Martin Mac 250 old ones Problems with FeER

[tinnitus_man]

I Have a Martin Mac 250 I have the error that appears on the Display FbER I have had this problem before and it turned out to be the thermal trip. On this particular Martin Mac 250 FpER only appears after the lamp has come on. I have spent most of the day trying to fix this unit. I have replaced lamp, Ballast, igniter, main mother board, both opto sensors on pan and tilt. I took al the bits off another martin mac 250 that works of course this will have to be put back together again! I'm rather lost now and I'm left scratching my head thinking what can it be?? I should say that it goes through the start up test fine and it starts to go through the test OK and then the Pan Tilt just doesn't happen. I also am now getting LERR coming up which is why I thought I would swap out the Ballast Lamp and Igniter and of course if you get any arching in these it causes fault errors due to mains type spikes going through the whole unit. Has anyone got any ideas?? Why should I get FbER and not FbEP (Feedback error Pan) OR FbET (Feedback error Tilt) as you would think if one of the opto had gone down? Do the sensors share a common supply rail? A diagram would be good to see if they do? does anyone have one?

 

Please help anyone

[stuart.thompson]

Hi,

 

Looks like you have a problem with your light sensor circuit, either the light sensor itself is faulty or the wires between the light sensor and the main PCB are broken.

 

Do a quick continuity test on the wires to eliminate them then change the light sensor if its not the wires. You will find the FbER( Feedback error in pan and tilt) will be related to this problem. When a MAC detects a lamp not oppereating correctly it will shut down all pan and tilt functions as a saftey precaution to stop it showering hot glass on the audience below. This will probably be the reasoning for the FbER appearing after you strike the lamp.

 

LERR ( Lamp error ) will appear when the PCB has sent a lamp on command has detected light through the light sensor but the light then suddenly disapears. I.E either a blown lamp or a mafuntioning light sensor/wireset.

 

and for future reference HOT will appear when the PCB has sent a lamp on command but the light sensor never detects a light source at all.