steve dove
New Member
Hello all
I have a Hitachi V1100A oscilloscope,that has had a fault that had been kicking in,after approx 10-15 mins operation,it loses 100 volt dc supply rail.,drops down to its ajacent which is 35-40
i am an electronics engineer by trade,i have to say though this one has run me somewhat
ragged,i disconnected the external points where this voltage goes,still same result.
the issue when it first showed up,took longer to occur,but got to happen over a shorter
period,then would not show crt trace at all,same with cursor,i have considered the possibility of thermal protection in the power transformer,this scope comes with user manual that has all the cct layout,schematics inside,i can find nothing re owner faults with these anywhere,my feeling is the problem is either in the rail mentioned,or poss thermal cut,the schem showing power transformer shows the windings,but no indication of thermal protection,so quite possible does not have it,if anyone has sufffered likewise problem with this type or one in this model range,please get in touch i would like to repair it,is in very good condition,have had it since new in box,still have all the original Hitachi packaging,has not had a great deal of use,so if repair can be done,likely go on years it has a lot of features,on screen cursor measurement etc,i dont want to bin it,but if nothing comes of this posting,i may offer it to someone who can bring it back to good order,crt is perfect fix the fault and thats it,only other point was one of the panel pots needed its fixing nut tightening.
rgds steve
I have a Hitachi V1100A oscilloscope,that has had a fault that had been kicking in,after approx 10-15 mins operation,it loses 100 volt dc supply rail.,drops down to its ajacent which is 35-40
i am an electronics engineer by trade,i have to say though this one has run me somewhat
ragged,i disconnected the external points where this voltage goes,still same result.
the issue when it first showed up,took longer to occur,but got to happen over a shorter
period,then would not show crt trace at all,same with cursor,i have considered the possibility of thermal protection in the power transformer,this scope comes with user manual that has all the cct layout,schematics inside,i can find nothing re owner faults with these anywhere,my feeling is the problem is either in the rail mentioned,or poss thermal cut,the schem showing power transformer shows the windings,but no indication of thermal protection,so quite possible does not have it,if anyone has sufffered likewise problem with this type or one in this model range,please get in touch i would like to repair it,is in very good condition,have had it since new in box,still have all the original Hitachi packaging,has not had a great deal of use,so if repair can be done,likely go on years it has a lot of features,on screen cursor measurement etc,i dont want to bin it,but if nothing comes of this posting,i may offer it to someone who can bring it back to good order,crt is perfect fix the fault and thats it,only other point was one of the panel pots needed its fixing nut tightening.
rgds steve
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