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
"insulating"
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.

beam
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.

original
exposed
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).

Altered Heatsink
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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LNB Power

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*http://personal.linkline.com/trimble/pansat