Can an intermittent audio and video signal be fixed?

why not you use a normal AV cable
instead of hdmi cable

Not possible with that setup

if you have a coax digital out on your tv, why not use that, you have coax, optical, and hdmi inputs on your reciever, but the easiest, low cost way is the coax

you can connect Yamaha YST SW800 at the back of your receiver

( label =subwoofer )

http://uk.yamaha.com/en/products/audio-visual/speaker-systems/subwoofers/yst-sw800_black__u/?mode=model

Settings are not the source of intermittent problems.

"Signal loss" is indicated WHERE? So what's going on upstream at the source? ITS cables are a part of this.

My $.02... I never route any signal unnecessarily to or through a device that doesn't enhance or consume it. Hence, my BEST video from each of my several video sources goes directly to my TV/monitor and my BEST digital audio from all sources goes directly to my AVR.

No problems.

Hi, Yamaha audio-video receivers are equipped with a variety of connecting jacks for hooking up different types of electronic equipment. Component AV cables are typically used for hooking up the receiver to a cable TV box. Component cables can also be used to connect the Yamaha receiver to an HDTV, although a High Definition Media Interface (HDMI) cable offers a simpler connection if the receiver is equipped with HDMI (all HDTV sets are equipped with the distinctive, six-sided HDMI jack). The connections should take less than five minutes.

Instructions

Things You'll Need:

* 2 sets component AV cables
* HDMI cable


Check the back of the Yamaha receiver to determine if HDMI is available. The six-sided jack contains 19 holes set in three rows. If the receiver is equipped with an HDMI Out port, use an HDMI cable to connect to the TV by inserting the plug straight into the jack with the wider end turned upward.


Insert the red, green and blue plugs on a set of component AV cables into the Video Out jacks on the cable TV box, matching the plug colors to the jacks.


Connect the plugs on the other end to a set of Video In jacks on the back of the Yamaha receiver. Make a note of which jacks are used for the connection. Each set of jacks is labeled on the receiver.


Insert the audio plugs on the component cables into the Audio Out jacks on the cable box, using the white plug for the left channel and the red plug for the right.


Attach the plugs on the other end to the Audio In jacks on the Yamaha receiver.


Use a second set of component AV cables to connect from the AV Out jacks on the Yamaha to the AV In jacks on the HDTV only if an HDMI cable was not used.

Receiver does support 3x component inputs and one component output. Both these can carry only video signal, not audio. So you have to connect audio separately, either stereo via analog 2x RCA connectors and digital SPDIC via optical (2x) or coaxial (1x) cable.

I need a connection Diagram for the RX-V465 Yamaha receiver

I have the same receiver... You can try pressing the Option button and choosing Signal Info to see what audio signal the receiver sees and if that changes over time. Maybe the cable box is not outputting according to specifications... TV can live with that, but receiver maybe can't.
You can also try to connect the cable box via SPDIF cable (optical or coax) to see if it helps or not.