Parts, Is It What It Says It Is?

In the past electronics repair was a pretty straight forward business. Find the bad part and replace it. You did not have to worry much about the parts you were getting. You could count on their quality even from places like Radio Shack. Now days that is just not true. If you go to EBay for your parts you are never really sure what you are getting. Is the part you ordered actually what you will receive? Is it actually what it is marked to be. Even if you buy from reputable sources there can sometimes be problems with the parts. Look at the rash of bad capacitors we had a few years back. Some companies were selling caps that they knew were not up to snuff and those caps found their way into a whole lot of consumer equipment and we are still paying the price for it today in the form of dead monitors, flaming power supplies and many other devices. Technicians know that it is a good idea to test all parts before you install them but some parts require a specialized piece of equipment to test properly. In the case of capacitors it is actually several pieces of equipment. A capacitance meter, an ESR meter and a leakage meter. Most techs do not have all of these testers on hand.

The problem even falls over into other parts. Take resistors for instance. I have found that cheap resistors from China do not seem to care what the rated tolerance is. Most of them seem to be between 10% and 20%, sometimes higher.

ICs are another big problem these days. I have gotten ICs that are sold as one thing but inside are either something else all together or defective. I don’t understand this really. How much profit can there be in etching off a part number and stamping a new number on it. It seems like a lot of work for a small gain. Sometimes they are actually what they say they are but; I have 200 TL072 op-amps that must have been the rejects pulled out of the trash because none of them meet specs. However I only paid $2 for the whole lot so I guess I should have known. Too good to be true and all.

The lesson here is, don’t be surprised if the overseas parts do not live up to your expectations. Test all parts to the best of your ability before you put them into service. Buy name brand parts if the unit you are repairing is for a customer or work. If your experimental widget does not work as advertised no big loss but if the mission critical device in your audio chain for air at the radio station fails, big problem.