Sometimes hard drives fail the motherboard that can usually be considered a great fault, if the course fee lifting. From experience: in case of failure of main Board surface itself is often in good condition.
The motherboard can be replaced in the presence of a donor for almost everything, even the processor if you wish high, but it's usually a pain in the ass, especially if the CPU BGA.
The rest of the chip without problems change. Basically, all the elements located on the circuit Board can be purchased separately, so you can use the cost of the donor and to pull out.
Consider a typical fault on the example circuit Board of the hard disk Samsung:
Begin to find fault with the continuity of the protective diodes(TVS Diod), set the multimeter to diode file transfer. TVS Diod shows resistance in one direction only, if it is burnt will show in short, simply put the multimeter will beep, unless you got the Chinese device.
In our case, after wypieki diode next to the capacitor(Capacitor) with the same excitement continued to squeak, and replacing the capacitor the short is gone, but hard still showed no signs of life.
Further prozvanivatsya diodes(TVS Diod) and throttle(Drossel) located near the whirlings(Driver), in our case not to be called an one of the chokes(the right call, for short, if burned not call). But replacing the throttle are also not revived hard disk.
Decided to look for a short circuit on. To search for needed regular laboratory power supply, a thermocouple or thermal imaging camera, or just too budget option in the form of paper(check with the store).
Connected Laboratory power supply to the SATA adapter, which one side is inserted into the hard drive and other connected laboratory power supply. Red test lead , Black.
Supplying power 0.5 A(amps) and 5V(Volts) almost immediately with a thermocouple it was found that in short is Twister(the controller), you can also squeeze a little of cheque and paper item that is strongly heated imprint.
The temperature knob almost immediately reached 45°C and continued to rise.
When short on Driver's power to be called an 22Ω(Ohms) channel a 5V(Volts) at 0.4 - 0.46 A(ampere), work driver 0.2 A(ampere)
Known as call one or the other element separately. But what if he is in the chain with something else, as it usually happens, how do we determine how true should show element with a basic knowledge of electronics?
The most simple and at the same time effective method of determining how to show a particular element to get the same serviceable hard drive and just to check with him.
One could even use the scheme, but as far as I know, to get the scheme to a hard disk often is not easy, but the same hard much easier, especially if you are engaged in repair of hard disks.