DEC equipment - UK only.

[daver2]

The dodgy MMJ connectors again...

I won't comment about the password. Hopefully, it wasn't written on a yellow post-it note as well...

If you search for an MYG-14K241 you should be able to find that data sheet for that. It looks like a 14mm diameter 150VAC / 200VDC MOV - which is not compatible with the stated 240V (although the data sheet does mention 240V - the 241 section of the part number)...

Mouser do some equivalents that should be fine.

Dave

 

[bqt]

The dodgy MMJ connectors again...

Interesting. I've never had any problems with MMJ connectors. Is it DEC manufactured ones, or self crimped? Have you tried just cleaning the connector surfaces of the plug (in case there is oxidation on them)?
Anything else interesting observed around this? When it works when fiddling with the cable, either a bad crimping, or oxidized surfaces immediately springs to my mind at least.

 

[daver2]

Dodgy in the sense that they are so small and fragile that they get 'used and abused' by users and then they become a problem...

Dave

 

[Gary C]

I think its dodgy because it looks as if its been run over ! looks like poor crimping as the top of the blades look a bit of a mess and the clear plastic dividers are a bit displaced.

Got some on order.

First machine fired up for the first time. Its been sat for a while due to the PSU problem, but the second machine allowed me to do some diagnosis and to actually tell what the failed component actually was (the original has somewhat disintegrated) and now I know it was a varistor and that it saved the PSU.

Varistor taken out of circuit for now as its failure was due to powering up at 240 when its a 110V machine (glad the protection was there). In my defense, it wasn't obvious



There is a cable missing from one drive to the front panel so it wont spin up, but one drive does so the machine is looking good.

Need to do some work on the drive mounts as the rubber mounting have perished so they flop about a bit.



Dave, At least it wasn't on a yellow sticky but on my 4000 it was written inside the little drop down flap.

Found a link to a supplier (https://www.searchelec.com/product-details/?Itemnumber=ZNR14K241U) that also states an equivalent as ERZC14DK241U (which is also no longer manufactured) but for that I can find a datasheet and from that, I think ERZV14D241 from RS appears to have the same spec with the 'varistor voltage' of 240 volts.

I like to order from RS as I get free delivery.

 

[daver2]

>>> Dave, At least it wasn't on a yellow sticky but on my 4000 it was written inside the little drop down flap.

You have to either laugh or cry don't you !

On the haul I brought back - I went through the process of trying to determine what was truly multi-voltage or single voltage but set incorrectly. I identified that most things could be powered from 110 or 230 Volts. A couple of items clearly had switches. After that - it was in the lap of the gods and I just powered it up expecting it to either work or go bang...

I remember when we had our two micros and supermini shipped to Gloucester for development all those years ago. I think our student had powered up 3 Sigma graphics units before I managed to stop him destroying any more. Strangely, the first one he tried didn't work. Neither did the second.. The third one didn't either... Yes, they were all delivered configured as 110V for site - and he had never come across 110V before - so just plugged them into the 240V wall sockets. Oh well, we wouldn't do anything like that now would we ?

Dave

 

[Gary C]

I remember an engineer who had also just started who wired up a 110V signal to a 48V Robinson alarm DRAM input, it didn't like it. Also someone who spec'ed 110V AC solenoid coils on a 110V DC system and couldn't work out why they kept failing.
The value of experience.

The 3300 has two different PSU's supplied by DEC, one for 110V, one for 240V and they cannot be modified to work on the different supply (apparently), so unless I buy a new PSU (expensive) I am stuck with my Sturdy transformer, but after a bit of a buff up and reconnecting the earth in one socket, its working fine.

I have discovered the disk drives are mounted on Military spec Barry (!) ME-500 high deflection mounts, just need to find a source in the UK.