Walter,
Thanks very much for your response. I think you are right.
I took a closer look at the card and saw two traces that were supposed to be
connected to the disks around the mounting holes. One leads to R38 and the
other to an 8-pin chip next to the PC/104 connector.
So I re-installed the metal standoffs in the mounting holes and connected them
to the negative lead on the power connector, which then (re)supplied ground to
R38 and the 8-pin chip. I powered on the board and it came up just fine.
I repeated this process with the three other 'failed' boards, and they also
came up just fine.
In summary, drilling out the mounting holes is a bad idea, but apparently not a
fatal one.
BTW: It is probably worth mentioning the two symptoms of this problem, lest
anyone else stumble into it like I did. First the boot process hangs for about
30 seconds just after the first asterisk after the Redboot message. The second
is that, once the boot process completes, the Ethernet interface is inoperable.
Other than that, the board operated nominally. Or rather, the parts of the
board we were using operated nominally. I don't know, for instance, if the
PC104 was operable, since we are not using it.
Thanks again for your suggestion.
jw
--- In Walter Marvin <> wrote:
>
> Drilling out a ground pad per se probably did not do any damage. The flexure
> or vibration on onther part of the boards may have.
>
>
>
> ________________________________
> From: jywmpg <>
> To:
> Sent: Sunday, March 11, 2012 8:26 AM
> Subject: [ts-7000] Boring out the mounting holes on a TS-7260 - Bad Idea?
>
>
> Â
> Let me preface this my saying that I am chagrined to have to ask the
> following:
>
> Will boring out the mounting holes on a TS-7260 to 9/64" cause it to fail?
>
> I have several of them that have failed in the last few days with the same
> odd errors and find that the only thing they appear to have in common is that
> an industrious, if ill-trained, employee drilled them out to accommodate the
> available standoffs.
>
> After discovering this, I ran a continuity check between the negative pin on
> the power connector and the metal disks surrounding each the mounting holes
> and found no continuity. A similar check on a working board showed
> continuity between all five points (i.e. all mounting holes are connected to
> ground).
>
> So, is that enough to render a board inoperable? And if so, can the boards be
> fixed by re-establishing ground to the outer, and presumably inner, board
> layers?
>
> Red Faced
>
> jw
>
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