TrevaP

🙂 That did occur to me.

Just to let you know - replacing Q3 did the trick 👍

How many people have forked out $250 for a new MB without knowing that a $2 transistor will get it going?

OK - nothing else is jumping out at me and troubleshooting boards like this isn't my strong point so we'll just replace the transistor and see what happens.

There's one thing - while removing the RA connector from the board when I did the Rowan mod, I may have damaged one or more of the soldered connections.  I managed to pull the entire connector from the board this time (replacing the bearings with SKF) and resoldered it. Whether or not those connections were dodgy after my first intrusion I have no idea - likewise the possible consequenses.

The mount was working just fine up til the Meridian Shift, load was nothing heavy (WO GT81) and there were no cable snags.

I get that Malcolm and I'm taking a punt that the mount may be on the edge of overvoltage at ~13.5V.

If it's something else so be it; it's a cheap fix to try before buying another MB - anyway I'll let y'all know how it goes.

I bought the mount second hand so warranty isn't an option but I found these which should (?) do the job. (I lashed out and bought 2!) If it blows I'll replace it, think about what may be a more robust replacement and perhaps drop the supply voltage a little.

What is it with Q3 on these boards. The mount (HEQ5 Pro) died in the middle of a meridian flip. I removed the MB and after reading this thread checked out Q3 - sure enough, it was fried.

I'm running this from a LiFePO4 battery at ~13.4V. Never had a problem with this mount or my Az-EQ5. I've been led to believe that this is a safe and even preferable voltage to use. True?