CM200DU-24F woes

[Usernametaken]

So I have been following the Loneoceans site and settled on a CM200DU-24F brick to power my coil.
I pulled the top off to cut the RTC and the goop inside wasn't transparent, it was opaque.
Today I figured I had nothing to lose so I carefully removed some of the goop so I could cut the wires and I've found that it's different inside to the CM200 picture I was using as a reference.
Any and all help appreciated.

[TDAF]

Looks pretty much the same to me

I guess the goop's very cloudy though so that might be obscuring the RTC

[Usernametaken]

No, they are different.
If you have a look, they are a different number of connections going to the dies and there isn't an RTC "pad".

[Hydron]

Is the brick you have the "24F" version? Or is it a "24H" or other variant?

Not all have the RTC circuit, you can normally tell by looking at the "gate leakage current" spec in the datasheet - the F has 40uA max (i.e. has a RTC), and the H has 0.5uA (no RTC).

[Usernametaken]

The sticker on the side says Mitsubishi CM200Du-24F.

[Hydron]

Hmm, interesting. It really does not look like there is an RTC circuit present - maybe the design has changed? Loneocean's units look like they have smaller IGBT dice (dies?), and are POWEREX branded rather than Mitsubishi (which I believe means they are newer).  Possibly the IGBT die size was reduced with newer technology, but to keep the same short circuit withstand capability they needed to add the RTC circuit?

You could check the Gate->Emitter resistance with a multimeter - check both directions (polarities) and see if it gives any reading, or just an open-circuit. If it's the latter then it adds to the evidence that there's probably no RTC.

[Usernametaken]

G1 and E1 are closed.
G2 and E2 are 6.8 Ohms each way.

[Hydron]

Do you have another brick you can test? I would expect to see open-circuit or high resistance rather than short-circuit (is that what you meant by "closed"?) or 6.8 ohms.

[Usernametaken]

Sorry.
G1 and E2 are open circuit both polarities.
G2 and E2 are 6.8 ohms both polarities.

[Mads Barnkob]

Is all the goop evenly hazy or was it like it has been cooked? Could indicate a abused/overheated brick.

Certainly does not seem to have a RTC, even the RTC in a CM600 is identical, as can be seen from where I remove it here

[Hydron]

Sorry.
G1 and E2 are open circuit both polarities.
G2 and E2 are 6.8 ohms both polarities.

In this case I suspect that there is no RTC, and that IGBT 2 (corresponds to E2 and G2) is damaged, either before you got it or during your removal of the goop. I would check the C2 resistance to E2 and G2 as well (IGBTs can short all 3 terminals when they fail), and also have a poke at the bond wires you've exposed incase you have accidentally moved them so that they touch and give you the 6.8 ohm short-circuit.

[Usernametaken]

I was extremely careful removing the goop so I suspect this is a dead brick.
A pity I didn't test it when I bought it a few years ago.
Sourcing a new brick now.

[Usernametaken]

Received my new CM200DU-24F and made sure it was a powerex brick, opened it up and it’s the exact same brick inside.
Gate to emitter resistance on both polarities are complete open circuit (meter doesn’t change, just measures a 1).

[Mads Barnkob]

Received my new CM200DU-24F and made sure it was a powerex brick, opened it up and it’s the exact same brick inside.
Gate to emitter resistance on both polarities are complete open circuit (meter doesn’t change, just measures a 1).

Do you have another meter to check with, be sure to rule out that the meter is broken/not fit for the measurement?

Try a static test with just +15V across G-E and check C-E conduction?

[Usernametaken]

I'll grab my other meter from work tomorrow but I think (hope!) this meter is ok.
And with 15V on G1 and E1 I have 13.8K over E2 - C1 (negative probe on E2) and open circuit the other way.
On G2 E2 I have 6.9K over E2 and C2E1 with the negative probe on C2 and 11.77k the other way.
These don't appear to change when I remove power.
There is also no chance in conductivity when I apply power to the gates.
This is using a 15V 500mA wall power adapter though.