Pansat
9500HDX
Problems
Trimble -
11/6/2014
Updated 10/5/2016 (LNB Power held at 18vdc)
The Pansat 9500HDX
overheating has now duplicated the history of my Pansat 9200HD.
While the 9500 has a much cooler operating ALI M3602 processor (than
the 9200HD’s
ARM Conextant) the attachment of a much smaller heatsink, again, with
an
insulating layer of adhesive (Figure 1) has allowed partial M3602
destruction.
Click on pic to enlarge
Figure 1 - Insulating Adhesive Piece
Its HDMI output
ceased to operate and also the output via component ports began
freezing
intermittently. Either parts of the
M3602 HDMI hardware failed or some of its ball
grid array (BGA)
connections
to
the main-board failed. The component
video began freezing for short moments and got longer and longer.
Unexpectantly, the pressing of a channel change button would unfreeze
it. Scope observation of the HDMI lines
directly from the M3602 showed no activity, eliminating the possibility
of
downstream chips being the cause. Also,
changes in the firmware had no effect.
Figure 2 - Beam for Clamping
Initially
I did not
even consider M3602 overheating, but a finger on the heatsink indicated
it was
pretty hot, and the cpu chip likely much hotter.
The
solution, as for
the older 9200HD*, was to remove the heatsink, (working an Exacto blade
between the chip and the heatsink) and substituting a thin layer of
heatsink
compound for the thick sticky pad.
Continued pressure on the heatsink via a beam keeps it in place,
as can be viewed in Figure 2.
With this change the
freezing of the component video has, to date, stopped.
I am convinced that the makers of these units have yet to learn how to
sufficiently cool
cpu chips.
I also decided
to upgrade the heatsink in my Linkbox 8000HD Local with its PGA (pin
grid
array) attached M3606 cpu chip. Not being BGA attached to the circuit
board the cooling would
be more dependent on the heatsink, yet the size of its heatsink
cooling surface
was much smaller than that on the 9500HDX and the paste pad attaching
it was again
thick. Figures 3
and 4 show the original Linkbox installation and cpu.
Figure 3
- Linkbox
Heatsink
Figure 4 - Linkbox CPU
I replaced that heatsink with one
with far more surface area, again, using a thin layer of heatsink
compound
and a small beam to clamp it to the M3606 chip (Figure 5).
Figure 5 - Improved Heatsink
Hopefully,
these
heatsink changes will end failures due to heat.
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Modification to keep LNB power at 18vdc
rather than going to 13vdc for Vertical Polarity
.
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*http://personal.linkline.com/trimble/pansat