_ DEC-O-LOG for 82XBX

_ DOL, 82XBX-M001, H7231 BBU APR 87

PROBLEM: In the event of an airflow reduction or an over-temperature
condition within the 8200 Configuration I or II systems, the H7231 BBU
(Battery Backup) option may become active.  This condition will occur
if the H7231 was installed "without" the DEC PWR BUS cable connected to
the 877 power controller.  Once the BBU has become active it will supply
a 250 VDC potential to the H7251 regulator within the power supply, this
regulator inturn provides +5B to the memory arrays and 24 VDC to the
blower motor.  If the memory arrays remain active without proper cooling
they will soon overheat and be destroyed.  Another hazard exits without
the DEC PWR BUS connected to the power controller during system servicing.
If power is cycled off via the rear circuit breaker(s), and the front
panel rotary switch remains in the enable position the H7231 will become
active.  If this should occur, again a 250 VDC potential will be supplied
to the regulators, creating a very hazardous service condition. 

FIELD EFFECTIVITY: Retrofit all VAX 8200 systems (82XBX Configuration
1 and 2 to upgrade the Battery Backup Unit H7231-L to Rev. "C1".  This
FCO incorporates the following ECO: 7020826-LTN001, New Part Revision
"B1". Field spares stock should also be upgraded. 

QUICK CHECK: Configuration 1: Open the front panel of the system cabinet
and check for the absence of the DEC PWR BUS Cable running from the 877
Power Controller to the rear of the H7231 Battery Backup Unit.
Configuration 2: With the rear door removed, use a flashlight or other
light source and carefully check at the rear of the H7231 for the absence
of the DEC PWR BUS Cable. 


FCO KIT ORDERING:
EQ-01469-01  FCO, PARTS
FA-04756-01  FCO only


_ DOL, 82XBX-R002, CPU AUG 87

PROBLEM: 1. Cache invalidate. 2. Kernel stack invalid.
3. Incomplete stack. 4. Incomplete stack frames.
5. Processes stack in AST delivery loops. 6. Problem
with new KDB50 diagnostic. 

FIELD EFFECTIVITY: Retrofit all 82XX systems. This FCO
changes Rev. of the kernel to "B1". This FCO incorporates
ECOs: T1001.MK008 and T1001-YA-MK002. 

QUICK CHECK: E23 is 21-20850-BB 


FCO KIT ORDERING:
EQ-01480-XX  FCO, PARTS
FA-04769-01  FCO only
FA-04771-01  FCO only