Clear Board Sensor

[ruggybear]

I have been fighting the clear board sensor for some time now. I have worked with LHR techs (on death hold with them as I write this) and still no fix. What has been done follows:

1. Replaced the board sensor
2. Flossed the cable going from the board sensor behind the Z truck to the back of the Y truck.
3. Replaced the board tracking sensor tracking spring.

As of today I have further isolated the problem. If I do a sensor test for the board sensor I can make the reading go from 0 to 162 and back to 0 over and over. I place a sheet of white paper under the board sensor and lower the head almost down to the bottom. I have the Y truck somewhere in the mid position. I will get a reading around 150+. Moving the Y truck toward the keypad and watching the board sensor reading I see the reading flucuate a couple of times and then drop to around 22 as it moves the last 20% toward the keypad. Since 22 is not enough of a reading I will get the clear board sensor message when trying to get a project going. Moving the Y truck back to where I started returns the reading back to 150+.

The only thing that I can see that moves when locating the Y truck is the ribbon cable that plugs into the Y truck and I assume the Y encoder and motor.

I do not think the problem is the ribbon cable. I have checked it and it is seated fine.

Any ideas anyone? I am hanging up on LHR now and will call again later. Been on death hold for half an hour now.

Ken

[Bubbabear]

Ken I know some still do not believe it but since I added lights to the inside of my machine I don't seem to have that issue anymore. here is the link to the thread. http://forum.carvewright.com/showthr...ghlight=lights

[ruggybear]

bubbabear,

Thanks for the idea. However, I have plenty of light in my shop plus I had a drop light in the machine as I was testing.

Ken

[Digitalwoodshop]

While monitoring the numbers on the board detector move the flex cables and see if the numbers change.

Could be a broken LED, 1 of 2 and with shop lights on you get a good reading. When the head gets into the shade the numbers drop.

Could be a wire missing the insulation inside the Z. You said you flossed it, I had a wire that shorted to the metal and had to replace it.

When you order a sensor order the cable that goes through the Z if ONLY to use it to plug in a sensor above the machine to check a sensor for good or bad.

AL

[ruggybear]

While monitoring the numbers on the board detector move the flex cables and see if the numbers change.

Could be a broken LED, 1 of 2 and with shop lights on you get a good reading. When the head gets into the shade the numbers drop.

Could be a wire missing the insulation inside the Z. You said you flossed it, I had a wire that shorted to the metal and had to replace it.

When you order a sensor order the cable that goes through the Z if ONLY to use it to plug in a sensor above the machine to check a sensor for good or bad.

AL

Al,

Thanks for the post. I have played with the flex cable so that is not it and the board sensor is brand new so I doubt if it is an LED issue.

Ordering a sensor cable is a great idea. Could use to furhter troubleshoot the problrm. Really think it is something with moving the Y truck to toward the keypad. Have plenty of light. Will be calling LHR in the morning. Been down for two week now. Have projects lined up.

Ken

[ruggybear]

I will try to keep this as short as possible. Working with LHR tech HelpBot3000 we decieded to change out the FFC cable and head termination board. Well teyr arrived and the change was made with no improvement and actually a step backward. Now the 'Y' and "Z" trucks were not working either. When doing sensor check their reading read all 00000's.

Now comes the old divide and conquer routine for hardware troubleshooting. Began to swap out parts between the old and new FFC cables an the head terimal. The only combination that would show something was the original parts. However, not everything was correct. Sometimes the board sensor would not read correctly, sometimes the 'Z' motor would not work and sometimes it would. Finally noticed that the connector on the head terminal board for the FFC cable appeard to be loose. Removed head terminal board for further investigation.

Found the FFC connector to have a moving piece that was not staying in position to put pressure on the cable to pinch the cable to the contacts. I quickly mixed up some 5 minute epoxy and glued the moving piece in place permanetly. After drying I reinstalled all of the original parts (except board sensor-left new one in) and the machine now makes chips and dust.

Hardware Tech indicates that some of the newer parts do not work so will with the older parts sometimes. I will be sending the new defective parts back the the hardware supervisor for check out. My machine is one of the original 'A' machines.

This entire downtime (over 3 weeks) has been a comedy of errors. Without some knowledge of the machine and many years of hardware troubleshooting experience I expect the machine would be on its way South.

[MikeMcCoy]

Without some knowledge of the machine and many years of hardware troubleshooting experience I expect the machine would be on its way South.

If that had been one of my machines, it would already be in Texas. Sound like you got it beat though.

[DocWheeler]

Good work Ken!