Laptop No boot overhaul method

First, there are problems:

Because the work is busy, my T21 has two days useless, unexpectedly has the malfunction, the point is not bright. Before the problem is normal shutdown, has been used well.

Second, the specific failure:

When the boot, the hard drive lights only flash, nothing else reflected.

Connect the AC power supply, Power indicator lantern light, press the power switch on the boot of the hard drive light is no response, press and hold the power LED will not light for a few seconds, and then light, but the hard drive indicator will not be lit, can not open the machine. After a period of time can be turned on, starting a few days as long as can be turned on, can be used normally. Later, power off after the boot (performance for normal use, suddenly power off, installed on the battery is the same).

Third, find the cause of the failure

To get my little black back to health, I consulted a lot of XD, answer what all have, in order to diagnose, not be JS slaughter, had to crazy in the online search, unexpectedly was I find two websites have posts and my situation, are the motherboard power management chip failure. And my little black appearance, is T20, T21, T22 series of common problems, are the motherboard on the power management chip ADP3421 and ADP3410 failure, resulting in no boot. The general situation is ADP3421 more problems. Then consulted the hope boss, also said the motherboard power management chip problem.

Iv. Maintenance

1, first to find js,js must be small black left detection, let me the next day to fetch, did not dare to put it in his, had to bring back.

2, and to find the blue fast person, he suggested I sent to Urumqi to detect, I asked how much money, he said less than 500, more than 1000 a little, I had to bring back the little black.

3, no way, had to do it himself, because the small black bought has been very healthy, so also did not dismantle, want to dismantle do not know from that hand, fortunately specialized network homepage has T21 hardware maintenance manual, hurriedly downloaded a copy, print out. Careful study, in accordance with the maintenance manual of the dismantling process, the main version taken down, found the power management chip ADP3421, than I imagined a lot smaller. The difficulty of their own, one is too small parts, the second is no special tools hot air torch. I think of a mobile work friend, is the director of the Business department, very beautiful mm, they have a special repair phone maintenance department. Find Mm,mm said no problem, bring it over.

4, I immediately contacted a businessman in Shenzhen, he said that there is a power management chip. Hit the past 300 yuan (Chip 280, EMS20).

5, four days later, received the Shenzhen mail to the power management chip, hurriedly and small black removed, the motherboard to take down. Find mm, in the maintenance of mobile phone place, repair master with hot air torch to the motherboard power management chip down, change. With uneasy mood, go home, put small black outfit good, boot ...

Hey hei my little black finally restored to health.

After this incident, I found that there are tools and chips, I can handle.

The following picture is the ADP3421 from my motherboard

The use of notebooks will inevitably encounter a variety of problems, such as the screen is not bright, frequent crash, do not boot and so on. In the face of difficulties, there is no difficulty in manufacturing difficulties are also on the principle, today, I am not a rookie for everyone to hand out a notebook does not boot maintenance law martial arts cheats. To all the friends who love to solve the problem of common research!

Check whether the power outlet is normal, each module is loose or bad contact, there is no attachment on the motherboard, the CPU is not loose. Virtual welding and other phenomena.

Check the main power supply fuse, is not burned, if burned, to hit the resistance value, can not be too small!

Measuring 3.3v/5v generation circuit/CPU Main power supply circuit/battery charging circuit, see if there is no power supply voltage if not, overhaul the corresponding circuit.

Power Start button, there is no 3.5-5v voltage, if not on the check. 3.3V/5V circuits generally have this circuit generated. Because there are no drawings, we use the reverse method to determine which circuit on the motherboard is producing the 3.3v/5v circuit. First find the memory slot near the SMD capacitor, it is obvious (circuit board capacitance 95% are used to filter) one end and the other end of the 3.3v/5v circuit output inductance, the middle has the insurance resistance can also use PS/2 mouse mouth power supply 5v to judge 3.3v/5v generation circuit. The power supply circuit of notebook has characteristic: all have 1 inductance, 2 mos tube (8 feet of the field Effect 3 polar tube) and power modules, according to the role of the main CPU voltage, battery charging, 3.3v/5v generation circuit, the 3 circuit structure is very similar, with the reverse method can be used to distinguish which is what circuit.

CPU main power supply, CPU near the chip capacitor there are many, now the CPU generally uses 3 power supply, main electric, core, external core, to distinguish which is the main power of the filter capacitor is also very simple, the largest number is the main electric filter capacitor. Features: These capacitors are connected with positive, negative and negative, which group of the number of parallel capacitors, which group is the main CPU power. To find the main power generation of CPU circuit, battery charging circuit, with the battery cathode to find the 3.3v/5v generation circuit (said above). Press the power button should produce 3.3V/5V/CPU main electric voltage, if not also follow, bad where to fix. Ha ha!

The power supply is normal, it is necessary to see whether the clock circuit power. Now the machine generally has 2 power supply, 3.3V 2.5 respectively from the 3.3v/5v generation circuit and the CPU external nuclear pressure generation) circuit. Find the side of the chip capacitor for testing.

Reset circuit is more headache, no chip data is not very easy to use, the PC Card slot with the reset foot (don't tell me you don't know which!!!) A simple judgment.