Troubleshooting Methods

1
Troubleshooting Methods

• Making your own flow chart/punch list

2
Spheres of Control
Operating System Software
Logical
CMOS ESCD BIOS
Physical/Hardware
Firmware
Physical
3
A summary model
Software Applications
Software Operating system
Firmware BIOS/CMOS/ESCD
Hardware backplane with power, chipset, and
communication busses
4
Specific Management Functional Areas (SMFA)
Security Auditing
(Network Operating System)
Configuration Fault Performance
5
Save Energy Take the Bus
Functional paths

• Power/Cooling
• Address/Data
• Control

6
Steps to Define/Isolate/Resolve

• Define the problem scope
• hard/soft power, addressing, data, etc.
• Determine the best level for resolution
• Isolate ONE suspect source at a time
• Resolve your defined problem scope if possible,
  replicate on a different system
• Communicate/Transmit/document

DIRECT a troubleshooting acronym
7
Troubleshooting Guidelines

• Visually inspect and manipulate (pull/reseat)
• Use a good FRU where appropriate for testing
• Confirm BIOS/OS configuration
• Replace labor-intensive and/or expensive parts

8
1st Round - Visual inspection

• Have you traced all functional busses?
• Follow the physical paths supporting power and
  address/data transfers
• Isolate and reseat each connector
• Where appropriate, use either a different
  connector or different expansion slot

Do you know the typical symptoms of a bad
cable connection?
9
Power Bus

• PC or peripheral is dead no power indicator
• Short, lead pull-through, trace breaks/ board
  cracks
• AC source/ground fault circuit interrupt
• PC or peripheral operates intermittently

10
Data/Address Bus

• Check orientation of cable connections.
• Where is pin 1? Is the connector keyed?
• Is the bus terminated correctly?
• Are the devices properly identified on the bus?
  In the OS? In the BIOS?
• Has some component or configuration recently
  changed?

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The Busses and support stuff

• Legacy
• ISA
• MCA
• Extended ISA
• VESA Local Bus (VL-BUS)
• Non-Legacy
• PCI
• AGP (not a bus) and PnP (not a bus)

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Software controlled Resource Allocations

• Plug and Play (PnP) requires
• PnP device (with BYOB)
• PnP system BIOS
• PnP OS software
• Extended System Configuration Data List (ESCD)
• PCI Bus IRQ Steering

13
1st Round - Visual inspection

• Have you traced all functional busses?
• Follow the physical paths supporting power and
  address/data transfers
• Isolate and reseat each connector
• Where appropriate, use either a different
  connector or different expansion slot

Do you know the typical symptoms of a bad
cable connection?
14
2nd Round - BIOS config. management

• Confirm CMOS settings for power and speeds
• Confirm CMOS settings for expansion bus devices.
  Do you have legacy devices in the system? Do
  they use jumper or software settings?

What are the typical symptoms of poor or
incorrect BIOS settings?
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Control Bus

• Input/Output (I/O) Port Address
• I/O Memory Address
• Interrupt Request Line (IRQ)
• Direct Memory Access (DRQ)
• Legacy ISA/ICU or PnP compatibility
• PCI bus IRQ Steering and PnP

16
3rd Round - OS config. management

• Using Device Manager, confirm system resource
  allocations
• Confirm the proper installation and current
  versions of driver software
• Typically keep driver software updated and
  current. Document ALL software updates.

What are the typical symptoms of an incorrect
driver?
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To be Continued
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Connectors

• DB pins 9/25/37 male/female
• DIN pins 6/5 regular, mini a European
  standard
• RJ 45/11(telco)/14(telco)4 twisted pair 2
  twisted pair 2 twisted pair
• BNC British Naval Connector
• Audio old RCA plug
• USB tiered-star, multidrop 12Mbps topology
  supporting 127 devices, 7/hub, 5 tiers deep

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Recommended Standards and Specifications

• Centronics de facto standard (female DB25) for
  parallel connections
• Extended Capabilities Port (ECP) IEEE 1284
• Enhanced Parallel Port (EPP) IEEE 1284
• EIA RS-232 - describes signaling interface not
  the connector
• Universal Serial Bus (USB) Standard a
  mult-tiered, connection standard for common I/O
  devices
• Firewire IEEE 1394 scalable, peer-to-peer
  architecture using memory-based addressing

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IEEE 1284 Standard

• Formalized use of parallel connections
• Supports 5 modes of operations
• Legacy
• Compatibility 8 data, unidirectional
• Nibble mode software enabled, sends data to PC
• Byte mode hardware enabled, sends data to PC
• Non-legacy
• ECP a hardware protocol supporting half-duplex,
  loosely coupled data transfers for printers and
  scanners
• EPP a hardware protocol supporting half-duplex,
  high-speed communication does not always work
  well with pre-1284 devices

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Suggested USB Punchlist

• BIOS support enabled? IRQ assigned?
• Host PC have an integrated USB port?
• Has the OS detected and enabled the Host
  Controller? Universal or Open Controller? Is
  there a USB Root Hub device?
• External cabling within specifications? If a
  device does not appear, isolate the port and hub.