Aww crap, I blew something (PDP-11)

[Tony Duell]

> 
> Well, I was hooking up my KY11-LB front panel to the machine I have moved=
>  into a BA11-K, and after testing it several times, I saw a (not very big=
> ) flash from near the PSU and the machine quit working.  I inspected the =
> power supply modules (two H7441 regulators and one H745) and it wasn=E2=80=
> =99t fuses, so I am baffled as to what happened. =20

'Near the PSU' or inside the PSU? Could it be something on one of the 
PCBs? 

When you turn it on now, does _anything_ happen? Do the fans start? Does 
the relay in the power control module -- under the mains transformer -- 
pull in? 

I would start by going back to basics. Unplug the backplane power 
connectors from the distrubtion PCB under the machine. Unplug the 
connectors from the regulator bricks. What you want to do is at least get 
the transformer to power up again.


> 
> =20
> 
> I was SOOOO close too, I had got the front panel lights working, the RUN =
> light flashed on power up like it should have, then I realized the power =
> switch was on backwards, cause when you set it from DC OFF to POWER ON (o=
> r whatever, this is off the top of my head) it would turn off.  I switche=
> d the leads, then that=E2=80=99s when it popped.

What exactly did you swap round, and where? 

> 
> =20
> 
> I had the leads connected to J3 on the power distribution portion of the =
> power supply (the module that has the power cord attached to it)

That sounds right. On the front of that module (I call it the power 
controller, I have no idea what the official name is), there's a 4 pin 
connector that's the mains to the transformer primary windings. And 3 pin 
connecotrs (on both the front and the back) that are the normal DEC power 
control bus I mentioned here the other day.

-tony