Megger BM222 Please help with Fault diagnostics

[Dazz]

Hi
I own a Megger BM222 meter with a fault. It works on the 500V range, but there is no output on the 1000V range.
I am trying to figure out what the fault is so I can fix it.

On the 500V range, I can hear the internal relay clicking when the button is pushed.
When I push the button on the 1000V range, no clicking can be heard.

If you have a BM222, can you please tell me if you can hear the relay click on the 1000V range?
Does anyone have a service manual???

 

[westward10]

Not used one of those for a while so I can't remember. First thing I would look at is the contacts on the switch selector.

 

[Dazz]

OK I will give that a try.
It's an oldy but a goody. It is old enough that I can probably still get components for it.

 

[Moley]

I had a similar problem with a BM 230, worked on everything except 1000v .There's an IC ( possibly a mosfet, can't remember) near the bottom right of the board (near a small transformer) that had gone t1ts up. I've got a non working 222 somewhere. It's about time I took a look at it.

 

[Dazz]

I can see there is a switch mode power supply in that area and around the relay. 1000Vdc is a lot for an electronic component to handle, so it makes sense a mosfet or similar is toast.

 

[Dazz]

I think my BM222 has been crippled. The attached image marks where I think a diode should be. The diode has been cut out. It is wired as an OR gate with the adjacent diode.

I think it should be a 1N914 small signal diode.

Can anyone confirm the missing component is a diode? Part number? @Moley ?
Thanks.