Dash instrument cluster works intermittently

This is one guy's advice: Replace the speedo head, that should take care of the problem."

This site is also interesting because the guy said
General Motors cars had instrument cluster problems from 2003 through 2006. When I researched instrument cluster problems on the Internet what I found raised concerns in me. Many of those vehicles had problems that began with the instrument cluster, but eventually led to the engine refusing to start.
(an electronic instrument cluster, digital instrument panel or digital dash for short, is a set of instrumentation, including the speedometer, that is displayed with a digital readout rather than with the traditional analog gauges. Many refer to it simply as a digital speedometer.)

http://www.instructables.com/id/Erratic-Instrument-Panel-on-GM-Cars/

Hi, this is a pretty common problem on these Silverado instrument clusters. We can repair it for you, click here to learn more about these silverado instrument cluster problems: Dr Speedometer Instrument Cluster Repair Speedometer Repair Guage...

check all motor to body ground straps and all wiring harness to body ground straps.
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you have to remove most of the dash then remove cluster from dash they attach threough rear of board

Sounds like an intermittent loss of power to the instrument cluster to me. Remove the instrument cluster and inspect the electrical connectors on the back of the cluster.

You will have to remove the upper dash panel to get to the instrument panel.

sounds like the instrument cluster is failing or you have a loose wire issue. The dash will need be opened up to inspect the connector for proper voltage.
Modulemaster.com can rebuild the cluster but the car will out of service for a week or 2. This is just an option over the high price the dealer will want.

Here you go. Under hood fuse block
Ign. Fuse E
and
ipc/dic
both fuses are 10 amp
I hope this helps. Take care.

replace the circuit board in the cluster.

Removed the dash bezzle and low and behold there were the screws to remove the dash cluster