SMXII Keypad issues

[Strecker25]

Our cruisair unit is controlled by an SMX ii AB control pad. It started flaking out early in the season and the display would go wacky and the lights on all the buttons flashed, yet the AC/heat would still run properly and to whatever temp it was set.

More recently, if left on for more than 10-15 minutes the display turns off completely and the AC unit just runs continuously. I found a company called flightsystems that can test both the control board and control panel and repair if necessary.

Anything I can try first? I took the SMX panel out but aside from the connector there's not much to look at.

 

[CliffA]

Our cruisair unit is controlled by an SMX ii AB control pad. It started flaking out early in the season and the display would go wacky and the lights on all the buttons flashed, yet the AC/heat would still run properly and to whatever temp it was set.

More recently, if left on for more than 10-15 minutes the display turns off completely and the AC unit just runs continuously. I found a company called flightsystems that can test both the control board and control panel and repair if necessary.

Anything I can try first? I took the SMX panel out but aside from the connector there's not much to look at.

seems like I remember reading a fairly recent post about resetting the key pad when these type issues start....don't remember which forum it was in....maybe a google search can turn up the reset procedure....

cliff

 

[ttmott]

SYMPTOM: Erratic or Erroneous SMX Temperature Display.
• Perform a Factory Memory Reset (Press OFF/SET/FAN together, then SET).
• Check temperature sensor, cable and connection.
• Make sure the temperature sensor is installed properly in air return.
• Calibrate temperature: Press OFF then SET. Press SET and UP together. Sensed temperature is displayed. Use UP or DOWN to adjust sensed temperature to match actual temperature as measured at air return. Press OFF to exit calibration mode.
• Repair or replace power/logic board (see NOTE 2 below).

SYMPTOM: Erratic SMX operation.
• Perform a Factory Memory Reset (Press OFF/SET/FAN together, then SET).
• Check CX/CXP cable (power/logic to keypad) and connections.
• Check temperature sensor, cable and connection.
• Check change-over thermostat in air handler (if equipped).
• Repair or replace SMX keypad assembly (see NOTE 1 below).
• Repair or replace SMX power/logic board (see NOTE 2 below). SYMPTOM: Water dripping inside cabin or compartment.
• Check/clean out condensate drain pan and fittings.
• Clear blockage in drain hose.
• Make sure hose is routed downhill for drainage.
• Make sure insulation around ducting is not missing or compressed.
• Check for leaks in water loop and/or piping.

NOTE 1: The SMX II keypad can fail in several different ways, each presenting certain symptoms. One or more functions may become erratic or inoperative. This is usually due to cracks developing in the flexible circuit traces which are an integral part of the membrane switch portion of the keypad assembly. Occasionally, the UP temperature button will make contact by itself, thereby running the set temperature up to the maximum, with the result of shutting down the A/C and possibly turning on the heat. This problem is caused by tiny “whiskers” that grow between the contacts of the UP membrane switch. For diagnostic purposes, the keypad assembly can be easily swapped out with a known good one from another part of the boat (or borrowed). To remove the keypad, lift up on the bottom edge of the plastic bezel. Remove the four mounting screws. Carefully remove the keypad from the bulkhead and unplug the four-pin connector. Flight Systems offers a repair/rebuild program that features a completely new upgraded keypad with extended life and an improved tactile feel.

NOTE 2: The power/logic board and other associated components are housed in a metal box located on the central unit (compressor). Before removing the box for service, make sure the power is off and take a digital photo of the wiring connections. Unplug the temperature sensor and keypad cables. Carefully disconnect the other wires and then remove the mounting screws and wire ties. Flight Systems offers a repair/rebuild program for this unit.

 

[JimT]

seems like I remember reading a fairly recent post about resetting the key pad when these type issues start....don't remember which forum it was in....maybe a google search can turn up the reset procedure....

cliff

the reset procedure is in the operators manual. You can find it online if you don't have one.

 

[Alegria]

The keypad and temp sensor are grey wires that plug into the box. Make sure they are seated properly. Mine were pulled loose when I stored items in the storage space the logic box is mounted in. Pushed them in and the issue went away.

 

[Skuza]

Mines flashes or goes dim. My fix has been unscrewing the pad, unplugging the board and then plugging it back in. I don't know if that resets something or "cleans" the contacts on that plug. This procedure has worked every time.

 

[srkartholl]

Had a similar problem with the SMX II on my 460, the 'set temp' would run to 99. 'Flightsystems' told me that's a common problem, the gel in the pushbutton pads over time cause all sorts of weird problems. They rebuilt my control panel, really good price with very quick service. Good folks, good experience.

 

[bbwhitejr]

Performing the factory reset as per the instructions made mine perform much better.

Bennett

 

[Chambless Sanity]

Had a similar problem with the SMX II on my 460, the 'set temp' would run to 99. 'Flightsystems' told me that's a common problem, the gel in the pushbutton pads over time cause all sorts of weird problems. They rebuilt my control panel, really good price with very quick service. Good folks, good experience.

How much did they charge? What was the process? I'm having the same issue, just started last weekend...I'm going to try to reset first...

 

[JVM225]

Had a similar problem with the SMX II on my 460, the 'set temp' would run to 99. 'Flightsystems' told me that's a common problem, the gel in the pushbutton pads over time cause all sorts of weird problems. They rebuilt my control panel, really good price with very quick service. Good folks, good experience.

I had problems with one of mine and they told me it wasn’t rebuildable so I had to get a new one from them.
These things appear to be very delicate so I ordered a remote from them so I don’t have to keep pressing in the keypad all the time.
The remote is way more convenient and controls both of of my key pads. Just point it at the one you want to adjust.

 

[Henry Boyd]

Filightsystems.com will either rebuild yours, or sell you one of their brand new redesigned versions. The issue is as I understand from having had issues with the one on the 280 is that the keypad board cracks from use and causes the circuits to get scrambled.