Dear Dave, If I understand elogs and your mail, as well as our discussion on the phone, the problem is in the upper stack of MV2. I seems to recall that it was also in MV2 that one flat-top had a problem. So we have to assume that MV2 cabinet is tricky. Thus, I would suggest you to spend some times to make systematics check. I would recommend you to start again with the measurement of all the drain-source resistor. See my report (attached again, in case you don't know where to find it) page 4, section measurement. Do it for the entire cabinet. If it is ok, then measure the little resistor as describe at the bottom of page 4. Figure 3 shows the little resistors (take a spare card to see it yourself first). It is a tricky measurement, because the grey resistor is hot! And then I would continue with the measurement on page 5. This will be done in DC mode, and you will be able to check each stack separately and correctly. Once you have all those measurements, we should have some "wrong" value somewhere and it would lead to the possible solution. If at any point, you see something wrong, try wiggling the optical fibre connected to the MOSFET card. It could mean that with the cleaning with air-pressure, we move them slightly away. Will call you again; best regards Frnacoise
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