Re: [midatlanticretro] PIC Morrow Wunderbuss Thinker Toys Motherboard Schematic/docs
- At 03:32 PM 5/8/2007 -0700, you wrote:
>Nice photo. Made me want to get some marshmallows...LOL
>Do you have fire insurance?
>--- B Degnan <billdeg@...> wrote:
> > Here is a pic of the affected area on the board:
> > http://www.vintagecomputer.net/Morrow/wuderbuss_mb_s-100.jpg
> > Bill
> Herb/Anyone else..
> I have a 1977 Morrow Wunderbuss "Thinker Toys" S-100 Motherboard
> blown Zener diode near a 12+V position at the back of the board.Anyone
> have a schematic? I checked Herb Johnson's site, there is nothingfor this
> board listed. I would like to determine the exact type of diode soI can
> replace it.Being on the digest version of the list, I'm a little slow to get
> What would cause a Zener diode to pop?
messages and being disorganized enough that it took a couple of days
to find my Wunderbuss manual, I'm a bit slow to respond...I think
Herb pretty much covered all the relevant points.
All I can add at this point is that the tantalum caps associated with
the voltage regulators on this board are listed as 1 ufd on the
schematic and called out as 20v parts in the parts list.
Certainly no reason not to go with a higher voltage replacement -
these guys tend to provide a common source of entertainment on many
S100 systems and also frequently self-destruct on Heathkit H89
systems. Yet another good reason to avoid leaning over a vintage
system when you first power it up after a long rest.
Always glad to pay my respects to Chairman Morrow,