (between the chip and socket). Also make sure that all cables/connectors on and around the area where you were working are still firmly connected to the board, and that none have been bumped loose, or left uninstalled if any had to be removed to gain access to the ROM chip. (Loose cables are the number 1 problem we see that is associated with ROM chip replacement.)

You can also see the section below on Related Articles for additional information.

Notes/Details: Bally & Stern Solid-State Games (1977-1985) ROM Chip Replacement:

Read the
top section first, regarding basic ROM chip removal and installation.

The factory-original MPU boards in Bally and Stern solid-state games (1977-1985) were designed to use several different types of ROM/PROM/EPROM chips, and can be configured for specific types of chips by setting "jumpers" on the board.

"Jumpers" are basically small wires that connect two points on the board. (Click here to read about jumpers as used on late-model Bally/Williams games.)

Stern Boards:
You should always check your board first to see how it is set up, but jumpers usually do not have to be changed for later Stern MPU-200 boards, as most of these were set up for EPROM chips at the factory, and should be "plug-and-play" ready for new replacement EPROM chips. Earlier MPU-100 boards will have to be modified, and have jumpers set properly for 2732 EPROM replacement chips in locations U2 and U6. In either case, you should always check the current setup of jumpers on your board first to make sure it is configured properly for the chips you are installing. (Click here for early MPU-100 jumper info. Click here for later MPU-200 jumper info). On an original board, it's always very possible that changes could have been made sometime over the board's 30+ year history...

Bally Boards:
Jumpers will need to be set for 2732 EPROM chips in locations U2 and U6. Early AS-2518-17 boards will have to have additional modifications done as well. You should always check the current setup of jumpers on your board first to make sure it is configured properly for the chips you are installing. (Click here for early AS-2518-17 jumper info. Click here for later AS-2518-35/-133 jumper info).

For example, most Bally games will use 2 replacement 2732 EPROM chips in locations U2 and U6. So the board must have jumpers "set" for 2732 ROM (or "EPROM") chips in locations U2 and U6.

Bally used three different MPU boards between 1977-1985, and Stern used two different MPU boards. The type of board is denoted by the part number printed in the lower right-hand corner of the board:
  • Bally MPU Boards: AS-2518-17 (early), AS-2518-35 (late), AS-2518-133 (late- used in Baby Pac-Man and Granny & The Gators only).
  • Stern MPU Boards: MPU-100 (early), MPU-200 (late).
All will require specific jumper settings for the type of board, and types of chips being installed. Early boards (AS-2518-17 and MPU-100) will also require some modifications to be made to the board.

If you are not sure what kinds of ROM chips your board is set up for, or if you need to know which jumpers to set on your board, please see the following articles on our site: If you are not comfortable changing jumpers on your MPU board, you can enlist the help of a qualified/experienced helper. Even a local TV/VCR repair shop can do the work for you with the information from any of the above articles on our website.

If you have any concerns or questions, feel free to e-mail us.

Data East, Sega, and Stern Pinball Display ROM Replacement:

Read the
top section first, regarding basic ROM chip removal and installation.

Some late-model Data East, all Sega, and all new Stern Pinball games have a separate ROM chip for the display unit. This display ROM chip is located on the back side of the display unit itself (which is mounted to the speaker/display panel).

To replace this chip, you will first need to remove the speaker/display panel.

(Click any image below for larger view.)

Step 1:

Remove backbox translite (backglass) assembly and set it aside to gain access to the speaker/display panel.

This panel may be secured in place by two screws at either top end- check for these before trying to remove the panel. This was usually done in Data East games- screws and gray plastic spacers were used. Remove these before attempting to remove the panel.

Grasp panel with one or both hands and lift straight upward. Panel should come up about an inch.
Step 2:

Pull top of panel outward from backbox.
Step 3:

Lay panel down on playfield glass surface. This will allow you access to the back of the display unit. You should then be able to locate the ROM chip.

  • Click here to see the instructions above for removal and installation of the ROM chip.
  • Click here for information on changing two display ROM chips for one ROM chip (and vice-versa). This is required on some Data East and early Sega games (not all).
Additional Notes/Details:
  • Data East "Short" Display ROM Chips:
    Some replacement display ROM chips may be shorter than the chip you are replacing, or shorter than the chip socket that the chip goes in. If you ordered your chip from us, you should have received a small paper with the chip showing the correct installation of the ROM chip for this configuration. It will look like this:

    The short chip can be installed in the long socket by lining up the back end of the chip, with the back end of the socket. The back end is the end that DOES NOT HAVE AN INDENT. When properly installed, any unused (empty) positions in the chip socket will be at the front (indent) end of the chip and the socket. See the top section on this page for information on chip indents.

  • Data East & Sega Display ROM Jumpers:
    Some Data East and Sega games may require a jumper change when replacing 2 display ROM chips with 1 single chip (or vice-versa). See our article on this for proper installation and jumper settings.



Late-Model Stern "SAM" System USB Key Software Updating:

Instructions not currently available here, but step-by-step instructions are included with
USB key updates that we supply. These can be ordered on our ROM Chips Page.


Jersey Jack Pinball USB Key Software Updating:

Instructions not currently available here, but step-by-step instructions are included with
USB key updates that we supply. These can be ordered on our ROM Chips Page.


Related Articles:


Back to Top

Back to Home Page