<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p>All:</p>
<p>I have come to the conclusion that my friend's Mercury card has
hardware issues. I wonder if anyone on this list can/will do
troubleshooting/repair or knows anyone who can.</p>
<p><br>
</p>
<p><u>Symptoms</u>:</p>
<p>When first powered up, Mercury seems to work fine, but after a
few minutes, quits working and the relay chatters in sync with
some of the "atypical" LED behavior.</p>
<p>Slow motion imaging tells us that U-15, a 3.3-volt regulator
which goes to a lot of different places on the board, is shutting
down, in sync with the relay chatter. (The LED goes OUT.)</p>
<p>Thermal imaging tells us that U-15 is getting quite hot,
suggesting it is shutting down on thermal overload, not
over-current. It gets hotter than U-15 on <i>either </i>of my
two boards which work.<br>
</p>
<p>Thermal imaging tells us that the FPGA is much hotter than <i>either
</i>of my two Mercury boards.</p>
<p>My Mercury board works in the backplane where his does not. His
acts up in two different Atlas backplanes. The two Atlas boards
have different 12-volt and ATX power supplies.<br>
</p>
<p><br>
</p>
<p><u>Additional information:</u></p>
<p>We have tried loading earlier versions of Mercury firmware and
reloading latest version of firmware to see if there were some
issue there. Only change is the length of time before the problem
starts.</p>
<p>Penelope and Excalibur appear to work fine in his Atlas
backplane.<br>
</p>
<p><u><br>
</u></p>
<p><u>Hypotheses:</u></p>
<p>This is a Mercury issue, not an Atlas or power supply issue.<br>
</p>
<p>There is <i>something</i> going on in the FPGA. <br>
</p>
<p>The higher temperature than on two other working boards for U-15
suggests that U-15 is not prematurely shutting down.</p>
<p><br>
</p>
<p><u>Request</u><u>:</u></p>
<p>Is there anyone around who can troubleshoot, or just replace the
FPGA? I've looked through magnifiers; my eyes are no way good
enough to replace the FPGA. I could do the regulator, but as
above, the data suggests it is behaving as it should.</p>
<p><br>
</p>
<p>Thanks & 73,</p>
<p>Jim</p>
<p><a class="moz-txt-link-abbreviated" href="mailto:wb4gcs@amsat.org">wb4gcs@amsat.org</a></p>
<p><br>
</p>
<br /><br />
<hr style='border:none; color:#909090; background-color:#B0B0B0; height: 1px; width: 99%;' />
<table style='border-collapse:collapse;border:none;'>
<tr>
<td style='border:none;padding:0px 15px 0px 8px'>
<a href="https://www.avast.com/antivirus">
<img border=0 src="http://static.avast.com/emails/avast-mail-stamp.png" alt="Avast logo" />
</a>
</td>
<td>
<p style='color:#3d4d5a; font-family:"Calibri","Verdana","Arial","Helvetica"; font-size:12pt;'>
This email has been checked for viruses by Avast antivirus software.
<br><a href="https://www.avast.com/antivirus">www.avast.com</a>
</p>
</td>
</tr>
</table>
<br />
</body>
</html>