Allan_01 :
Just wan't to know that
will i expect a defective HW(MOBO,RAM,MEM,HDD,PSU)
during the build
Or its just small chance
WHAT will I do if I encounter defective parts?
Defective parts depend mostly on two things:
1) How tight is your budget?
2) How well did you research your parts?
It's possible to predict (with better accuracy than most would realize) what kind of build experience a person is in for, based on how much they are willing to spend and (more importantly) how much TIME and effort they are willing to invest, before purchasing a single piece of hardware.
That doesn't mean you have to spend thousands of dollars and weeks on reading reviews. But either or both will help.
Most common problem (always) is skimping on the power supply. If you buy a power supply included with a case, OR spend less than about $75 USD on the PSU alone, you've just doubled (or more) your odds of not being happy on build day. If you go along with "conventional" advice to just buy "brand X", same problem. There are some brands that (although widely recommended) rarely put out really good units. If in doubt though, you can always go Seasonic. It's really tough to mess up choosing Seasonic.
Other common build problems in order of frequency:
1) Buying RAM that is too fast for the motherboard, so the system will not boot properly. I see this one on almost every Intel build. Example...you will see a motherboard that specifies a range of frequencies of DDR3 RAM that goes up to like 2000, but everything past 1333 has a * on it (OC). That means the RAM will work if you input the timings manually. But in order to do that, you have to access the BIOS first. To access the BIOS, you need compatible RAM. I can't count the number of posts I've responded to (elsewhere) where someone bought 1600 DDR3 RAM (for example) for an Intel build with a 1333 motherboard, and now wonder why the system won't boot...
On a side note, AMD builds have fewer issues with RAM as AMD chipsets support faster RAM anyway...
2) Using a 4-pin CPU power cable on an 8-pin motherboard CPU power connector. This error (and it is an error) is made worse by motherboard manufacturers who incorrectly state that it will work. It almost never does. Consequently, the documentation is misleading.
Actual DEFECTIVE (from the factory) or DOA components are somewhat rare. But if you read reviews (like on newegg in particular) you would conclude that DOA is a lot more common than it is. What happens is, someone will make a mistake like number (1 or 2) above, and then post that their motherboard is DOA. Ummmm, no. That is builder error.
The most common DOA components are power supply (90%) and motherboard (8%) with everything else combined making up the other 2%. If you want to be happy on build day therefore:
1) Get a really high-end power supply. READ REVIEWS to choose it!
2) Stick to quality motherboards like Gigabyte ultra durable or Biostar T Series*
3) Triple-check your RAM specs to make sure that they are compatible with your motherboard. Stick to name-brand RAM with decent heatsinks and low CAS ratings.
If you cover those three items, you've just reduced the odds of a DOA build by probably 99% or better.
* I know Biostar doesn't have the greatest rep, but their T Series boards are truly high-end and perform extremely well, not just at initial build...but long-term reliable.