Spartan 3E Starter Kit - Power problem

I have S3E starter kit. I accidentally connect a wrong power adaptor
and two power regulators on the board was burnt. I cannot replace them
because pads of the one of the regulators are under the package. So I
decided to make or purchase a power supply card and connect it to
starter kit. I have checked farnell.com and Linear Technology website
but cannot find anything useful. Are there any power supply cards for
FPGA's? Or any idea how I can re-operate my S3E board?

On Jan 22, 9:44=A0am, Din=E7ay Ak=E7=F6ren <din...@gmail.com> wrote:
> I have S3E starter kit. I accidentally connect a wrong power adaptor
> and two power regulators on the board was burnt. I cannot replace them
> because pads of the one of the regulators are under the package. So I
> decided to make or purchase a power supply card and connect it to
> starter kit. I have checked farnell.com and Linear Technology website
> but cannot find anything useful. Are there any power supply cards for
> FPGA's? Or any idea how I can re-operate my S3E board?

Where would you connect a "power supply card" if there was one?

Repairing a board with burnt components can be difficult, often
requiring an intense effort to pick out the burnt pieces of FR4 that
can be unintentionally conductive.  Even components with a pad
underneath can be removed with a narrow focus heat gun, for instance.
Even if you reflow nearby components, usually they're still in good
shape afterward.  Adding "dams" to block the airflow around more
sensitive parts nearby can help when reworking in this manner.

Do you know if your failed regulators have failed open?  If you try to
wire in another regulator such as a linear.com uModule, you need to
make sure the parts still on board can play nice with the new supply.

On Jan 22, 5:18=A0pm, John_H <newsgr...@johnhandwork.com> wrote:
> On Jan 22, 9:44=A0am, Din=E7ay Ak=E7=F6ren <din...@gmail.com> wrote:
>
> > I have S3E starter kit. I accidentally connect a wrong power adaptor
> > and two power regulators on the board was burnt. I cannot replace them
> > because pads of the one of the regulators are under the package. So I
> > decided to make or purchase a power supply card and connect it to
> > starter kit. I have checked farnell.com and Linear Technology website
> > but cannot find anything useful. Are there any power supply cards for
> > FPGA's? Or any idea how I can re-operate my S3E board?
>
> Where would you connect a "power supply card" if there was one?

PCB has test pins for all voltage levels. So I have an access to
regulated voltage nets on PCB. I will use jumpers.

>
> Repairing a board with burnt components can be difficult, often
> requiring an intense effort to pick out the burnt pieces of FR4 that
> can be unintentionally conductive. =A0Even components with a pad
> underneath can be removed with a narrow focus heat gun, for instance.
> Even if you reflow nearby components, usually they're still in good
> shape afterward. =A0Adding "dams" to block the airflow around more
> sensitive parts nearby can help when reworking in this manner.

Removing them is easy. Hard part is replacing them.

>
> Do you know if your failed regulators have failed open? =A0If you try to
> wire in another regulator such as a linear.com uModule, you need to
> make sure the parts still on board can play nice with the new supply.

What do you mean by "failed open"?
I think you mean passive components on the board should play nice. If
they cause problems, I can remove them too since they will be useless
if the regulator is removed.

Din?ay Ak??ren <dincay@gmail.com> wrote:
(snip)
 
> What do you mean by "failed open"?
> I think you mean passive components on the board should play nice. If
> they cause problems, I can remove them too since they will be useless
> if the regulator is removed.

The two common failure modes for electrical components, especially
semiconductors, are to fail open (open circuit) or fail short
(short circuit).  The latter case is bad news for your FPGA.

-- glen 

On Jan 23, 4:55=A0am, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
> Din?ay Ak??ren <din...@gmail.com> wrote:
>
> (snip)
>
> > What do you mean by "failed open"?
> > I think you mean passive components on the board should play nice. If
> > they cause problems, I can remove them too since they will be useless
> > if the regulator is removed.
>
> The two common failure modes for electrical components, especially
> semiconductors, are to fail open (open circuit) or fail short
> (short circuit). =A0The latter case is bad news for your FPGA.
>
> -- glen

It must be failed short, because regulators draw very high currents.
I wonder why there is no protection circuits. A simple zener would
prevent this accident.