Urgent customer's urgency, think what customers want,
Take the quality as the root, service for this
 Order Hotline： |
| 0755-85298917-606 |
Urgent customer's urgency, think what customers want,
Take the quality as the root, service for this
| Order Hotline： |
| 0755-85298917-606 |
Shenzhen wanchuangxing electronics co. LTD
Contact number:
0755-85298917-606（Sales department）
0755-85298917-602（The Marketing Department）
0755-66802023（Market line）
fax：0755-85298017
e-mail：szwcxpcb@163.com
24H Service telephone：
18028766818（Mr. Wu）
15999646351（Ms. Wu）
URL：Http://www.wcxpcb.com
address：Building 5, fuyong tong tailli industrial park, baoan district, shenzhen
How to repair the circuit board?
Usually the circuit board detection includes the following three levels of detection:
1) bare board detection;
2) online detection;
3) functional testing.
Using a common type of tester, a class of type and type of circuit board can be tested, can also be used for special application testing.
The same time as
The following through the online measurement method to explain how to repair the circuit board:
Step 1: Power on the board
In this step need to pay attention to is that some of the circuit board power is not a single, may need 5V, but also need plus or minus 12V, 24V, etc., do not put the power supply leakage circuit board power, through the hand touch the electronic Board components to see if there are hot parts, focus on checking the 74 series chips, if the components are hot case, then this component may have been damaged. After replacing the components, check that the board fault has been resolved.
The same time as
Step 2: Use the oscilloscope to measure the circuit on the circuit board to see if it is logical
If the output is not logical, need to be treated in two cases, one is the output should be low, the actual measurement is high, you can directly determine the chip damage; the other is the output should be high, The actual measurement is low, and can not determine the chip has been damaged, but also need to chip and the back of the circuit off, re-measurement, observation logic is reasonable to determine the chip is good or bad.
The same time as
Step 3: Use the oscilloscope to measure the crystal in the digital circuit to see if it has an output
If there is no output, you need to connect the chip with the crystal as far as possible after the removal of the measurement if there is no output, the initial determination of the crystal has been damaged; if the output, you need to take off a piece of chip back, Measure one, find out where the fault is.
The same time as
Step 4: Measure the bus with the oscilloscope to see if the signal is normal
With the bus structure of the digital circuit, generally including digital, address, control bus three. Use the oscilloscope to measure the three-way bus, compare the schematic diagram, observe the signal is normal, find out the problem.
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