Jim Meade Posted August 20, 2013 Report Share Posted August 20, 2013 The flap system on my '07 SW works as designed. However, the little LCD (or whatever it is) display does not always indicate the correct setting, especially on start up. Sometimes it will start up blank (no reading, no lights). Sometimes it will start up with an accurate reading but when moving the flaps for a pre-flight check the display will remain on the start-up setting and not show the flap movement. A couple of times it shows a blinking light, such as we see when a flap is in motion, even though the flap is on the correct position (have cycled the flap and made sure it is correct but the blinking light continues). Usually (not always) the flap indicator display can be reset by pulling the battery breaker and reengaging it. From there on it is almost always (not 100%) right for the rest of the flight. Once the plane is flying and the display reads correctly, I've never had it fail. It would seem to me that something in the starting sequence can go bad intermittently. The device intrinsically has the capability of working right. This has been going on for nearly a year. Again - the electric flap control switch functions perfectly. You can tell your flap setting by looking at the knob pointer (and looking at the flap). It is only the display that is bad. 1. Has anyone had or know of a problem like this? 2. Does anyone have a good, used board that I could swap out? Thanks for any help. Link to comment Share on other sites More sharing options...
Jim Meade Posted August 20, 2013 Author Report Share Posted August 20, 2013 My first test (just thought of it) is to disengage the flap circuit breaker and start the engine, then engage the flap circuit breaker and see if that has any different result. My question is whether there is some electrical phenomenon (power surge, etc.) associated with an engine start that is wreaking havoc with my flap display. I'll test that later today. Other ideas or comments still welcome. Link to comment Share on other sites More sharing options...
Roger Lee Posted August 20, 2013 Report Share Posted August 20, 2013 Here is the most likely causing. First pull the lower center panel and push and twist all bullet connectors that go to the flap circuit board. Don't just touch each bullet connector. Make sure you push and twist each one. Several people have missed the problem just by looking for a dangling wire.This is a common cause and yours certainly acts like a loose connection. This doesn't sound like a bad circuit board so far, but there is a very small chance. Link to comment Share on other sites More sharing options...
Jim Meade Posted August 20, 2013 Author Report Share Posted August 20, 2013 OK, Roger, I'll try your suggestion first and hope it works. If it doesn't, I'll try mine and report back. Link to comment Share on other sites More sharing options...
Roger Lee Posted August 20, 2013 Report Share Posted August 20, 2013 It can't be the potentiometer, but if it isn't the bullet connectors then it could be the mother board. Squeeze and manipulate the mother board if the bullet connectors don't work. I know this doesn't sound very scientific, but I have found 1-2 bad boards by doing this. The board develops a bad connection across one of its circuits so it is an intermittent problem. Yours still sounds like a loose connection. Link to comment Share on other sites More sharing options...
CT4ME Posted August 20, 2013 Report Share Posted August 20, 2013 There have been problems with the circuit board going bad. Mine started out like yours and got worse. It would work for weeks then not. Isolated it to a crack or bad solder joint, as we could get it to work by flexing/pressing the board. Finally, the pre-sets stopped altogether, and I just use the manual up.down now. Tim Link to comment Share on other sites More sharing options...
Jim Meade Posted August 21, 2013 Author Report Share Posted August 21, 2013 I took it out and inspected it. Looked OK. Disconnected and cleaned the one multi-connector. Put it back together. It didn't work at all - flaps did not respond but the display did show the setting the pointer was aimed at. Fiddled a bit with some fastener torques just to be sure it wasn't twisting the board. Did a dozen or more resets. Then, it started to work again and worked flawlessly. From what you guys are reporting, I am not developing a lot of confidence. The board is over $1200 new. I can see why one might operate on manual. It worked in all regards today, but I must confess I am going to keep a close eye on it and operate with a potential failure in mind. Thanks for the suggestions. BTW, the big flap breaker does not seem to disengage readily, so I couldn't try my idea of it receiving a power surge on start up. Link to comment Share on other sites More sharing options...
Roger Lee Posted August 21, 2013 Report Share Posted August 21, 2013 Out of curiosity did you push and twist all the bullet connectors? There are about a dozen of them. If you did and it didn't work, but then manually squeezing or tweaking the board made it work then you may have the same issue as Tim. A small hidden crack in the board and when squeezed makes it re-connect until you let go or the next time vibration works on it. I remember when I thought $800 was a lot for that board, now it's $1200. ouch. Link to comment Share on other sites More sharing options...
Jim Meade Posted August 21, 2013 Author Report Share Posted August 21, 2013 There were no bullet connectors on my board or on any wires leading to it, that I saw. Just the multi-plug connector about .75 or 1 inch square. If the bullet connectors are way downstream from the the panel then I didn't see them. I've heard there are as many as three different boards and replacement boards may need to be rewired.. My plane is an early '07. The only chip that is in a socket is parked PIC16F873A-1/SP M045042P. Everything else is surface mounted. I didn't see any obvious cracks, listers, discoloration, swelling or other obvious indication of a fault. Link to comment Share on other sites More sharing options...
Roger Lee Posted August 21, 2013 Report Share Posted August 21, 2013 Interesting. Your problem then may lie in the multi-plug or still maybe the board. Tim's board shows no signs of any issue and only if you squeeze it can you make it work. We have looked with a magnifying glass. Link to comment Share on other sites More sharing options...
Doug G. Posted August 21, 2013 Report Share Posted August 21, 2013 Cracks in circuit boards are extremely difficult to see. the board itself will not be cracked, just a solder trace our a component pin connection may have a nearly microscopic crack. I have dealt with this in ham radio and computers - it can be a real PITA. Link to comment Share on other sites More sharing options...
Jim Meade Posted August 25, 2013 Author Report Share Posted August 25, 2013 Battery tender overnight. Cleaned all battery, starter, ground, regulator and other contacts. Started airplanen normally with flaps at 0. This time, the flaps LCD dimmed slightly but did not go out. This is an improvement. It implies that I had a high resistance contact that was causing a voltage drop or negative transient that was below spec and that this was fixed or improved. So far so good. Getting ready for takeoff I set flaps 15. Flap motor sounded and flaps moved but LCD stayed at 0. Checked several flap settings. Stayed at 0 display. Drat. Disengaged bat breaker and reengaged it. It showed the right setting. Cycled the flaps and the LCD display followed the flap accurately then and for the rest of the flight. Apparently, the board will work right but there is still a voltage issue on start up. I could put in a new battery - that would not hurt. I could also put in a starter battery and take the flaps off that battery. I could probably switch the flaps so they could be set off at start up. I'll think about all of these options and any that you would suggest. Obviously, there is no reason to buy a new board yet. Link to comment Share on other sites More sharing options...
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