Konami Bubble System

The Konami Bubble System (Also known as the Konami GX400) is a 16-bit arcade machine platform produced by Konami in the 80s. Unlike it's contemporaries, the Bubble System utilized bubble memory technology in favor of floppies, silicon-based ROMs, or hard disk storage. The system is known for it's boot screen and music ("Konami Morning Music") as well as the original platform for iconic video game franchises such as Gradius and Twinbee.The system was a commercial failure for being more expensive than existing ROM-based systems and the obsolescence bubble memory chips.

Known Issues
The Konami Bubble System is known for being particularly fragile and highly sensitive to electromagnetic interference. If the system is subject to strong magnetic interference (ex. Unshielded CRTs or Speakers) the cartridge will likely be irreparably damaged.

Causes

 * The Bubble Software cartridge is corrupt.
 * The game failed to load correctly.

Solutions

 * Reseat the Bubble Software cartridge.
 * Replace/restore Bubble Cartridge with a Bubbless cartridge and/or ROM dump of installed game.

Causes

 * Faulty RAM.
 * Bad BIOS ROM.
 * Reset circuitry is malfunctioning or damaged.
 * Corrupt Bubble Memory Cartridge.
 * Bubble Memory Controller is faulty/damaged.

Solutions

 * Replace DIP RAM chips with equivalent SRAM/DRAM.
 * Replace DIP BIOS ROM chip with a freshly burnt EPROM using the bubsys BIOS.
 * Check 74-series logic chips near Bubble Memory Controller using a logic probe.
 * Replace/restore Bubble Cartridge with a Bubbless cartridge and/or ROM dump of installed game.
 * Replace Bubble Memory Controller (if possible).

Causes

 * Malfunctioning / Faulty AY-3-8910 chips.
 * Malfunctioning / Faulty K005289 chip.

Solutions

 * Replace DIP AY-3-8910 chips with working old stock or modern AY-3-8910 compatible chips
 * Replace DIP K005280 chip (if possible).

Causes

 * Faulty VLM5030 chip.
 * Voice volume potentiometer is set too low.

Solutions

 * Replace DIP VLM5030 chip (if possible).
 * Tune the voice volume potentiometer until spoken countdown can be heard.

"Warming up now" screen is corrupt
See example here.

Causes

 * Faulty / bad RAM.
 * Possible glitch.

Solutions

 * Replace DIP RAM chips with equivalent SRAM/DRAM.
 * Allow the system to finish booting.

Disassembly Notes
Under no circumstances should the system be exposed to magnetic tools or unshielded magnetic components. Almost all Konami-branded components are virtually unobtainable, repair at your own risk.

Basic PCB Name
Note model numbers and board revisions here

Basic PCB Name
If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric search.

Related Links

 * Bubble System Wiki (Use Translator) http://www.bubsys85.net/