Digital Equipment FR-902AA-A3, Service Maintenance Manual

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Service Procedures Digital STARION 400i - 900i PC
36 MCS Logistics Engineering - Nijmegen
Main Logic Board Jumpers
Jumper pins allow to set specific computer parameters. They are set by changing the pin location of jumper
blocks. Note that the square pin of each jumper block is pin 1. A jumper block is a small plastic-encased
conductor (shorting plug) that slips over the pins. To change a jumper setting, remove the jumper from its
current location. Place the jumper over the two pins designated for the desired setting. Press the jumper
evenly onto the pins. Be careful not to bend the pins.
CAUTION
Do not touch any electronic component unless you are safely grounded. Wear a
grounded wrist strap or touch an exposed metal part of the system box chassis. A
static discharge from your fingers can result in permanent damage to electronic
components.
Main Logic Board Jumper Settings
Settings shown in bold italics are factory defaults.
Feature Description Setting
CPU clock
75 MHz
90 MHz
100 MHz
J22, open
J21, open
J22, open
J21, jumpered
J22, jumpered
J21, jumpered
CPU core/bus frequency 3/2
2/1 J27, open
J27, jumpered
Recovery mode Normal
Recovery mode J10, open
J10, jumpered
Password clear Normal mode
Password clear (MFG test) J11, open
J11, jumpered
CMOS clear Normal
Discharge J16, pins 1 and 2 jumpered
J16, pins 2 and 3 jumpered