Note: The electronic circuitry can be damaged by static electricity. Before touching or handling the circuit boards, touch some grounded metal parts inside the case, such as the copper foil shielding the combo jacks, or the metal body of the built-in mic assembly, or the gold-colored end of the 1/8" stereo minijack in the back of the mic assembly. Handle the circuit boards only by the edges, be careful not to scratch the wiring traces, and try not to touch the components or the traces.
Note: When you remove multiple screws in one disassembly step, as you remove each screw, immediately check to see if it is the same length and type as the other screws. If not, write down the differences and make a note which holes they came from. Some screws can seem similar but are of different lengths, and you must put them back in the right holes.
Tools needed (see photo below): Small phillips and slotted screwdrivers, needle-nose pliers (equivalent to "jewelers" tools). You MUST use high-quality tools of the proper size, otherwise you can strip the screw heads.
- Remove the battery compartment cover and remove the batteries.
- Remove the SD memory card.
- On the back of the unit, remove the three small rubber plugs from screw holes. Remove the screws from those three holes, plus from the two other holes at the bottom of the case. Note that one screw is longer than the others.
- Pop open the plastic back cover of the H4n, this is the part that comes off first. Do NOT try to remove the front cover, and don't even allow it to flex as it is still attached by screws that can only be accessed from inside the unit. To remove the back cover, insert a small slotted screwdriver blade in the seam between the side panel insert and the back cover where shown (see photo below) and twist the screwdriver to pop open the detent. Do this on each side.
- Carefully lift off the back cover but note that it will remain attached by some wires (see photo below). Write down the details of how the wires are routed and how and where the connectors are attached. Then use needle-nose pliers to unplug the connectors. Don't pull on the wires, pull on the connector body. If necessary, use a small slotted screwdriver to pry the connectors loose.
- Note the small plastic slider on top of the Stamina switch. Observe how it sits on top of the switch with the switch tang in the hole on the bottom of the slider, then remove the plastic slider so it doesn't fall off and get lost.
- Remove the four small black screws from the back of the built-in mic assembly, note which holes they came from because there are three different sizes.
- Observe the small flat cable attached to the mic assembly circuit board. You must remove this flat cable from the connector on the mic assembly circuit board before you can remove the main circuit boards. Note that there are two small brown retainer tabs, one on each side of the connector body. Using a small slotted screwdriver blade, pry the brown retainer tabs out from the connector body (see photo below). The brown tabs don't come off the connector body, just move them away about 1 mm, a little at a time, equally for each side. In the picture below, they are about halfway done. Then gently grab the flat cable with needle-nose pliers and unplug it from the connector. Done properly, the flat cable unplugs without any force at all, so if it resists, the retainer tabs are not out far enough.
- Remove the two shiny screws that hold the mic assembly to the circuit boards, then detach the mic assembly and set it aside.
- Like you did before, pop off the front cover of the H4n by inserting a small slotted screwdriver blade in the seam between the side panel insert and the front cover and twisting the screwdriver to pop open the detent. Do this on each side.
- Holding the unit by the side panel inserts, lift the "guts" out of the front cover and put them down gently (see photo below). Note that the LCD screen will be hanging by its wires, so do this step gently. Avoid scratching the front of the LCD, plus don't get dust or fingerprints on the LCD or the inside of the front window.
- On my unit, the Record button wasn't attached to the front cover, so it can fall out of its hole in the front cover. The other buttons seemed to be attached to the cover.
- Before you take the side panel inserts off, closely observe how they hold the stack of circuit boards together, plus how they align with the pushbutton switches on the edges of the circuit boards. Note that the On/Off switch has a separate plastic slider, similar to the Stamina switch, except that it is attached to the side panel and won't fall off. This slider has a notch that mates with a tang on the actual switch.
- The stack of three main circuit boards is held together by two small mating connectors, one between the center board and the top small board, and one between the center board and the bottom LCD board. You can separate the boards by gently pulling them apart. Don't twist them or wiggle them, just pull them apart vertically. There seems to be another mating connector between the main board and the combo jack board, but I did not separate those boards because it seemed like there might be other things holding them together.
- You can take the metal cover off the SD card assembly to better see what's underneath, but BEWARE, some parts will fall out including a tiny piece of stiff wire. This is the piece that makes the card latch and unlatch as you push it into the holder. It took me a while to figure out where the wire went, and without it, the card will not stay latched in the holder.
- Reassembly is the reverse of disassembly. Be sure to properly locate the side panel inserts on each side of the circuit board stack before placing the guts in the front cover (you can't fit the panels in afterwards). As you put the one side panel on, be sure you properly mate the notch on the plastic slider with the tang on the On/Off switch. Make sure the Record button is fully inserted into its front cover hole. Be sure the LCD and window are clean, and as you place the guts into the front cover, be sure the LCD sits squarely in the window area of the front cover. Remember to snap the detents closed to hold the side panels in place. Remember to properly mate the plastic slider on the Stamina switch. When inserting and tightening screws, try to carefully re-engage the existing threads so you don't cross-thread the screws. You can do this by putting a screw into its hole, then slowly turning it backwards (as if to loosen it) until you feel the threads drop into place, then turning it the correct way. Don't over-tighten the screws, secure them well but remember these are tiny parts and a little torque goes a long way.
- After reassembly, you will probably have to reset the date and time, since the batteries were removed for a while. Then, make a test recording in stereo mode and play it back to make sure everything still works.
- John Santic
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