Select Language
English
French
German
Italian
Spanish
MENU
Toggle navigation
Products
ESD Bags & Labels
Static Shielding Bags & Film
Metal-In Shielding Bags
Metal-Out Shielding Bags
Shielding Bubble Bags & Film
Shielding Bubble Bags
Shielding Bubble Film
Moisture Barrier Bags
SCS Dri-Shield® 2000 Bags
SCS Dri-Shield® 2700 Bags
SCS Dri-Shield® 3000 Bags
SCS Dri-Shield® 3400 Bags
SCS Dri-Shield® 3700 Bags
SCS MIL-PRF-81705E Type I, Class 1
SCS 3370 Moisture Barrier Bags
Certified Clean Bags & Film
Certified Clean Bags
Certified Clean Film
Ultra Clear Barrier Bags
Antistatic Pink Poly Bags
Pink Poly Bags with Zipper
Pink Poly Bags without Zipper
Antistatic Pink Bubble Bags
Conductive Black Bags & Film
Conductive Black Bags
Conductive Black Film
Gusset Bags
Side Gusset
Stand Up Bottom
Desiccant
Humidity Indicator Cards
Labels & Label Dispensers
BGA Rework
Accessories
Scorpion Rework System
Continuous Monitors
Workstation Monitors
Single-Wire Continuous Monitors
Dual-Wire Continuous Monitors
Equipment Ground Monitors
SCS Ground Master Monitor
SCS Ground Man Plus Monitor
ESD Event Monitors
SCS EM Aware Event Monitor
SCS Static Management Program
SMP Diagnostic Kit
ESD Field Service & Vacuums
Field Service Kits
Vacuum Cleaners
Flooring
Statguard Floor Care System
Statguard Dissipative Floor Finish
Statguard Floor Cleaner
Statguard Floor Neutraliser
Statguard Floor Stripper
Statguard Conductive Floor Epoxy
Floor Matting
Vinyl Floor Matting
Rubber Floor Matting
PVC Floor Matting
ESD Tiles
8400 Series Vinyl Floor Tiles
FreeStyle 8400 Interlocking Tiles
Floor Accessories & Grounding
Straight Cords
Straight Cords with Conical Head
Floor Marking Tape
Copper Earthing Tape & Kit
Adhesive
Adhesive Tape
ESD Footwear
3-Layer Non-Marking Foot Grounders
Heel Grounders with Hook-and-Loop Straps
Heel Grounders with Elastic Back & Hook-and-Loop Straps
Heel Grounders with Elastic Straps & Clip Fastener
Shock Cord Foot Grounders
Snap-loc Heel Grounders
Wescorp Foot Grounders
Disposable Heel Grounders
Disposable Conductive Booties
SCS Standard Style Foot Grounders (One Sole)
SCS Cup Style Foot Grounders (Two Soles)
SCS Specialty Foot Grounders
Footwear & Wrist Strap Testers
Data Acquisition
SmartLog Pro® 2
Footwear & Wrist Strap Testers
Combo Tester X3
Combo Tester
High-Speed/High-Accuracy Wrist Strap & Footwear Tester
High-Speed/High-Accuracy Wrist Strap & Footwear Tester with Output
Compact Wrist Strap & Footwear Tester
Wrist Strap Testers
High Speed/High Accuracy Wrist Strap Tester
Compact Wrist Strap Tester
Portable Wrist Strap Tester
AC Outlet Analyser and Wrist Strap Tester
Calibration Units for Testers
Static Control Garments, Gloves & Masks
Statshield® Smocks
Blue Smocks
Black Smocks
Polo Shirts
Lab Coats & Jackets
Gloves
Masks
Hand Tools
Cleaning Brushes
Dissipative Brushes
Conductive Brushes
Menda Probes
Menda Workstation Tools
Cable Control
Workstation Organisers
Harnessing Wire Threader
Tronex Precision Hand Tools
Cutters
Pliers
Handling & Storage
Ultra Clean Kitting Trays
SMD Storage Products
PCB Storage Products
PCB Racks & Holders
PCB Containers
Hanging Bins
Protektive Pak® Plastek Products
Plastek™ In-Plant Handlers
Plastek™ Storage Containers
Plastek™ Open Bin Boxes
Protektive Pak® Dissipative Corrugated Products
Protektive Pak® Dissipative Corrugated Products
Velostat® Containers
Ionisation
Bench Top Ionisers
Bench Top Mini Zero Volt Ioniser
Bench Top Zero Volt Ioniser
Benchtop AC Ioniser
SCS Bench Top Air Ionisers
Overhead Ionisers
Chargebuster Overhead Ioniser
Overhead Zero Volt Ioniser
SCS Overhead Air Ioniser
Forced Air Ionisers
Ion Python Point-of-Use Ioniser
SCS Ionised Air Gun
Viper Ion Gun
Meters & Measurements
ESD Event Detection
SCS ESD Pro Event Indicator
SCS EM Eye Meter
Body Voltage Meter
Resistance Testers
Surface Resistance Test Kit
Analogue Surface Resistance Meter
Low Resistance Tester
Surface Resistivity Checker
Portable Surface Resistance Probe
SCS 701 Analogue Surface Resistance Meter
Concentric Ring Probes
Cylinder Probes
Portable Charged Plate Monitor
Static Field Meter & Ionisation Test Kit
ESD Survey and Assessment Kits
SCS Ground Pro Meter
ESD Packaging
Foam
Cushioning Foam
Pin-Insertion Foam
Hook-and-Loop Straps
IC Shipping Tubes
Protektive Pak® Dissipative Corrugated Products
Protektive Pak® Dissipative Corrugated Products
Plastek™
Plastek™ Circuit Board Shipper
Rigid Conductive Boxes
ESD Tags
Soldering Supplies
Desoldering Braid
Sea Braid
Lead-Free
One-Step
Quick Braid
ESD Tape
Wescorp™ Antistatic Cellulose Tape
Wescorp™ Antistatic Cellulose Tape with Symbols
Wescorp™ Conductive Grid Tape
Wescorp™ Antistatic High Temp Masking Tape
Wescorp ESD Hi Temp Polyimide Tape
Tape Dispensers
Packaging Tape
ESD Working Surface Matting & Grounding
Working Surface Matting
Rubber Working Surface Matting
Vinyl Working Surface Matting
Shelf Matting
Bench Top Turntables
Working Surface Grounding
Straight Cords
Straight Cords with Conical Head
Link Cords
Earth Bonding Point Cords
Earth Facility & EBP Brackets
Earth Bonding Point Plugs
Earth Bonding Point Bars
Earth Bonding Point Boxes
SCS Grounding Systems
Working Surface Hardware
Workstation Accessories
EPA Warning Signs
ESD Awareness Guide
Document Handling
Ring Binders
Clipboards
Document Wallets & Holders
Maintenance Products & Accessories
Reztore® ESD Surface & Mat Cleaner
Reztore® Antistatic Coating
Reztore® ESD Hand Lotion
Menda Badge Holders
ESD Badge Holders
Menda Connector Covers
Menda Dispensing Bottles
Cone Top Bottles
One-Touch Bottles
Pure-Touch Bottles
Trigger Sprayer Bottles
Take-Along Bottles
Pure-Take Bottles
Twist-Lock Bottles
Flux Dispenser Bottles
Wash Bottles
Bottles Only
Pumps & Stems
Pump & Bottle Accessories
Menda Stainless Steel Drinking Cup
Menda Workstation Organisers
Waste Bins & Liners
Workstation Covers
Workstation Divider
ESD Wrist Straps & Coiled Cords
Single-Wire Wrist Straps
Wrist Strap Sets
Wristbands
Coiled Cords
Dual-Wire Wrist Straps
Wrist Strap Sets
Wristbands
Coiled Cords
Clearance
Bags and Labels
Continuous Monitors
Desoldering Braid
Field Service and Vacuums
Foot Grounders
Footwear & Wrist Strap Testers
Handling & Storage
Ionisation
Menda Dispensing Bottles
Tape
Working Surface Matting & Grounding
Workstation Accessories
Wrist Straps & Coiled Cords
New Products
ESD Services
ESD Survey
EOS ESD Assessment
Product Demonstration
ESD Training
Distributors
Technical
Resources
ESD Library
Webinar
LOGIN
SHOP
RPL
CART (
0
)
$USD
SUBSCRIBE TO OUR EMAIL LIST - Be the first to know
about exclusive deals, tips, new products & more!
Questions And Answers
#
257
List All Questions
Search
List by Category
Question
Are there any reports of ESD damage to BIOS and system chips when installing or removing expansion boards in an ATX powered computer case (there is a standby voltage on most of the ISA and PCI board pins)Also, I was prodding around my system board with the main power off, but the unit was still plugged into the wall outlet, and the standby power was still active. I was probing to determine the standby voltage (which was around 50-100mV) and I may have shorted some leads of some chips in the process, (due to the large size of the voltage probe in comparison to the chip leads)Would a voltage level of this magnitude have caused any damage to system BIOS chips or expansion card components? - David Chan, Waterloo, Ontario, Canada
Answer
Bios and system chips when installing or removing expansion boards are highly sensitive to ESD damage and should be handled properly, according to standard ESD control methods. Your specific question regarding standby voltages on the system board falls into EOS (Electrical OverStress). If electronic chips are powered up and any of the I/O (input/outputs) are shorted, you can EOS the device causing permanent damage. The voltage of 50 to 100 millivolts is more in line with the emf (electro-motive force) between two dissimilar metals and may not necessarily be due to the local power supply or capacitor bank. Either way, it is highly advisable to not have your power supply plugged in when operating on your PC, but rather remove the power cord and attach just a ground cord to a localized ESD dissipative mat/work surface. Also, you should wear an ESD wrist strap and ground yourself when handling these sensitive devices. Additional Info: How to prevent unwanted ESD from cruising through your PC? Remove all unnecessary objects, especially non conductors from around your PC. Make sure you have a proper power ground for your PC and peripherals. Ground all conductive objects that come in contact with your PC. Ground all conductive objects that are within the near vicinity of your PC. Keep your monitor screen clean with an antistatic spray or wiping cloth. Ground yourself and anyone else working near or on your PC when repairing or adding components. NOTE: Make sure there is no exposed high voltage (<250VAC) within your reach when grounded. For repairs or add-ons, keep your PC components in their shielded bags during transportation. Before removing PC components from shielded bags, place them on a grounded work surface. Remove the PC components only when you are grounded via your wrist strap. EOS? ESD? When you walk across a carpet and then reach for a door knob and get ZAPPED, you have experienced an ESD event. As you walked across the carpet, you charged your body with 6,000 - 20,000 Volts by means of triboelectric generation. When reaching for the door knob, the difference in voltage between the door knob and your body became so great that the air physically broke down and created an electric current discharge. The discharge occurred to bring the voltage of your body to the same voltage of the door knob. If the door knob was your computer keyboard the discharge (current) could travel through the I/O cables into your computer and cause an electrical overstress to any IC in its path. An overstress voltage as low as 10 Volts could permanently damage a CMOS Chip (IC). The computer can receive charges/discharges from any contact via the keyboard, chassis, drive doors, connecting cables, monitor, etceteras. The most common occurrence of an ESD event effecting the PC is through the handling of components when upgrading, adding, changing, troubleshooting or repairing your PC or other electronic equipment. These failures can be latent or catastrophic. Latent failures will not be evident at first but may cause problems at a later time leading to catastrophic failures. Catastrophic failures are noticed immediately because your system will “crash” or have an equipment malfunction.
Related Categories:
Test Equipment
If you have found this Q/A useful, please rate it based on its helpfulness.
This question has been rated:
(
0
% at
0
Ratings)