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HS3 Service Bulletins

HS3-99SB1 Software Recall Rev 1.0 to 1.2.

HS3-99SB2 Current Measurement Errors (Intermittent)

HS3-07SB1 Current Measurement Errors (Intermittent)

HS3-99SB1 Current Measurement Errors

All HS3 product was located and replacement software was issued. A 'Software Watchdog' was incorporated to prevent the processor from getting 'lost' and not have a reset. A starter was reported to 'Lockup' while in coast mode with the interlock enabled, thereby permitting exposures without rotation power.

HS3-99SB2 Current Measurement Errors

A 'JRC' brand 'LF347 amplifier' used on CB572 (Tube Select and Safety) has been determined to have low drive characteristics. The device caused Intermittent Current Measurement as well as Intermittent Safety Detection. Replace the device with another brand or contact the factory for replacements.

Models Affected:
HS3-R Serial Numbers 11-99001 to 11-99027
HS3-RQ Serial Numbers 13-99001 to 13-99003
HS3S-RQ Serial Numbers 15-99001 to 15-99007

HS3-07SB1 Current Measurement Errors (Intermittent)

The multiplexer U3 on CB572 (Tube Select and Current Measurement board) is a CD4053 chip.  The 6502 microprocessor outputs do not reliably select the chip inputs because the voltages of the 6502 system are borderline for the cmos chip.  Replace the CD4053 chip with 74HCT4053 as this chip compatible with the 6502 voltage levels.  This problem took years to track down because sending out the CB572 and sometimes the CB574 (microprocessor board) solved the problem.

Models Affected (All HS3)