Desktop Boards
Desktop Boards
Electrical overstress prevention

Contents
What is electrical overstress (EOS)?
What causes EOS?
Recommendations to prevent EOS
Preventative action to reduce damage

What is electrical overstress (EOS)?

  • EOS is caused by an unusual spike in voltage applied to the system that causes damage at the component or board level, rendering system or component failure. The event usually lasts from microseconds to seconds (short pulses range in the nanoseconds).
  • EOS damage is typically not visible because the damage is at the transistor level.

electrical overstress

  • Signs of EOS include:
    • Blown metal line – Thermal Damage
    • Molten damage – High Power Consumption
    • Electrostatic Discharge (ESD) is a subset of EOS. The event occurs within pico to nanoseconds and is usually caused by human contact. The impact is similar with blown metal lines.

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What causes EOS?

Electrostatic Discharge

  • Hot Plugging. Any time you plug a cable or component into a running computer you are hot plugging and can cause Electrical Overstress.
  • Power Supply. Power supplies can cause electrical overstress if they fail to regulate voltage and amperage properly. Power spikes can damage components.
  • Inadequate Work Procedures. This includes incorrectly positioning components, not completely seating connections, or improper powerup and powerdown sequences.
  • Ground Bounce. Ground bounce is a fast current switch resulting in high voltage due to insufficient grounding points and can be caused by turning on a large current device, such as a motor, or other electrical component.
  • High Potential Testing. Hi-pot testing can cause EOS through surges and power spikes while testing.

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Recommendations to prevent EOS

  • Check all test and assembly equipment are grounded
    Check all test and assembly equipment are grounded
  • Monitor electrical lines (AC) for noise
    Monitor electrical lines (AC) for noise
  • Ensure operators are tightening loose connections to prevent intermittent events
    Ensure operators are tightening loose connections to prevent intermittent events

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Preventative action to reduce damage

  • Correct insertion of devices
    • Post simple EOS guidelines for training and reinforcing proper techniques
    • Check connections - Cable connections, add-in card insertion, memory, processor, etc.
  • Beware of powered insertions and removals
    Beware of powered insertions and removals
  • Never hot swap devices.
  • Promote awareness of stand-by power. Power can be present on the motherboard when it appears off.
  • Don’t add or remove devices when stand-by current is present, as it can damage devices and the motherboard.
  • Remove AC power when adding or removing devices to the system.
    • Assembly – connect AC last
    • Disassembly – disconnect AC first
  • Battery
    • Avoid touching the battery - Shorting top (+) to board can cause EOS damage to the board
      Avoid touching the battery
  • During test and debug, avoid:
    • Hot swapping
    • Use of incorrect test sequence
    • Foreign material on board or in connectors
      Test and Debugging

This applies to:

Intel® Desktop Board D2500CC
Intel® Desktop Board D2500HN
Intel® Desktop Board D2550DC2
Intel® Desktop Board D2550MUD2
Intel® Desktop Board D2700DC
Intel® Desktop Board D2700MUD
Intel® Desktop Board D410PT
Intel® Desktop Board D425KT
Intel® Desktop Board D510MO
Intel® Desktop Board D525MW
Intel® Desktop Board DB65AL
Intel® Desktop Board DB75EN
Intel® Desktop Board DB85FL
Intel® Desktop Board DH55HC
Intel® Desktop Board DH55PJ
Intel® Desktop Board DH55TC
Intel® Desktop Board DH57DD
Intel® Desktop Board DH57JG
Intel® Desktop Board DH61AG
Intel® Desktop Board DH61AGL
Intel® Desktop Board DH61BE
Intel® Desktop Board DH61BF
Intel® Desktop Board DH61CR
Intel® Desktop Board DH61DL
Intel® Desktop Board DH61HO
Intel® Desktop Board DH61KVCH
Intel® Desktop Board DH61SA
Intel® Desktop Board DH61SKCH
Intel® Desktop Board DH61WW
Intel® Desktop Board DH61ZE
Intel® Desktop Board DH67BL
Intel® Desktop Board DH67CF
Intel® Desktop Board DH67CL
Intel® Desktop Board DH67GD
Intel® Desktop Board DH67VR
Intel® Desktop Board DH77DF
Intel® Desktop Board DH77EB
Intel® Desktop Board DH77KC
Intel® Desktop Board DH87MC
Intel® Desktop Board DH87RL
Intel® Desktop Board DN2800MT
Intel® Desktop Board DP55KG
Intel® Desktop Board DP55SB
Intel® Desktop Board DP55WB
Intel® Desktop Board DP55WG
Intel® Desktop Board DP67BA
Intel® Desktop Board DP67BG
Intel® Desktop Board DP67DE
Intel® Desktop Board DQ57TM
Intel® Desktop Board DQ57TML
Intel® Desktop Board DQ67EP
Intel® Desktop Board DQ67OW
Intel® Desktop Board DQ67SW
Intel® Desktop Board DQ77CP
Intel® Desktop Board DQ77KB
Intel® Desktop Board DQ77MK
Intel® Desktop Board DQ87PG
Intel® Desktop Board DX58OG
Intel® Desktop Board DX58SO
Intel® Desktop Board DX58SO2
Intel® Desktop Board DX79SI
Intel® Desktop Board DX79SR
Intel® Desktop Board DX79TO
Intel® Desktop Board DZ68AF
Intel® Desktop Board DZ68BC
Intel® Desktop Board DZ68DB
Intel® Desktop Board DZ68PL
Intel® Desktop Board DZ68ZV
Intel® Desktop Board DZ75ML-45K
Intel® Desktop Board DZ77BH-55K
Intel® Desktop Board DZ77GA-70K
Intel® Desktop Board DZ77RE-75K
Intel® Desktop Board DZ77SL-50K
Intel® Desktop Board DZ87KLT-75K

Solution ID: CS-021685
Last Modified: 25-Sep-2014
Date Created: 09-Oct-2005
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