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I
Ice Czar
Guest
Its been awhile since I posted my ESD rant 
and since im now the mod of Power supplies...
It is a power issue, more or less, its certainly related
first up
ESD Precautions and Practices
The ATX motherboard specification maintains +5VSB power to the motherboard
unlike PC/XT, AT, Baby AT and LPX form factors that employed a manual switch to turn on the power to the motherboard, the ATX form factor employs a "soft power" scheme
allowing software control of power, allowing the OS or other ap to turn the computer off, it also allows wake on LAN or Wake on WAN. Since there is a low level of power supplied to the board at all times, you need to address this whenever your swapping out components
the ideal solution is to unplug the power supply from the socket then ground the case with an alligator clip to a seperate ground point and use a wristrap to ground you
the alternative method is to turn off the PSU with its own switch
reliable only if the board has a 5VSB LED indicator on it
at which point you know the board is unpowered, yet the case is still grounded via the AC Socket
the alternative method if there is no switch on the PSU and LED mobo power indicator is to unplug the PSU from the wall socket, then disconnect the main power connector and plug the PSU back into the AC Socket, where once again you have the case grounded
keep in mind that typically the PSU physically contacts the case with a metal to metal contact, at least in the past, and would have at least some contact via the screws, but these adys with painted cases and supplies, some augment that with a grounding strap for the PSU itself (very typical in server supplies where they take no chances with contact)
and religously touch a bare metal surface in the case to ground yourself when swapping componets (this is very typical in here with enthusiasts)
but all in all wristraps are cheap and so are alligator clips and a bit o wire
a grounded work pad is also a good investment, as is being aware of how large a role the lack of humidity has in ESD events, especially in Winter when hot air heating desiccates the moisture out of the air
(see I live on the Rocky Mountain High Dessert Plateau, where its already dry and in Winter with central home heating I humidify the environment when working on components)
ESD Reference
http://www.ewh.ieee.org/r10/bombay/news2/story11.htm
"According to (not so) recent studies conducted by the AT & T Bell labs, 25 % of all component failures today are related to E.S.D and out of all defective components that arrive 50%are damaged by E.S.D. the annual damage due to these failures is estimated at 25 Billion dollars"
An Integrated Circuit (IC) consists of several transistors fabricated on one chip. Due to the advances in L.S.I and V.L.S.I thousands of transistors are crowded on a single chip. By decreasing the thickness of the gate oxides and interconnecting lines the manufacturers hope to achieve much higher speeds at very low power consumption. But under these conditions if the Electrostatic Discharge passes through an IC and the current that results is not diverted or diminished by a suitable protective mechanism, the discharge may raise the temperature of the junction inside the component to melting point which will cause damage to the junction or interconnecting lines. Since surface mount devices are smaller than conventional ICs they are even more susceptible to E.S.D damage. E.S.D causes two main types of failures: -
1. Immediate failure where the effect can be readily seen by the equipment manufacturer.
2. Delayed failure where the device is damaged only upto the point where it may pass quality control tests, but wears out sooner than its rated time
http://www.esda.org/esdbasics1.htm
Table 2
Examples of Static Generation
Typical Voltage Levels
Means of Generation .........10-25% RH ......65-90% RH
Walking across carpet ......,35,000V ...........1,500V
Walking across vinyl tile ....12,000V ............250V
Worker at bench ................6,000V .............100V
Chair with urethane foam ..18,000V ...........1,500V
ESD DamageHow Devices Fail
Electrostatic damage to electronic devices can occur at any point from manufacture to field service. Damage results from handling the devices in uncontrolled surroundings or when poor ESD control practices are used. Generally damage is classified as either a catastrophic failure or a latent defect.
Catastrophic Failure
When an electronic device is exposed to an ESD event it may no longer function. The ESD event may have caused a metal melt, junction breakdown, or oxide failure. The device's circuitry is permanently damaged causing the device fail. Such failures usually can be detected when the device is tested before shipment. If the ESD event occurs after test, the damage will go undetected until the device fails in operation.
Latent Defect
A latent defect, on the other hand, is more difficult to identify. A device that is exposed to an ESD event may be partially degraded, yet continue to perform its intended function. However, the operating life of the device may be reduced dramatically. A product or system incorporating devices with latent defects may experience premature failure after the user places them in service. Such failures are usually costly to repair and in some applications may create personnel hazards.
It is relatively easy with the proper equipment to confirm that a device has experienced catastrophic failure. Basic performance tests will substantiate device damage. However, latent defects are extremely difficult to prove or detect using current technology, especially after the device is assembled into a finished product.
Static Electricity - Electrostatic Discharge (ESD)
"Most books or articles indicate that a spark can't be seen until the voltage on your body reaches between 450 to 750 VDC. Others indicate that they are very hard to notice until it reaches 1000 VDC. For most people, to feel a shock from a static electricity discharge the voltage is between 2,000-4,000V. A 0.5mm arch of static electricity carries approximately 2850V."
Semiconductor Electromigration In-Depth
Ground that mat, wriststrap and if possible humidify the environment
when handling components, avoid touching any chips, circuitry and the slot contact fingers, hold PCB boards by the edges wherever possible
--------------------------------------------------------------------------------------------------------
ESD Susceptibility Analysis
"ESD votages sufficient to damage semiconductor devices are often lower than the threshold of human sensory perception, making a person unaware that a static discharge has taken place"
thats the basic proceedure most employ, its best if you do that like every other move, and be aware of exactly how much RH (Relative Humidity) influences Static Discharge
Taking great care to never touch any chip or lead, handling only the PCB, perferably by the edges.
the other point of my post is that while the immediate cause and effect relationship of catastrophic failure, using the "typical" proceedure is low...
This board is filled every day with people who have developed RAM errors, data corruption problems (generally RAM) ect, Most of which can be traced to either poor power regulation (Transient Response) of the PSU, or ESD
Latent defects caused by ESD in any IC (and they are just everywhere from HDDs to NIC, CPU, RAM ect) are massively underated as a cause of problems. If you have eliminated power fluctuation problems (PSU voltage regulation and power conditioning) and still experience a component failure, odds are that it was a latent defect, either from installation, or one that wasnt caught during manufacturing.
the membership displays a cavalier attitude towards this issue for 2 reasons, RMA's are pretty easy, and they rarely employ the same component for its fully rated lifespan, upgrading before the eventual premature failure becomes appearent.
But
a latent defect, not only effects the lifespan, it degrades the performance of the IC as well, and is often the difference between the "Golden Chip" benchmark leader, the norm, and "why cant I get the same OC as this guy? Ive got the same components"
and since im now the mod of Power supplies...
It is a power issue, more or less, its certainly related
first up
ESD Precautions and Practices
The ATX motherboard specification maintains +5VSB power to the motherboard
unlike PC/XT, AT, Baby AT and LPX form factors that employed a manual switch to turn on the power to the motherboard, the ATX form factor employs a "soft power" scheme
allowing software control of power, allowing the OS or other ap to turn the computer off, it also allows wake on LAN or Wake on WAN. Since there is a low level of power supplied to the board at all times, you need to address this whenever your swapping out components
the ideal solution is to unplug the power supply from the socket then ground the case with an alligator clip to a seperate ground point and use a wristrap to ground you
the alternative method is to turn off the PSU with its own switch
reliable only if the board has a 5VSB LED indicator on it
at which point you know the board is unpowered, yet the case is still grounded via the AC Socket
the alternative method if there is no switch on the PSU and LED mobo power indicator is to unplug the PSU from the wall socket, then disconnect the main power connector and plug the PSU back into the AC Socket, where once again you have the case grounded
keep in mind that typically the PSU physically contacts the case with a metal to metal contact, at least in the past, and would have at least some contact via the screws, but these adys with painted cases and supplies, some augment that with a grounding strap for the PSU itself (very typical in server supplies where they take no chances with contact)
and religously touch a bare metal surface in the case to ground yourself when swapping componets (this is very typical in here with enthusiasts)
but all in all wristraps are cheap and so are alligator clips and a bit o wire
a grounded work pad is also a good investment, as is being aware of how large a role the lack of humidity has in ESD events, especially in Winter when hot air heating desiccates the moisture out of the air
(see I live on the Rocky Mountain High Dessert Plateau, where its already dry and in Winter with central home heating I humidify the environment when working on components)
ESD Reference
http://www.ewh.ieee.org/r10/bombay/news2/story11.htm
"According to (not so) recent studies conducted by the AT & T Bell labs, 25 % of all component failures today are related to E.S.D and out of all defective components that arrive 50%are damaged by E.S.D. the annual damage due to these failures is estimated at 25 Billion dollars"
An Integrated Circuit (IC) consists of several transistors fabricated on one chip. Due to the advances in L.S.I and V.L.S.I thousands of transistors are crowded on a single chip. By decreasing the thickness of the gate oxides and interconnecting lines the manufacturers hope to achieve much higher speeds at very low power consumption. But under these conditions if the Electrostatic Discharge passes through an IC and the current that results is not diverted or diminished by a suitable protective mechanism, the discharge may raise the temperature of the junction inside the component to melting point which will cause damage to the junction or interconnecting lines. Since surface mount devices are smaller than conventional ICs they are even more susceptible to E.S.D damage. E.S.D causes two main types of failures: -
1. Immediate failure where the effect can be readily seen by the equipment manufacturer.
2. Delayed failure where the device is damaged only upto the point where it may pass quality control tests, but wears out sooner than its rated time
http://www.esda.org/esdbasics1.htm
Table 2
Examples of Static Generation
Typical Voltage Levels
Means of Generation .........10-25% RH ......65-90% RH
Walking across carpet ......,35,000V ...........1,500V
Walking across vinyl tile ....12,000V ............250V
Worker at bench ................6,000V .............100V
Chair with urethane foam ..18,000V ...........1,500V
ESD DamageHow Devices Fail
Electrostatic damage to electronic devices can occur at any point from manufacture to field service. Damage results from handling the devices in uncontrolled surroundings or when poor ESD control practices are used. Generally damage is classified as either a catastrophic failure or a latent defect.
Catastrophic Failure
When an electronic device is exposed to an ESD event it may no longer function. The ESD event may have caused a metal melt, junction breakdown, or oxide failure. The device's circuitry is permanently damaged causing the device fail. Such failures usually can be detected when the device is tested before shipment. If the ESD event occurs after test, the damage will go undetected until the device fails in operation.
Latent Defect
A latent defect, on the other hand, is more difficult to identify. A device that is exposed to an ESD event may be partially degraded, yet continue to perform its intended function. However, the operating life of the device may be reduced dramatically. A product or system incorporating devices with latent defects may experience premature failure after the user places them in service. Such failures are usually costly to repair and in some applications may create personnel hazards.
It is relatively easy with the proper equipment to confirm that a device has experienced catastrophic failure. Basic performance tests will substantiate device damage. However, latent defects are extremely difficult to prove or detect using current technology, especially after the device is assembled into a finished product.
Static Electricity - Electrostatic Discharge (ESD)
"Most books or articles indicate that a spark can't be seen until the voltage on your body reaches between 450 to 750 VDC. Others indicate that they are very hard to notice until it reaches 1000 VDC. For most people, to feel a shock from a static electricity discharge the voltage is between 2,000-4,000V. A 0.5mm arch of static electricity carries approximately 2850V."
Semiconductor Electromigration In-Depth
Ground that mat, wriststrap and if possible humidify the environment
when handling components, avoid touching any chips, circuitry and the slot contact fingers, hold PCB boards by the edges wherever possible
--------------------------------------------------------------------------------------------------------
ESD Susceptibility Analysis
"ESD votages sufficient to damage semiconductor devices are often lower than the threshold of human sensory perception, making a person unaware that a static discharge has taken place"
thats the basic proceedure most employ, its best if you do that like every other move, and be aware of exactly how much RH (Relative Humidity) influences Static Discharge
Taking great care to never touch any chip or lead, handling only the PCB, perferably by the edges.
the other point of my post is that while the immediate cause and effect relationship of catastrophic failure, using the "typical" proceedure is low...
This board is filled every day with people who have developed RAM errors, data corruption problems (generally RAM) ect, Most of which can be traced to either poor power regulation (Transient Response) of the PSU, or ESD
Latent defects caused by ESD in any IC (and they are just everywhere from HDDs to NIC, CPU, RAM ect) are massively underated as a cause of problems. If you have eliminated power fluctuation problems (PSU voltage regulation and power conditioning) and still experience a component failure, odds are that it was a latent defect, either from installation, or one that wasnt caught during manufacturing.
the membership displays a cavalier attitude towards this issue for 2 reasons, RMA's are pretty easy, and they rarely employ the same component for its fully rated lifespan, upgrading before the eventual premature failure becomes appearent.
But
a latent defect, not only effects the lifespan, it degrades the performance of the IC as well, and is often the difference between the "Golden Chip" benchmark leader, the norm, and "why cant I get the same OC as this guy? Ive got the same components"
