【 Weak current College 】 portables repair ideas

1. first of all, first check that the power adapter is no voltage output, if any, and then check the generated 12V, 5V, 3. 3V power supply chips have no reference voltage and standby voltage 5V, there is also a battery charger has no power supply, CPU power supply circuits have 3. 3V power supply, there is no reference voltage, power management chip side through the FET gate drive of high and low is no power supply, it is not according to the preparation of standby, check the do not have insurance resistance have bad, there is no filter capacitor is bad!

2. you this, battery charging and dissatisfaction with the electricity, but the battery is OK is good, is most likely that the following conditions for reference:
1. early termination of the charging circuit
2. the FET and boosting capacitor damage
3. chip internal control parameters cause gone bad, can only be the chip a
If the discharge does not charge, boosting capacitor and FET are not bad, only for chip. General chip is not easily broken.. 、

3. not post,
A look at the second hearing three detection. First, if there is no obvious visible faults. If there is no place to burn, deformation, crack, etc. There is no place to smell the burning in the paste. 2. power on and listen to have normal or abnormal sounds, and from there. III. testing in the absence of specialized tool can be used only by multimeter test whether insurance resistance, there is no obvious the blowing of the short circuit, etc. CPU, memory is not a good exposure can test. Note the power not to short circuit and damage.

4. screen display is not working properly
From the fault seems likely a screen or pingxian issues: one, check the motherboard power supply on the screen correctly, voltage 1 point v, 2 a few volts, 3-point a few volts. IBM machines because of the high pressure plate and power supply are on the LCD screen to the same data cable, so there are several groups of 5 point v, 10 v voltage, around and of course the 0 Volt is ground! 2, if there is a power supply, check the screen next to the Harbor Department, multimeter continue in voltage. Voltage values above! if there is no voltage is certainly pingxian failure. Changing a pingxian or use the same voltage line take-up a pingxian can, if you can you can troubleshoot. If you still fail to exist, the screen may have a fault, this situation rarely, very rarely exist!!! Determine the screen voltage normal, to repair the screen. In the screen block on micro-signal chip because there is no circuit diagrams, so not sure every foot of operating voltage. Can only be used to see this chip processing an oscilloscope since the waveform is correct, the two go (a) if not, replace the same model and the chip can block. If you hop, check the surrounding of capacitance. 2 if not, just swap block screen because the screen voltage cable is loose. Third, if there is no power supply, check the video output voltage stability, this part of the voltage is a processing chip, and then outputs the signal to pingxian. If voltage is normal, it can determine whether this chip failure. In exchange for the same model chip can have voltage output to pingxian, then you can go with part II of the same check.

5. first check the motherboard does not power on, have your power management chip 1631 1632 or (most are both chip) of the fifth toe has 5 v, 21, 22 feet have 16 Volt and 5 volt. To see if the 8-legged 2951 movies test he have 5 volts

6. do not post the inspection method:
1. exclude the power outlet, the module is loose access to undesirable, the appearance on the motherboard, cpu loosening. virtual welding and other phenomena.
2. check the main power supply fuse, is burned, if burned, to fight resistance values, which can not be too small or short response can be ignored! (Exclude isolated circuit failures to enter the next step)
3. measurement, 3.3v/5v generate circuit/cpu main supply circuit/battery charging circuit, there is no supply voltage = adapter voltage without the maintenance of the corresponding circuit .3. power button, is end-start with no 3.5-5V,-5v checking 3.3v/circuit, generally have the circuit. (3.3v/5v generate circuit judge should be no drawings we use reverse method to determine which of the circuit on the motherboard is 3.3v/5v circuit first locate the memory sockets nearby SMD capacitor obviously (circuit board capacitance 95% are used to filter) is attached to one end and to the other end is then 3.3v/5v generate circuit output inductor on intermediate insurance resistance can also be used PS/2 mouse port power supply 5v to judge 3.3v/5v generate circuit (power circuit your notebook features are characteristic: they were the one inductor 2 MOS (8 feet of field effect 3 pole tube) and power supply modules (collectively referred to as a function of the different sub cpu main voltage battery charging 3.3v/5v generate circuit three circuit structure is similar to using the reverse method to distinguish between what is and what power supply circuit cpu main cpu near SMD capacitor has many p2 above cpu generally use 3 supply main electrical kernel outer core to differentiate which is the main power filter capacitor is also very simple and most numerous are the main characteristics of electric filter capacitor capacitance is attached to the positive and negative with negative capacitance which set of parallel number up to which the group is found in the main cpu power allows for electricity generation circuit cpu main battery charging circuit used batteries allows 3.3v/5v generate circuit above mentioned) press the power button should produce 3.3v/5v/cpu voltage, such as the main electricity without also allows bad which repair which!
4. power supply to normal, it is necessary to look at the clock circuit has no power supply, 686 machines usually have two electricity 3.3v2.5 from 3.3v/5v generate circuit and cpu outer core voltage) circuit, the test point find edge SMD capacitor.
5. comparative headache does not reset circuit chip data is not very hard to find with the hard disk of the PC card slot of the Reset PIN (don't tell me you don't know is which!) Simple judgement.
6. BasicThat power clock reset correctly, we will refresh the BIOS notes high-grade machine brush bios must avoid avoid to be backed up, Oh.