exxos's Atari, Amiga & retro forum

And the boards have arrived at last.

I see some soldering in my near(ish) future and then probing of logics.

stephen_usher wrote: 01 Mar 2022 15:47 And the boards have arrived at last.

I see some soldering in my near(ish) future and then probing of logics.

Sounds splendid :)

I've made up the break-out board...


Much fun was had doing surface mount soldering. Grrr... :D

Anyway, it buzzed out, so it was on to trying to work out that the signals on the Sun 3/80 are.

Of cause, the first thing to try was powering up with just the chip relocated onto the board, and it had the same behaviour as when the chip was in the socket directly, which was a good start.

Next was to just throw the connections on in some order which may at least show some sort of data, though at this point probably nothing particularly useful.

So, wired it up...


Tired to work out how the heck to work the Tektronix and... Got something.


I've no idea what the signals mean yet as they all seem to be the same continuously, even though I know the machine's doing different stuff as at first it flashes the LED, as it should... it's about the first thing the ROM does after setting up the translation tables and just before accessing the serial ports for the first time.

I'm obviously going to have to do the instrumentation more rationally. I may also find it easier if I switch over to the computer based logic analyser as that seems more controllable and able to record a longer data length, triggered by a data line. I can't seem to work how to do this on the Tektronix.

By the way, if anyone wants one of these boards, I've four spare. You'd have to supply the socket and Winslow surface mount PLCC-44 plug.

Oh! It looks like I will have a C64 breadbin + tape drive and a whole load of stuff in the near future.

I bid on an auction last week and got outbid. However, the person won failed to pay so they've just phoned me up asking if I'd like to take up the offer to purchase.

Got a bit sidetracked from working on the Sun 3/80 this evening after dismantling the water damaged core network switch at work.

The main damage was to the power distribution board on the right-hand side of the unit. As you can see here, it was quite a mess and had a dead short between the PoE+ and PoE- sides of the board.


So, this evening I dismantled it and worked on getting it operational.

Well, the PoE side is shot. I had to drill out practically all the vias through the board before I could get rid of all the short circuits. Also one part of the PCB had been fully burnt through.


Anyway, it looks a lot better now. The +12V and ground connections are fine and the PoE is effectively isolated. Seeing as we don't use PoE on this unit that doesn't matter.


I just need to see if I can fix the interconnect between the two management units now by cleaning a couple of pins on the connector on the backplane. After that I can get the power supplies PAT tested and we'll have an emergency spare unit operational.

Unfortunately it still doesn't work. When the 48V for the PoE turns on the carbonised PCB starts conducting and there are sparks and flames.

It's going to have to be Dremel time, stripping back the copper.

Actually, I just cut the power planes back...


Other than complaining that the PoE power isn't working the Aruba core switch is now happy, so we can use the unit as an emergency replacement.

Holey moley! [make the sign of the cross on myself]

That's a nasty burnout.

We need a 'HW horror stories' section of the forums for stuff like this.

Must have been some amperage heating that up. :o

stephen_usher wrote: 03 Mar 2022 15:02 Actually, I just cut the power planes back...
IMG_2595.jpg
Other than complaining that the PoE power isn't working the Aruba core switch is now happy, so we can use the unit as an emergency replacement.

Wow, scorchio!!

I suppose no PoE is better than no switch, assuming you aren't using it for PoE devices.

mrbombermillzy wrote: 03 Mar 2022 15:13
We need a 'HW horror stories' section of the forums for stuff like this.

I like the sound of that :)