How to replace DMD Chip in a DLP Projector | Tutorial ft. Hisense 100L5F

Why the DMD chip may need replacing

The Hisense 100L5F uses a DMD chip containing thousands of microscopic mirrors that direct light through the projector and towards the lens. According to the tutorial, these mirrors can fail and create white square dead pixels across the projected image.

The video uses the Sharp RDMDPA040WJN2 DMD chip, identified as a 0.55 006 685 163 KGPH202X 230309f part. Pat notes that the general access method may also apply to similar DMD-based projectors, but the model and chip information should be checked before starting.

Important preparation and safety notes

If the projector is still under warranty, the video recommends contacting Hisense first. This repair should only be attempted after other options have been exhausted, as it involves removing the projector casing, motherboard assemblies and cooling hardware.

The projector should be unplugged before working on the motherboard. The tutorial warns that capacitors may still hold charge even when the device is switched off. A large Phillips-head screwdriver, a magnetic screwdriver, pliers and a plastic pry tool are used during the process.

Pat also recommends positioning the projector vertically where possible. This helps prevent the DMD chip from falling out during the repair.

Accessing the DMD assembly

The process begins by removing nine screws from the rear cover, followed by screws securing the top cover and additional screws underneath the projector. The cover can then be lifted after disconnecting the various plugs and cable clips. The connectors are different sizes, which helps with identifying their positions during reassembly, but the cables should still be handled gently.

After disconnecting the power connection, the metal plate and associated ribbon cables are removed. The DMD board is located beneath the area marked with a DMD arrow. Four ribbon cables are connected to this board, with two more positioned underneath.

To improve access, the tutorial removes the green motherboard and its L-shaped bracket from between the red and green boards. This requires removing screws and ribbon cables, including one cable in a less accessible position. The boards can then be moved aside while leaving some larger cables attached.

Removing and replacing the chip

The DMD cooler is held by four spring-loaded screws. Once the cooling plate is removed, four additional screws securing the DMD assembly can be taken out. The DMD board can then be lifted away, exposing the chip and its small plastic connector.

The replacement should be completed quickly to reduce the chance of dust entering the exposed area. The chip should not be touched on its front or central surface. It should be held by the sides and installed in the same orientation as the original part. A plastic pry tool can be used to position it gently.

Before reinstalling the cooler, excess heat paste should be cleaned away and fresh paste applied. The tutorial stresses removing both protective plastic areas so the chip does not overheat. Refit the plastic connector and holding plate, then tighten the spring-loaded screws gradually using opposite corners to distribute pressure.

Reassembly and testing

Reassembly follows the removal process in reverse. The motherboard is placed back onto its pins, cables and ribbons are reconnected, the metal cover is refitted, and the power connection and projector shroud are restored. The remaining rear and bottom screws are then installed.

After powering on the projector, the tutorial shows the Hisense logo and a projected image without the previous white dots. Pat also cautions that some sellers may supply a second-hand chip removed from another projector, which may have less remaining life. The video recommends seeking a new chip from a trusted seller.