Troubleshooting continued

1
Troubleshooting (continued)

• Making your own flow chart/punch list

2
Installation Overview

• Install device or add-on card.
• Is it legacy? Configure system resources.
• Install device driver.
• Confirm hardware/software configuration settings.
• Install application software.
• Test the configuration change.

3
Installing a hardware device

• Protect PC from ESD.
• Modify PC chassis to accommodate device.
• Insert device/add-on card in appropriate location
  inside chassis.
• Secure the device and connect power, address, and
  data lines.
• If appropriate, configure resources on device.
• If appropriate, confirm BIOS settings.
• If appropriate, confirm system settings.
• Test the device.

4
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
5
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

6
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?
7
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?

What are the typical symptoms of poor or
incorrect BIOS settings?
8
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?
9
To be Continued
10
Topics

• Sound cards
• Keyboards
• Pointing Devices
• Modem cards

11
A Generic Sound Card
MICLinein
AudioAmp
ADC
DSP
Synthesizer
ROM
CD Audio
SpkrLineout
RAM
Mixer/Filter
AudioAmp
MIDI/joystickinterface
Bus Interface circuits
PCI or Expansion Bus
12
Sound Card

• Sound waves translated to analog electrical
  signals via microphone
• Analog signals amplified by sound card then
  digitized
• Data and control information is compiled into a
  file format, WAV, and saved to a storage device
  like drive or CDROM
• WAV file read and translated back to analog form.
  If stereo, data divided into two channels
  separately converted to analog signals,
  amplified, then sent to speakers.
• Speakers convert analog signals to pressure waves.

13
Sampling (digitization)

• An analog wave is measured periodically and
  voltages are converted to digital numbers by an
  analog-to-digital converter (ADC).
• A sound file is the digital equivalent of an
  analog waveform.
• One issue is capturing sufficient wave levels to
  reproduce analog wave. Distortion resulting from
  low sampling is called aliasing.
• Sampling should occur twice as fast as highest
  frequency. Sampling rates should be at least 44
  kHz. High rates require more disk space.
• Precision of each each sample (bit depth) is also
  important. Most boards have a 16-bit depth
  (216 or 65,536 levels).

14
MIDI

• Musical instrument digital interface (MIDI) is a
  standard protocol defining hardware, software,
  and electrical connections using a synthesizer
  chip.
• A MIDI file is a set of instructions for playing
  musical notes including duration, pitch, and
  timing specifications using relatively small
  storage space compared to WAV files. MIDI is not
  a sound but a blueprint for the sound or sheet
  music.
• The blueprint includes voices of individual
  instruments and how to play the music. Sound
  cards can have, for example, 32 voices playing
  simultaneously polyphony.

15
A sound card

• On a sound card, the core component is the
  digital signal processor (DSP) which is a chip
  designed to manipulate digital data.
• A ROM chip contains programs that run the DSP and
  other circuitry on the board. RAM provides
  support for DSP operations and a buffer for data
  transfer to the system expansion bus.
• Incoming signals from a microphone pass through
  an amplification stage and then to the ADC.
• Signals from the line input are typically
  stronger and require less amplification.
• Output signals are sent to a mixer for each
  speaker (stereo) before leaving the board where
  CD audio, DSP sound output, and synthesizer
  output are combined in a single analog channel.

16
Audio Terminology

• Decibels (dB) logarithmic increasing stereo
  power does not increase loudness linearly. Small
  changes in dB relate to large changes in power
  or wattage.
• Frequency response is range of frequencies
  handled uniformly. Sound output is stable across
  some working frequency range. The cheaper the
  card, the greater the roll-off of signal
  strength bass and treble are weak.
• Signal-to-Noise Ratio (SNR) is maximum
  undistorted signal divided by electronic noise
  (hum and hiss) generated by the board in dB.
  Boards with SNR below 75dB have audible noise.
• Total Harmonic Distortion (THD) is the unwanted
  harmonic frequencies produced. Harmonic
  frequencies or overtones are integer multiples of
  original signals.

17
Microphones

• Dynamic usually hand-held or desktop. Large
  response range and better sound than condenser.
  Diaphragm elements can create electric current
  for sound board signal.
• Condenser Typically come with computers, not as
  good a response rang as dynamic mikes smaller
  diaphragm. Uses phantom low-level power from
  the sound board.
• Electret condenser Condenser mikes with built-in
  power.
• Microphones must conform to the board
  specifications. Not all sound cards have control
  to enable/disable power to support different
  mikes.

18
Sound cabling connections

• Speaker output
• Microphone input
• Line input
• CD audio cable between CDROM and board
• CDROM drive interface
• MIDI or joystick (15-pin)

19
Sound Board Punchlist

• PHYSICAL
• Confirm speakers connection and power. Hisses and
  hums can be caused by EMI or RFI
• Confirm volume levels on the speakers
• Confirm mixer and master volume levels on the PC
• Confirm physical connection of boards and
  installation (and date) of drivers
• Confirm BIOS settings for sound devices
• Driver
• Confirm sound files are installed correctly and
  the file is a valid .MID or WAV
• Support Resources
• Confirm system resource allocations do not have
  conflicts
• Confirm applications have correctly selected and
  configured the sound devices

20
To be Continued
21
Keyboards

• Mechanical vs Membrane key switch on keyboards
• Keyboard interface chip (onboard) interprets the
  keyboard matrix and sends single byte key (or
  scan) code in form of a make and a break code
  (Typematic Delay and Repeat Rate in KB
  properties)
• Keyboard controller (KBCs aka virtual 8042) now
  incorporated into chipset support different
  languages.
• QWERTY vs Dvorak (AOEUI in left home row)
• Important signals are KBCLOCK, KBDATA, and signal
  ground.
• Older XT keyboards were simplex AT keyboards are
  half duplex for programming keys.
• What happens during POST when a KB fails?

22
Mouse

• One of a family of pointing devices (mouse,
  trackball) that move a cursor across the GUI. A
  software driver generates the cursor and, based
  on hardware-generated signals, moves the cursor
  in the positional space of the display area.
  Mouse gestures (clicks, drags, drops) sometimes
  in combination with keyboard input, activate
  programmed methods associated with icons on the
  GUI.
• Three components a hard signal generator, a
  software driver, and an application interface.

23
Mouse Construction

• A hard rubber ball contacts two actuators that
  register movement in an X (horizontal, left to
  right) and Y (vertical, up or down) coordinate
  system. The generated signals of the ball AND
  mouse buttons represent movement and action
  correlating with cursor movement and mouse
  gestures on the GUI.
• Mechanical vs Optomechanical sensors -
  optoisolator

24
Sensor Layout of optomechanical pointing device
Y-pulses
Roller
Mouse Ball
Roller
Optoisolator
X - pulses
25
Pointing Device Interfaces

• Legacy
• Serial mouse using DB9F or DB25F in COM ports
• Bus mouse uses its own standalone controller
  board and dedicated bus connector (mini- DIN)
• Non-legacy
• 6-pin mini-DIN design connector used to provide
  interface for mouse AND KBs on PC
• USB connection off a USB hub or other device

26
Pointing Device Punchlist

• For USB
• Check OS version, check software driver
• Check product firmware version.
• Confirm Universal Serial Bus Controller is
  recognized by Device Manager
• Confirm USB controller and ports are enabled and
  recognized by BIOS/OS
• Confirm settings of pointing device
• Confirm software drivers are loaded properly

27
To be Continued
28
Video Punchlist

• The Video Graphics card hard
• VRAM type, quantity, speed, access
• bus connection (AGP), chipset, RAMDAC only for
  analog
• Supplemental processing support - hard
• accelerator cards
• Trend toward incorporating more graphics
  capabilities into chipsets Intel 810 / 815
  incorporates a GMH
• The Monitor hard
• CRT (analog) / Flat panel (digital)
• The Device drivers - soft

29
OS and I/O output
Video card
Memory
RAMDAC
Chipset
Service properties resolution, color depth,
refresh rate
30
Memory Issues

• Resolution (Bit Map Size) RAM
• 640 x480 1.0 MB
• 800 x 600 (standard 16 color) 1.5 MB
• 1024 x 768 (preferred) gt 2.0 MB
• VRAM is double-celled RAM allowing simultaneous
  read/write
• Standard configs minimum 4 MB/ 8 MB

31
RAMDAC

• Converts digital RAM to analog CRT signals

OnBoard Memory RAM/VRAM
RAM Digital to Analog Converter
Analog Display
At 16 bits, a screen image 1024 x 768 requires a
1.5 MB bit map. This bit map is optimally
refreshed (vertical refresh) 75 times a second.
32
Video Graphics Cards

• Display modes GUI or TUI
• Resolution pixel count
• Color palette TTL vs Analog signals
• Scan rate Monitors and cards must agree

33
The monitors

• Transistor to Transistor Logic (TTL) -
• Monochrome Display Adapter (MDA)
• - 22 (4 colors) (actually one color/shades)
• Hercules Graphics Card (CGA)
• Color Graphics Adapter (CGA)
• - 24 (16 colors) (RGBintensity)
• Enhanced Graphics Adapter (EGA)
• Analog signal -
• Video Graphics Array (VGA)
• SVGA and UVGA lack of standards

34
CRT- based Video Monitors

• Legacy -
• TTL- based MDA / CGA / EGA up to 640 x 350
  pixels
• Non- Legacy -
• Analog-based VGA is THE basic configuration
• Super VGA is current standard

35
The Works
Grille or(shadow mask)

• RAM DAC digital to analog

Pixels on Phosphor Screen
Magnetic Yoke
3 Guns RGB
H/V Deflection Coils
Analog signal scans across screen directed by
deflection coils
36
The Aperture Grid

• Dot-trio Shadow Mask
• A thin sheet of perforated metal in front of the
  screen. Each hole represents a single pixel.
• Aperture-grille
• A grid of wires between the screen and the
  electron guns. A Slot-mask uses a shadow mask
  with long and thin openings rather than dots.

37
Terminology

• Trinitron vs Invar slotted aperture grill vs
  dot
• Multisync adapts scan rates automatically
• Dot pitch image quality
• Dot size determines max resolution
• Color depth number of bits per color
• 24 16 color base VGA
• 28 256 color mode 224 True color
• Scanning
• Non-interlaced vs interlaced
• Aspect ratio 43
• Vertical (refresh) frequency 75 Hertz ( no
  flicker)
• Horizontal scan rate Higher resolution, higher
  KHz

38
To be Continued
39
Modems

• Modem Modulation-Demodulation
• UART 16550a converts bussed data into a
  serial bit stream.
• Internal vs external modems using COM2
  externals have power source and external LEDs but
  no UART
• DTE/DCEData Terminal /Data Circuit
  (communication) Equipment
• RJ-11/14 (telephone jack) connectors
• Dual-tone Multi-frequency (DTMF) dialing signals
  - the touch-tone frequencies used to call the
  far side.
• Hayes AT Command Set (de facto) - control and
  data modes
• Result code refers to number or verbose text
  messages the modem in control mode will generate
  upon processing a command string
• RS-232 protocol the inter-device communications
  are conducted
• DSVD dual simultaneous voice and data using, in
  addition to modem, a sound card, microphone, and
  speakers.

40
Modem Processes

• Data is translated from parallel to serial and
  back again. Serial data is converted to an analog
  signal, then typically placed on a plain old
  telephone system, POTS. The data flow is
  controlled by the modem modulator circuitry and
  UART 16550a. A second RJ connector is often
  provided to check the line status.
• The POTS interface passes data to a demodulator
  on the far side of the connection. After
  demodulation, the serial data is passed to the
  far side UART which converts serial bits to
  parallel words that are placed on the far side
  expansion bus.
• DTMF signals address the far side modem. The
  incoming ring alerts the UART to negotiate a
  connection. A PC or modem speaker supports the
  sound of dialtone and handshaking squeal.
• The controller circuitry mediates BOTH control
  and data operations. Default and permanent
  settings are stored in NVRAM

41
Modem Negotiation

• Communications begin when application software
  attempts to establish a connection.
• Software (DTE) signals at a COM port for a
  connection UART asserts DTR
• Modem (DCE) responds with DSR.
• Serial port receives DSR and tells software to
  proceed with data. BOTH DTR and DSR are high.
• Software sends init string thru COM port to DCE.
• In command mode, modem goes off hook, dials,
  and rings.
• When far (remote) side picks up, near side sends
  carrier tone, far side detects carrier tone, it
  returns higher pitch. Near (local) side responds
  with CD and negotiates parameters.
• DTE sends RTS to DCE DCE answers DTE with CTS.
  DCE uses CTS for flow control. When software is
  finished, DTR goes down.
• Remote modem communicates by dropping carrier
  signal local DCE detects loss of carrier
  (Dropped Carrier).

42
Datacom Interface
DTE
DCE
DCE
DTE
Protocol
Transmission Channel
Software that enables communication
43
Signal modulation

• In the beginning, each analog signal, called a
  baud carried digital information in the form of
  bits. Baud rate was equal to the transmission
  rate of one bit on one baud (bps or bits/sec).
  Newer encoding schemes send multiple bits on
  every signal transition or baud. Baud rate is no
  longer equivalent to bps.
• Encoding is different from data compression. The
  latter replaces repeating sequences with symbols
  or tokens to convey the data.

44
Terminology

• Three characteristics of a sinusoidal waveform
  amplitude, frequency, and phase. Each can
  represent one bit.
• Amplitude, measured in V, is how far above or
  below the zero axis a wave travels.
• Frequency, measured in Hz, is the number of times
  the wave is repeated in a given period of time.
• Phase, measured in degrees, is positioning based
  on time to travel 25, 50, or 75 of a wave.

45
MNP Standards

• Microcom Networking Protocol (MNP) A standards
  set composed of 10 class designations for error
  correction and data compression rather than data
  transfer.
• Both DCEs must support MNP. Standard is
  hierarchical with more advanced classes adding to
  and improving features of earlier classes and
  therefore backward compatible. For example, MNP
  Class 10 is a more powerful version of MNP class
  4.

46
Communication Standards

• Bell Standards up to 1200 bps obsolete
• International Telecommunications Union (ITU)
  (formerly CCITT) Standards characterized by V.xxx
  which, like RS 232, refers to a standard. Bis
  is second version, ter or terbo refers to third
  version.
• V.42 only ITU error correcting procedure for
  V.22, V.32 and related versions. Link Access
  Procedure for Modems (LAPM). Degrades to MNP4.
• V.42 bis combines Lempel-Ziv compression (cf.
  PKZIP) with V.42 LAPM. Thus, a 14.4 Kbps modem
  can transmit 57,600 bps using this standard.
• V.92 is standard for 56 Kbps has a 48 Kbps
  upstream.

47
File Transfer Protocols

• In addition to data transfer and compression
  protocols, data packaging is not defined by ITU
  or MNP. Modems pass bits NOT files.
• Communication software located on the DTE
  provides file transfer protocols they pass files
  not bytes or bits.
• Examples are Xmodem, Ymodem, Zmodem (with
  recovery features and a 16-bit CRC), and Kermit
  (for accessing mainframes).

48
A modem punchlist

• Confirm operation of telecommunication resources.
• Confirm cabling and power
• Verify system resource allocations including CMOS
  settings for integrated devices
• Confirm software settings such as an AT command
  string used during initialization.
• Confirm modem operation for damage from
  electrical transients and faulty surge
  suppression
• Configure the modem command processor in echo
  mode (ATE1) using ATZ to reset the device and
  ATF to restore factory defaults.

49
AT (ATtention) Command Set

• All begin with AT hence AT commands strings up
  to 40 characters long. Also other subsets like
  AT and AT commands. Programmable
  information can be written to modem memory
  locations (S registers) contents is stored in
  NVRAM ATZE1Q0V1
• Attention AT
• reset to power-on defaults Z
• enable echo mode E1
• Send result codes to DTE Q0
• Use Verbose translations V1
• Result code OK (0), CONNECT(1), RING (2), NO
  CARRIER(3), ERROR(4), NO DIAL TONE(6), BUSY(7)

50
A init (or command) string

• This initialization (init) string is passed to
  the modem during power up by communication
  software. Always a continuous line of
  characters
• ATS00B1H1W
• Do not answer incoming calls S00
• Use CTS flow control B1
• Use a fixed DTE rate H1
• Store parameters in NVRAM W

51
Communication Issues

• Modem settings (such as 8 data bits, no parity, 1
  stop bit) must agree for inter-modem
  communication.
• Replace all (legacy) UARTs that are NOT 16550A.
• Line noise and transmit and receive levels
• System processor limitations are issues with
  WinModem devices.
• Disable call waiting feature (70 on most local
  phone). Set S10 to a higher value to tolerate
  longer carrier signal loss to avoid dropping the
  connection.
• Automatic timeout will drop an inactive line
  after a specified period.
• System lock up can occur when one of the DTE has
  been flowed off, the flow control character has
  been sent. Check these settings for differences
  between the two modems.
• Modem initialization strings must be correct to
  utilize all DCE features.

52
Analog Loopback Self-Test
53
Analog Loopback Test
54
To be Continued