VERAULT
Veteran Member
I was finishing up a CRT repair and pulled out what has become my primary meter in the past years. An Extech EX530. I got it sometime around 2012 or 2013 I think as a backup meter at work. I found it to be a really good meter for the price.
Anyway I ws turning the rotary knob when it just came apart inside and was free spinning. I was livid. I wouldnt expect something 10 years old to fail so badly for what we paid for it.
I took the unit completely apart for the first time ever and this is what I found.
The drive has a hexagon bit made of plastic which fits into a hexagon shaped hole on another rotary disc with metal fingers to make contact on which ever setting you have it set to.
IT rides clipped into a groove using two springs and two small ball bearings to make the tactile click. Unfortunately the entire mech is plastic.
I found the hexagon receptacle completely shattered. All 6 sides broke off into individual pieces. I spent an hour at least with tweezers and superglue just to get them back into the shape of the hexagon. Its no longer of equal size but it was the best I could do. I knew superglue had no chance of working. So once the super dried I added a small amount of epoxy resin to sort of force the hexagon shape to stay where it is.
Unfortunatley there is no Keyway to determine where the knob should rest. I figured the diagnal line of empty space in the metal contacts must be the OFF position so I fought with assembling the knob mechanism. There is slight play now but its not terrible. The hardest part was snapping the back disk onto the front knob pushing the tiny ball bearings into a recess while the two clips lock onto the circle channel. I was able to get it working and inserted and the CLICK while turning is working.
I mostly assembled the meter just to see if the knob worked and if the screen still worked. I made the mistake of removing all the screws to the screen even though I didnt need to since the screws for removing the pcb and the lcd were all circled in white silkscreen. The screen had a zebra connector so I was pretty nervous getting it aligned would be trouble. But thankfully it wasnt.
The meter came back to life but the knob was on 180 degrees the opposite of what it was supposed to be. So I took the pcb out again and thankfully didnt have to dismantle the knob mechanism just free spin it 180 degrees then reinsert.
And that was it. IT went back together and tested good.
The fact that this green plastic is already brittle means this will be a temporary fix. I dont know how long I will get but hopefully another year or two.
Strangely enough I had to plastic weld the battery door about 5 years ago so I guess I just didnt see the signs of how terrible this plastic is.
I always thought this thing has a pretty unique Serial number.
And to sum things up I think this logo was put on wrong from the factory. The trash bin should have been on the right side WITHOUT an X running through it.
Anyway I ws turning the rotary knob when it just came apart inside and was free spinning. I was livid. I wouldnt expect something 10 years old to fail so badly for what we paid for it.
I took the unit completely apart for the first time ever and this is what I found.
The drive has a hexagon bit made of plastic which fits into a hexagon shaped hole on another rotary disc with metal fingers to make contact on which ever setting you have it set to.
IT rides clipped into a groove using two springs and two small ball bearings to make the tactile click. Unfortunately the entire mech is plastic.
I found the hexagon receptacle completely shattered. All 6 sides broke off into individual pieces. I spent an hour at least with tweezers and superglue just to get them back into the shape of the hexagon. Its no longer of equal size but it was the best I could do. I knew superglue had no chance of working. So once the super dried I added a small amount of epoxy resin to sort of force the hexagon shape to stay where it is.
Unfortunatley there is no Keyway to determine where the knob should rest. I figured the diagnal line of empty space in the metal contacts must be the OFF position so I fought with assembling the knob mechanism. There is slight play now but its not terrible. The hardest part was snapping the back disk onto the front knob pushing the tiny ball bearings into a recess while the two clips lock onto the circle channel. I was able to get it working and inserted and the CLICK while turning is working.
I mostly assembled the meter just to see if the knob worked and if the screen still worked. I made the mistake of removing all the screws to the screen even though I didnt need to since the screws for removing the pcb and the lcd were all circled in white silkscreen. The screen had a zebra connector so I was pretty nervous getting it aligned would be trouble. But thankfully it wasnt.
The meter came back to life but the knob was on 180 degrees the opposite of what it was supposed to be. So I took the pcb out again and thankfully didnt have to dismantle the knob mechanism just free spin it 180 degrees then reinsert.
And that was it. IT went back together and tested good.
The fact that this green plastic is already brittle means this will be a temporary fix. I dont know how long I will get but hopefully another year or two.
Strangely enough I had to plastic weld the battery door about 5 years ago so I guess I just didnt see the signs of how terrible this plastic is.
I always thought this thing has a pretty unique Serial number.
And to sum things up I think this logo was put on wrong from the factory. The trash bin should have been on the right side WITHOUT an X running through it.
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