Service Procedures
Digital DECpc LPv/LPv+
32
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.
LPv Main Logic Board Jumper Settings
Settings shown in
bold italics
are factory defaults.
Feature
Description
Setting
Onboard VGA (IRQ9)
Disable IRQ9
Enable IRQ9
J25, open
J25, jumpered
Onboard VGA
Disable VGA
Enable VGA
J23, pins 1 and 2 jumpered
J23, pins 2 and 3 jumpered
Factory test
Normal
MFG test
J28, open
J28, jumpered
Video display type
Mono monitor
Color monitor
J29, open
J29, jumpered
Flash ROM update
Enable
Disable
J13, Jumpered
J13, open
CPU clock input
50 Mhz
40 MHz
33 MHz
25 MHz
J18, open
J19, open
J20, open
J18, jumpered
J19, open
J20, open
J18, jumpered
J19, open
J20, jumpered
J18, open
J19, jumpered
J20, jumpered
