Frenzy repair log – RAM pattern on start


Repair cost:  $20

Symptom: 3 beeps, colored RAM pattern on startup

Diagnosis: Interconnect cables bad (were previously removed & reseated to test another board)


  • 9/23/09 – Replaced 3 connectors with SCSI cables.  No change.  Found DIP switch thrown which was causing it to stay in test mode.  Flipped SW1 open and game booted.


Self-test beep pattern on start
A series of 8 self-tests occurs each time the game is powered on, or reset.  The LED is on the ZPU-1001 board and each flash is accompanied by a tone.  The test will stop at the malfunctioning circuit, provided all the boards are connected properly.

1st beep – ROM circuits on the ZPU board
2nd beep – “scratch pad” are of the RAM on the ZPU-1001 board
3rd beep – Screen RAM on the VFB-1000 board
4th beep – RAM circuits on the BSC-1000 color board
5th beep – Shifter/flopper circuits on the VFB-1000 board
6th beep – Arithmetic and Logic Unit (ALU) on the VFB-1000 board
7th beep – Interrupt and Non-maskable Interrup (NMI) circuit portions which are on both the ZPU-1001 and VFB-1000 boards
8th beep – If the game still does not work, malfunction is in a circuit outside of the self-test program

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