Modifying the Lamp Module 

1. Change C1 (blue) from 0.68uF/250V to 0.33uF/400V.
2. Change R1 from 100Ohm/0.5W to 220Ohm/1W.
3. Change the 130V MOV to a 250V MOV.
4. If not already so, change R2 from 330K/0.25W to 330k/0.5W
5. If not already so, change R5 from 330k/0.25W to 330k/0.5w
6. If not already so, change R10 from 100k/0.25w to 100k/0.5w
7. if you have 240V, it would be safer to use a 600V triac. instead of BTA10-400CW which is a 400V version. But in a "clean" environment it would probably work.
8. Use adaptors for the connectors on the input and on the output.

Triac short form data:

Case TO220, insulated tab

Defeating local control of lights and appliances

Image of modification schematic

source: Tom Laureanno's X-10 Home Automation Webpage.

Local control is the feature that automatically turns the appliance module on when the device connected to it is turned on. Its based on current sensing circuitry that senses how much current is drawn by the load. The following modification disables the current sensing circuitry:

Procedure:

1. Disassemble module by unscrewing two screws at back side and carefully pushing the tabs on the bottom side. Separate the two halves of the case.
2. The area of interest is the diode marked D10, near the IC.
3. Snip the top of the diode.

Disasemble module

Locate zener diode D10

Snip top of lead of diode

Repairing a "blown" lamp module, part 1

source: newsgroup post by Dr. Ed Cheung

X10 lamp modules have a bad habit of dying premature deaths. Most of the time, the problem can be traced back to a bad triac. It is possible to "resurrect" the module by simply replacing the triac. Caution must be stressed here; there are a lot of triacs available, but whichever one you use must have an isolated tab. The most universally available replacement is from Radio Shack, part number 276-1000 [Does this part actually have an isolated tab?], or Digi-Key part number L4008L6-ND. In addition to having an isolated tab, it also has a higher rating than the original one, so will be less likely to fail.

See triac table above.

Repairing an overloaded lamp module, part 2

Source: Dominic Sgro, personal correspondence

Besides a dead triac, a lamp module can die because of a fried inductor. This happens due to overloading, with a the symptom possibly a dead lamp module stuck at ON. 

The inductor (choke) is the black cylindrical wire wrapping around a center core. The inductor is 110uH (microhenry), 6.8ohm, 20awg. Wire thickness with coating is 0.034". There are 72 turns around the choke.

It's possible to resurrect the coil:

Procedure:

1. Open up the module and de-solder the coil.
2. Unwind the coil, noticing direction of turn.
3. Rewind with a new wire, 20awg, 0.034#" thick (including coating), 72 turns + a few for adjustment.
4. If you have an analyzer, trim the coil to 110uH. Otherwise, just skip this and hope your count was OK.
5. Solder the coil and test. You don't have to assemble the module for this. Just send ON/OFF to Housecode M, Unitcode 13. Unassembled modules (with no dials on) respond to M13.
6. Reassemble.

Fixing lamp module that randomly turns on
Credit: Steve Bloom - newsgroup post

The WS467 wall switch (and I suspect it's variations, as well) does indeed "randomly" turn on. 

Specifically, under the correct conditions, a WS467 can "glitch" on due to a power spike from a large bank of magnetic ballast fluorescents on the same circuit, large motor, etc. And filter caps across the 78566 chip, resistor change in the "button" line nor MOVs do not help. 

The solution is actually quite simple, once it is figured out. The 78566 chip in the WS467 contains 2 unused pins (pin #8 and pin #9) who's function is unknown to me. However, manipulation of pin #9 can cause the WS467 to turn on the light. 

After discovering this, I have since tied pin #9 to -v and the "random" light turnons have stopped. My personal preference is to install a 10K 1/8-1/4w resistor across the top of the ic between pin #9 and pin #18. A hard wire will probably be ok, but not acceptable standard practice when dealing with bidirectional I/O pins.

Modification to a silent appliance module or universal module
Credit: Steve Bloom/ Ido Bar-Tana

The topics range from quieter appliance modules to ceiling fan control with wall switch to cheaper fluorscent
wall switches.
 
The answer is basically the same for all of these topics: convert a lamp module (LM465) or wall switch (WS467) into a true solid state switch.
 
My house has now been 100% click free for almost a year now, and this includes banks of fluorescents in the kitchen,
ceiling fans, attic boost fans, water heater, window air conditioners, bathroom fans, and stereo.
 
The solution is so simple:

1. Open up the lamp module or wall switch (wall switch must be a 3-wire model. mod if neccessary per schematic).

2. Remove the

• Triac (BTA10-400)

• choke (large coil wrapped in black tape)

• 1k resistor (connected to the triac, marked R5 on lamp module circuit board)

• Dual diodes (connected to the 1K resistor, marked D7 and D11 on lamp module circuit board)

• 39 ohm resistor (connected to the diodes, marked R10 on lamp module circuit board)

• I also remove all of the extra components associated with the remote sense-330k, diodes, BC557, 3.3uf cap. On the lamp module circuit board they are R, D8, D9, D10, C8 and TR1).
   
  
  
  
  
  

1. Drill and install a 16awg wire jumper instead of the removed coil

2. Add a crydom #CX240D5 (~$9.00) 5 amp solid state zero-crossing relay (SSR) with the SSR + terminal connected the modules "grd" (same reference point as the ic's pin#2) and the ssr - going to the collector of the transistor (C337) where the 39 ohm resistor went to.

3. Wire the SSR AC pins across the vacated triac position using heat shrink as appropriate.

4. Install a 22mfd electrolitic capacitor directly across the SSR + and - terminal observing polarity (the capacitor effectively removes dimming for a true on/off.  if dimming is commanded, ssr will simply turn on if brt enough, or off if dim enough).
    
   and, presto-chango, a truely useful "appliance" module or wall switch.
    
   Though not quite as neat and pretty, all of the crydom SSR ,regardless of amperage, has the same type of input interface. I used a wall switch, ran the SSR + and - terminals lines out of the case, and glued a crytom 50 amp SSR to the back, shoved it into a wall box, and it now controls my water heater. The same basic approach was used with the window air conditioners, but I hide the wall switch (with the entire metal plate and switch button removed) and the SSR behind the outlet in a deep box.

5. For local control, tie two wires to a switch, and the other ends of the wires tie as follows: one to minus terminal (terminal 4) of the Crydom SSR, and the other to the non-band side of D10. Now, when these two wires are shorted, via switch, the lamp modules conducts.

6. For dry contact (turning into something like the Universal module), connect the Crydom AC terminals to two wires, which will be shorted when the lamp module  is ON. 

Increasing Range and Reliability
Credits: )) Sonic ((
http://siber-sonic.com/X10/X10world.html

This modification requires testing and tweaking the module while it is connected to the mains powerline. This information is provided AS-IS, for informational purposes only, with no warranty whatsoever.   It is your responsibility to know and understand common safety procedures, especially those involving electricity at potentially dangerous power levels. Proceed at your own risk.

1. Start by reading the general alignment procedure

2. Disassemble the module . It is O.K. to either leave the front cover (with the House and Unit code dials) in place, or remove both covers and work with a bare PCB. Attach a very short extension cord, if needed, to allow for adjustment while module is powered.
3. Move the module to the location where it will be used. Bring along oscilloscope, isolation transformer (if needed), and previously calibrated controller of known correct frequency.
4. Connect the controller to a separate circuit, or at least an electrically distant outlet on the same circuit, via some means of attenuating its 120kHz output (as discussed in the general alignment principles)
5. Connect oscilloscope 10X probe to pin 1 of 78570 IC (i like to use the 33pF capacitor lead which attaches to pin 1), probe ground to circuit common (the narrower of the two A.C. prongs, i.e. “Hot”). Oscilloscope must be isolated from the A.C. powerline, since module must be directly connected for best results. Avoid touching oscilloscope while module is powered. I usually start with 10mV/div (X10=.1V/div actual), and 5µsec sweep.
6. Connect module directly to the A.C. line.
7. Key controller to generate a continuous signal (Bright or Dim achieve this on most controllers so equipped).
8. Inspect waveform. If there is clipping, reduce the amplitude of the signal from the controller until the displayed waveform is sinusoidal.
9. Adjust module transformer for maximum 120kHz signal amplitude. This is likely to be a broad, “low-Q” peak.
10. . Unplug/disconnect all.
11. . Reassemble module and test.

Power consumption measurements of dim and bright settings

Source: Doug Wilson, Personal Correspondence

I tried two different lamps on one sample of the plug-in lamp module.
Using a 50W "rough service" lamp, I measured the following (60Hz, approx 120VAC line voltage):

At fully on:
Conduction time 6.3ms (per half cycle)
RMS lamp voltage 117V
RMS lamp current 411mA
Calculated lamp power 48W

At fully dimmed:
Conduction time about 900us
RMS lamp voltage 11.4V
RMS lamp current 152mA (about 37% of full-on current)
Calculated lamp power 1.73W (about 3.6% of full-on power)

Dimmed "3 notches" using a keychain remote with the RF transceiver:
module (8 "notches" between full dim and fully on):
RMS lamp voltage 75V
RMS lamp current 360mA
Calculated lamp power 32.1W (about 66% of full-on power).

It was interesting to note how the PEAK current actually increased at
low conduction angles.

With this particular lamp, the peak current was about 300mA, and remained quite constant until the conduction angle was reduced to about
3.7ms. For conduction angles less than 3.7ms, the peak current became almost constant at about 400mA, right down to the minimum conduction
time (about 900us). On brightening from full dim, the current would briefly peak at about 500mA, then stabilize with the new filament
temperature.
All of this is consistent with the negative temperture coefficient of resistance of the lamp filament.

Since the voltage and current are almost exactly in phase (not quite, because of filament temperature coefficient - which is partially
cancelled by the reactance of the output filter inductor), it is legitimate to calculate power by taking the product of RMS current and
RMS voltage.

I did some similar tests with a 34W incandescent lamp, and the results were about the same - fully-dimmed power about 3% of the fully-on 
power.