SMT spare parts, such as SMT nozzle, SMT feeder, SMT feeder parts, SMT filter, SMT cutter, SMT consumbles, (2)

How to analyze common failure case of reflow soldering

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              A common fault handling of reflow soldering is analysed

Reflow soldering heat alarm prompt temperature difference is too big or too small, in the process of computer tip ‘communication failure can’t start the machine, according to the two kind of phenomena, we had a lot of test and analysis work, draw the following conclusions:

1, in the process of reflow soldering heat suddenly alarm prompt “temperature range of a certain temperature too low or a certain temperature and set temperature difference is too large”.
Aiming at this phenomenon, we can preliminary judgment fault will occur in the heating or part overheating protection, and so will all overheat protection switch sub let its failure, and start the machine, found that seems to be normal.After further analysis, under the condition of the overheating protection switch sub machine can work, but in the event of heating, the temperature rise too high a less protection of defense, will bring more serious consequences.In order to solve this problem, we must put 16 from heating unit to find out one or several thermal protection switch failure, we will each heating unit with this problem apart, examine its overheating protection switch, found problems the second heating unit overheating protection switch, with a moving contact bimetallic strip fixed weak, cause the moving contact and the static contact point contact is not good, or not at all contact (normally two contacts should be contact together and conduction).Because there is no the second heating unit of the spare parts to replace we will switch sub to ensure production run smoothly.To this can solve the problem, but as soon as possible to the broken overheating protection switch is off, so as to achieve the purpose of protecting the second heating unit.

2, if the downtime is longer, when it turns switched on again reflow computer tip ‘communication failure and can’t start the machine for a long time to let the heat.
Aiming at this phenomenon, we preliminary suspect as the communication line fault, then replaced the telecommunication lines, the question remains, so denied this conjecture.After further observed, when the communication is not successful, the lights on the status of the controller is not normal, orange lights should be flashing, and should not go out.Based on manual measuring line 1001 and line voltage between 1007 found that the voltage is not constant for the + 5 VDC, about + 2 VDC when communication is not successful, the problem is out of here, why the voltage is too low, the original control panel in the end of the machine here are two simulated load resistance, resistance ought to be ‘5’R , but actual value only two ‘2’R, but I have measured the value to change it into ‘5’ R problem is resolved.

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