This is not necessarily the case, but one suspect would definitely be static-discharge while handling the components.
It is possible that handling the components introduced static electricity into the situation, and this can permanently damage your computer components. The simple act of unplugging a component can inject a static discharge into the electronics sufficient to cause damage. You probably won't feel a "zap", see a "spark", or hear a "crackle or pop", and you can't see any physical damage when ESD damage has occured.
Those damaged components then COULD cause damage to other components when installed in another machine. One failure can produce a cascade effect.
This problem with static electricity is generically called ESD (Electro-Static-Discharge) and failures can occur immediately or can be delayed by weeks or longer as discharge-weakened molecular structures finally breakdown.
ESD induced failures are most often permanent. ESD is a huge cost factor in the electronics industry, and manufacturers spend a lot of money on the equipment and training for ESD protection.
Some solid state components are now sensitive to damage by extremely low ESD...charge levels you can't even feel. You do NOT have to feel a "zap" to produce ESDs capable of damaging components.
Many components can be easily damaged by levels as low as several hundred volts, while some of the more sensitive solid-state components used in modern computers can be damaged by voltages lower than 20 volts under the right conditions...especially individual chips not yet installed in a circuit card.
Handling electronic components in a normal, dry environment (like the type of environment found inside during the winter with heaters going) can EASILY generate ESDs in excess of 20,000 volts. It's generated on your clothing, table tops, walking around on a carpet, packing materials, and so on. It can be carried through your fingers to the components.
I've personally measured charge build-ups of over 30,000 volts in less than 30 seconds on common printer paper in 5 to 10% relative-humidity environments. Plastic (e.g. projector transparencies) can be worse*.
Placing unprotected electronic components on common plastic table tops, paper, clothing, and other materials can cause permanent damage from ESD within millionths of a second.
Wiping components with a clean dry cloth can carry existing static charge as well as build-up new charge, and induce ESD into the components.
People planning to remove and install computer components need to learn and apply ESD protection protocols.
At a minimum, component handling should be performed using a properly set-up anti-static mat and anti-static wrist-band. There are also handling methods that should be used to ensure the best protection. Handling must be consistent as any breach of protocol places components at risk.
If you want to learn more about this, then do some Google-like searching on phrases like,
semi-conductor static damage
One webpage that has a very brief and easy-to-read informative bit on ESD is:
That page also points to additional ESD information resources if you want to learn more about it..
For example, the "Electrostatic Discharge Association" link provides a lot of information on ESD and how it impacts computers, users, and manufacturers in a presentation that ranges providing a basic overview to extremely technical details.
*You've probably seen that many electronic components come in plastic bags, and are surrounded by foam "peanuts". These are very special plastic bags, and the foam "peanuts" are often also special. They have either been rendered conductive, had a conductive metallic coating applied to them, or had an anti-static build-up chemical applied to them. It should be noted that over time, the anti-static property of such bags is degraded, with the topical chemically treated bags losing effectiveness earliest. Frequent handling of the bags causes the protection to degrade even faster. Thus, some ESD bags are not suitable for long-term storage of computer components. However, some vendors don't know or don't care about ESD packaging, and "protect" their shipments with untreated "peanuts", plastic "bubble-wrap", or even wadded-up paper.
It should be noted that opening the ESD protective bags on or near those "peanuts", bubble-wrap, or paper may immediately
damage your new adapter card. It may cause a "DOA", may instead cause latent damage that can cause a device to show no immediate symptoms but instead fail hours, days, or months in the future when it otherwise would have worked well for years.
Another good ESD information website for users and
Electrostatic Discharge Association website
It provides information on industry activity in this area, and a white paper in particular that may be of interest to HWA users. The paper provides information in a manner that ranges from basic overview to extremely technical. Some parts are directed mostly to manufacturers but contain some information some users may still find interesting or provide context to extent of the ESD problem and how it affects the computer industry/users.
"Fundamentals of Electrostatic Discharge" http://www.esda.org/esd_fundamentals.html
Part One--An Introduction to ESD http://www.esda.org/documents/fundamentalspart1.pdf
Part Two--Principles of ESD Control http://www.esda.org/documents/fundamentalspart2.pdf
Part Three--Basic ESD Control Procedures and Materials http://www.esda.org/documents/fundamentalspart3.pdf
Part Four--Training and Auditing http://www.esda.org/documents/fundamentalspart4.pdf
Part Five--Device Sensitivity and Testing http://www.esda.org/documents/fundamentalspart5.pdf
Part Six--ESD Standards http://www.esda.org/documents/fundamentalspart6.pdf
edited 200602160100uct to add "see ESD", "zap ESD", "hear ESD" comment with apologies to the rock opera..
edited 201404290500uct to call attention specifically to the link to the Electrostatic Discharge Association's .org website and one of the white papers.