Blown 7i84

With Q1 open, what do you have between L1,L2,and L3?

It is a CEE 16A five pin. No changes on the wall, socket or cable. The MAHO has been working without wiring change from this socket for about 6 years.

Yes, neutral is wired in, but unused by the machine. Since the original Phillips PC used 110VAC generated by the 6T1, I wired the LinuxCNC PC and monitor into the same service.

Okay, this got weirder. I just went down to the machine,  manually switched off 1Q1 (I misunderstood that as Q1), plugged in and switched the machine on (with Q1, the main power switch), and PC powered up normally. Switched Q1off, reset 1Q1 to on, switched the machine on again, and it again powered up the PC normally. measured 114VAC between pins 150/151.  I could see from the Mesa LED's that the 24VDC rail 204 was also powered. I changed nothing other than waiting a couple of hours and plugging / unplugging the socket a couple of times.

Writing this, I just realised I need to open up that CEE plug on the machine cable, and see if I have a loose connection in there.

I am a slow learner... yes, the plug was the problem....

 

One phase disconnected, but loosely held in contact by the wire. I cut off the old ferrule, reterminated it with a new ferrule and now the machine is getting all phases.

It is still not clear to me whether this 7i84 can be saved with replacement NCV7608s or whether it is trash.

 

I will order a 7i84u for the Maho, but if this 7i84 can be rescued, I would use it in the Schaublin, where I ran out of 24V outputs, and bodged switching chinese relay boards with 5V outputs.

If you don't get the red fault light at startup,
(after removing the driver chips and with field power applied)
That likely means the 3.3V regulator and or DSPIC chip are toast.

Thanks Peter, I didn't realise I was to connect field power for this test. I just did, and only get steady yellow lights on CR2 and CR8. No red fault light.

I just tried it again, but there in not even a flicker from the red fault LED.

For posterity, here is the video of my issue...

 

Simi02 wrote:

@RotarySMP could I maybe ask you a few questions about your retrofit?

 

I would recommend you start a new thread for your 400E conversion. If you ask your questions in an unrelated thread like this, or my long 400E conversion thread, the answers become very hard for others to find.