1: Check the parts

Quality inspector to inspect the appearance of the parts (1, visual inspection of the equipment whether the parts are deformed, discolored, damaged, burned, whether the filament is bright after power). These problems are often the cause of the impact of the touch screen to determine the causes associated with the failure, and then repair the touch screen.

2: Poor contact

Insulator energized or not, manual knocking or pressing method is an effective repair method for poor contact caused by failure, easy to find false solder, poor contact and other problems.

3: Replacement of components

When a component is not sure if it is good or bad, it can be replaced and replaced with a good part. If the troubleshooting proves that the original component is faulty, for individual components that are not convenient to measure, replacement is the most time-saving and fastest repair method!

4: Current test

Test current for the repair of one of the touch screen current: mainly used to measure the load current and operating current of the transistor and integrated circuit block, detect the load of the integrated circuit, transistor / integrated power supply is normal, etc.. As long as the measured star current is normal, you can conclude that the touch screen circuit is basically normal. However, during the measurement, the current differs greatly from the normal value, indicating that there must be a problem with the current. You can analyze the cause of the problem, and then check.

5: Water inlet failure detection

(1) Prepare the disassembly tools.

(2) Make your own resistance measurement probe. Remove the machine, look at the touch screen transparent with small water marks, the amount of water is small touch screen cable four-wire resistance (2k file) flushed to the left, start counting. Found that 12, 23, 34, 14 have resistance values (generally 13, 24 have resistance values, 14, 23 should not have resistance values, no contact state). Therefore, the judgment is an internal short circuit.

(3) Handling touch screen it moved with a small screwdriver for a week, but there is no gap into the line, so use a hobby knife to slowly cut in the corner, remember the glass layer along the bottom. After prying, use the hot air of the hair dryer for about 10 seconds, listen to the recording, and then blow again. When the prying device is in a hot state, press it down and join, then use a multimeter to measure the resistance of the four lines (13 and 24 resistance values of 290 ohms and 240 ohms, respectively) touch screen repair.

(4) Along the edge with a silicone rubber seal dry, install the surface shell (double-sided adhesive bonding), installation, testing, touch screen correction, all normal.