MP chassis headache

[House]

First of all, to those that celebrate, hope you had a nice thanksgiving.

One of my spare mp chassis has a continuous back end end issue. After you turn it off, it should run for close to a minute and shut off. This one never shuts off unless you shut off the service disconnect, main circuit breaker, or main plug. no issues with power restored and when machine is in normal operation.

(using my other known good spare as a reference. the machine side c1 is fine, and two other chassis work fine with no issues. Problem is isolated to one specific chassis)

I have gone thru the entire c1, traced wires and inspected them. Had a bad wire, replaced it, problem still exists.

suspected a bad contact (welding/arcing) on the BE relay, swapped out relay with a known good one, problem still exists.

Even replaced the mp board for poops and giggles with the good one out of my spare, still no change

Again, everything works fine thru startup and in operation, just the back end is continuous.

Suggestions? Thanks.

[Kat]

Check the coil for the BE relay. Trace all the wires for the coil and make sure it's not running to ground.

[wb8yjf]

Did you try it on another lane?

[MarkyB]

know on a SS chassis its the M1/M2 relay, cant remember if Mp's have these, probably not, but if they do swap them out

[House]

Kat, when you say coil, do you mean the coil in the be relay?

Jon, the problem moves with the chassis.

[Kat]

Yup, the BE relay coil (24VAC).

[rivmike]

First of all, to those that celebrate, hope you had a nice thanksgiving.

One of my spare mp chassis has a continuous back end end issue. After you turn it off, it should run for close to a minute and shut off. This one never shuts off unless you shut off the service disconnect, main circuit breaker, or main plug. no issues with power restored and when machine is in normal operation.

(using my other known good spare as a reference. the machine side c1 is fine, and two other chassis work fine with no issues. Problem is isolated to one specific chassis)

I have gone thru the entire c1, traced wires and inspected them. Had a bad wire, replaced it, problem still exists.

suspected a bad contact (welding/arcing) on the BE relay, swapped out relay with a known good one, problem still exists.

Even replaced the mp board for poops and giggles with the good one out of my spare, still no change

Again, everything works fine thru startup and in operation, just the back end is continuous.

Suggestions? Thanks.

If you gently kick it will it shut off ? BEM relay

[felix]

"M" Glass Relay/Sockets

T4

[House]

Yup, the BE relay coil (24VAC).

not going to ground

[Tablejam]

The only time the be should not shut off in an MP is when either the sweep or table are not at electrical zero or a cycle has started as the machine is turned off.

[House]

The only time the be should not shut off in an MP is when either the sweep or table are not at electrical zero or a cycle has started as the machine is turned off.

Right, but I can get that to happen on any lane with this chassis installed. I even took measurements to make sure both assemblies stop at the same positions with a good chassis and the bad one. Both measurements are identical. It doesn't rule out it electrically, but does mechanically.

[AMF Brian]

When this is happening, is the up front ball return running when the lane is shut off as well, or just the back end motor? If M4 is staying engaged then I would lean to something causing both BEM relay and M4 from turning off.

[House]

i didnt even think to check the powerlift, will do that monday. thanks Brian.

[felix]

You can switch the "BE" wires from left to rigt and right to left. One side of the coil will carry the other.

[House]

You can switch the "BE" wires from left to rigt and right to left. One side of the coil will carry the other.

is that a suggestion for me to try you saying?