Quick Answers
Water damage can cause a touch screen to become unresponsive in a few different ways:
– Water can short circuit the digitizer, which is the layer that senses touch. This will prevent the device from detecting finger inputs.
– Liquid can corrode contacts on the touch screen or logic board, interrupting the electrical paths needed for the touch screen to function.
– Moisture in the screen can interfere with capacitive sensing, preventing the screen from properly registering touches.
The good news is that with the right repairs, an unresponsive touch screen caused by water damage can often be fixed. Here are some quick solutions:
– Open the device and dry out all internal components. Remove any corrosion and wash contacts with isopropyl alcohol.
– Replace damaged flex cables or touch IC chips on the logic board if corrosion is present.
– If the digitizer is damaged beyond repair, the entire touch screen assembly may need replacement.
– For moisture in the display, disassemble and dry out the screen or replace the LCD panel.
With proper troubleshooting and component-level repair, an unresponsive touchscreen can usually be restored to full working order after water damage.
Assessing the Damage
When a touch screen stops responding after water damage, the first step is to thoroughly assess the situation to determine why it is no longer working. Here are some key things to check:
– Visually inspect the screen for any cues. Look for condensation under the glass, visible moisture, fogginess, or distorted graphics. This indicates water has infiltrated the LCD panel and gotten inside the display.
– Check if the touch screen is still partially responsive. Are some areas still accepting touch, while others don’t respond? Partial or intermittent responsiveness points to a connection issue.
– Test with an external display. If touch works on a connected monitor, the underlying system is likely OK and the problem is isolated to the touch screen assembly.
– Consider when issues arose. Did the touch screen stop working immediately after a spill occurs, or some time later? The timing provides clues as to where moisture may have spread.
– Inspect flex cables, connectors, and touch controller chips for any signs of corrosion. Green or white buildup indicates corrosion from liquid damage.
Thoroughly examining the device both externally and internally will help pinpoint what component(s) have been affected by water exposure. This critical first step will guide effective troubleshooting.
Checking for Physical Damage
Physically examine the touch screen for any external signs of water damage:
– Is the display distorted, blurred, or discolored? This indicates the LCD panel has been damaged.
– Do you see moisture or condensation under the glass? The screen will need to be disassembled to dry it out.
– Are there any noticeable cracks in the glass or bezel? Damage may allow moisture ingress.
– Take note of any corrosion on flex cables or logic board connectors. Green corrosion deposits point to liquid exposure.
Identifying physical damage provides visible evidence that water has reached internal components, giving clear direction on where to focus repair efforts.
Testing Digitizer Responsiveness
The digitizer is the touch-sensitive layer that registers finger inputs on the screen. Here are some ways to test if the digitizer is still functioning:
– Try touch gestures in different areas of the screen. Do some sections still respond? Partial functionality suggests a connection problem.
– Use a stylus or pen to tap on the screen. This tests if delicate touches are still detected.
– Install a touchscreen tester app and run diagnostics. This will check for digitizer damage or calibration issues.
– Connect an external display. If touch works on the secondary screen, the underlying touch hardware is likely okay.
Isolating digitizer operation gives important clues whether replacement is needed, or if there are intact parts that can be recovered.
Drying Out Internal Components
If moisture has gotten inside the device, thoroughly drying internal components is crucial before applying power:
– Disassemble the device down the the logic board. Remove batteries and modules.
– Use compressed air to blow out any droplets of water and displace residual moisture.
– Let the logic board and internal parts dry out for at least 24-48 hours before reassembly. Air drying is safest.
– Check for any sticky residue left behind after the water evaporates. Carefully clean with isopropyl alcohol and a toothbrush.
– Inspect the logic board and flex cables for corrosion. Use isopropyl alcohol and gentle abrasion to remove it.
– Cover any corrosion-prone chips or connectors with dielectric grease when re-assembling. This prevents future corrosion.
Allowing ample time for drying prevents short circuits and further corrosion when power is restored. Be thorough and patient for best results.
Removing Corrosion
Water damage can cause light green or white corrosion deposits on logic board components. Here’s how to safely remove it:
– Lightly brush chips and contacts with a soft toothbrush dipped in isopropyl alcohol. Slowly dissolve and loosen corrosion buildup.
– For stubborn deposits, apply a small amount of flux remover or electronic contact cleaner. Let it sit for 30 seconds before scrubbing.
– Avoid harsh scrubbing. Work patiently to dissolve corrosion and limit abrasion to fragile chips or traces.
– Dry thoroughly and coat cleaned area with dielectric grease when done. This prevents future corrosion.
– If corrosion is severe enough that it has eaten through metal traces, professional microsoldering repair may be required.
With care and the proper solvents, corrosion can often be removed to restore damaged connections and components.
Replacing Damaged Flex Cables
If water exposure has caused corrosion on flex cables that connect the touch screen to the logic board, replacement is often required:
– On iPhones, carefully disconnect the touch flex cables from the logic board. Note orientation for reassembly.
– For less corrosion, clean flex cable contacts thoroughly with isopropyl alcohol and a soft bristle brush.
– If corrosion has damaged flex cable traces, purchase a replacement online from a reputable source.
– Carefully detach the old flex cable from the screen side, and install the new one in the proper orientation.
– Reconnect to the logic board, taking care to align pins properly. Avoid bending or twisting the cable.
– Secure cables to avoid strain on solder points. Heat shrink tubing can help strengthen connections.
Flex cable replacement restores the vital data pathways between the touch screen and main logic board components.
iPad Digitizer and LCD Flex Cable Replacement
On iPads, the digitizer and LCD panel connect to the logic board via a single cable. If it’s corroded:
– Use a plastic spudger to detach the adhesive securing the display cable at the bottom of the iPad.
– Disconnect the flex cable where it attaches to the logic board. Note orientation.
– Install a replacement LCD/digitizer flex cable in the proper direction. Press firmly for a secure connection.
– Cover any exposed metal with Kapton tape to prevent shorts if metal is exposed.
– Replace the adhesive and re-secure the display cable at the edge of the frame upon reassembly.
Careful installation avoids further damage and restores the data link between the screen and internal components.
Replacing a Faulty Touch IC
On some devices like iPhones, the touch input controller is a dedicated chip on the logic board. If faulty due to liquid damage, replacement is required:
Identifying the Touch IC
– The touch IC is located near the display connector on the logic board. It has a label such as “Touch IC” or a codename like “Cypress” or “ButtonBoard”.
– On iPhone X and newer, the Touch IC is integrated into the display connector as a long thin chip labeled “Touch Flex Logic”.
Removal and Replacement
– Use a heat gun or hot air station to uniformly heat the chip to approximately 100°C to soften solder joints.
– Use a quality soldering iron to fully desolder all pins. Avoid excess heat.
– Thoroughly clean the solder joints with solder wick. Apply flux to aid cleaning.
– Align the replacement chip and carefully resolder each pin. Maintain even heating.
– Inspect for any shorts or leftover solder residue when complete. Use magnification if needed.
Properly desoldering and replacing a damaged touch input chip restores touch functionality after water damage.
Replacing the Touch Screen Digitizer
If diagnostic testing confirms the digitizer layer is non-responsive and damaged, replacement of the entire touch screen assembly will be required:
Assessing Digitizer Damage
– Visually check for cracked glass, distorted graphics, or dark patches indicating internal damage.
– Run a touchscreen diagnostic app to check for lack of response to stylus inputs across entire screen.
– Connect an external display to isolate digitizer damage from other components.
Installing a Replacement Digitizer
– Purchase a replacement digitizer assembly with LCD display from a reputable supplier. Avoid low-quality aftermarket parts.
– Follow step-by-step guides to fully disassemble the device down the the screen. Note screws and connectors.
– Disconnect and remove old display assembly. Transfer any intact components like the earpiece and home button.
– Connect new digitizer/LCD assembly. Be careful aligning connectors. Reassemble device carefully.
– Upon first boot, run diagnostics again to verify full touch functionality. Recalibrate if needed.
While labor-intensive, digitizer replacement is often the only option after extensive physical damage from water exposure.
Cleaning and Drying the LCD Panel
If moisture is clearly visible within the LCD panel, disassembly and cleaning will be required:
Opening the Display
– Follow disassembly guides to carefully separate the glass lens, digitizer layer, and LCD panel.
– Some devices have the glass and digitizer fused, requiring them to be replaced together.
– Keep track of any small screws and brackets between layers. Note orientation for reassembly.
Cleaning the LCD
– If there is standing water visible, lightly shake the panel to displace it before wiping dry with a microfiber cloth.
– For foggy or cloudy areas, carefully wipe the polarizer film covering the LCD using distilled water and a lint-free cloth.
– Allow to fully dry before reassembly. Any moisture left inside will lead to distorted graphics and touch issues.
Re-sealing the Display
– Replace any worn gaskets or adhesive strips around the panel with new pre-cut ones.
– Apply fresh adhesive to any areas where layers previously bonded, using minimal amounts.
– Reconnect flex cables properly and reinstall any brackets or screws removed during disassembly.
Disassembling and meticulously cleaning/drying an LCD panel can save it from water damage and expensive replacement. Just take care not to damage fragile ribbon cables.
Replacing the LCD Screen
For visible internal damage like distorted, flickering, or dead graphics, replacement of the LCD panel itself may be needed:
Obtaining Replacement LCD
– Purchase an LCD for your exact model from a reputable parts supplier. Avoid cheap generic panels which often have compatibility issues.
– For some devices, refurbished LCD assemblies are available at lower cost while providing high quality.
– Ensure any replacement includes needed components like flex cables and LED driver ICs.
Installation
– Follow step-by-step display removal guides for your particular device. Note screw locations and ribbon cable connections.
– Carefully disconnect and detach the old LCD panel once the display is fully disassembled down to the bare screen.
– Install the replacement LCD in the proper orientation, securing it into place with any removed brackets or screws.
– Inspect carefully for any misalignments before reassembly. Connect all flex cables properly.
– Confirm full touchscreen functionality upon first powering on the device after repair is complete.
While challenging, LCD replacement is very effective in restoring full visual and touch functionality after significant water incursion into the screen itself.
Conclusion
Water damage can disable a touch screen through shorts, corrosion, and moisture intrusion. But with diligent troubleshooting and component-level repair, full touch functionality can often be restored. The key steps include:
– Thoroughly drying out all internal electronics.
– Cleaning away any corrosion on logic board chips and contacts.
– Replacing damaged cables, connectors and ICs.
– Disassembling and cleaning moisture ingress within the LCD panel.
– Installing new LCD or full touch screen digitizer assemblies for non-repairable damage.
While labor intensive, touch screens disabled by water can usually be revived with a combination of drying, cleaning, and replacement of irreparable parts. With patience and care, you can get your touch screen working again without expensive whole device replacement.
