KX155 Not transmitting?

[XXX]

Hey guys, my KX 155 does not seem to be transmitting. Started out as intermittent and now seems like nothing at all. I can still receive com and nav just fine. The "t" lights up when I push to talk but Tower can't hear me. Audio panel is a kma 20. Has anyone been through this? Any suggestions other than checking the RCA connectors?

[EricJ]

4 minutes ago, Chupacabra said:

Hey guys, my KX 155 does not seem to be transmitting. Started out as intermittent and now seems like nothing at all. I can still receive com and nav just fine. The "t" lights up when I push to talk but Tower can't hear me. Audio panel is a kma 20. Has anyone been through this? Any suggestions other than checking the RCA connectors?

Can you be heard through a different comm?   If so, then it's not your mic or jack and probably not the audio panel.  If you can receive okay on that comm, then it's unlikely to be the antenna or cable or their connections.   Sounds like maybe the power amp in that comm unit has failed.

 

[XXX]

2 minutes ago, EricJ said:

Can you be heard through a different comm?   If so, then it's not your mic or jack and probably not the audio panel.  If you can receive okay on that comm, then it's unlikely to be the antenna or cable or their connections.   Sounds like maybe the power amp in that comm unit has failed.

 

Eric, Thanks for the reply. Yes com #2 works (the old KX170B indestructible).

[EricJ]

One other thing might be mic connections from the audio panel to the errant comm unit.

 

[Yetti]

Might just want to reseat the KX 155 and the audio panel.  Requires a small allen wrench

[N201MKTurbo]

Mine does that when it gets real hot. I'm upgrading my avionics and will be putting in a cooling fan.

[wcb]

Mine did this as well... Sent it out to Butler avionics... They worked two different times on it and finally said it needs a new board which really means it is doa ... Apparently the older ones had leaky parts that after almost 40 years of service just kills the controller board .... If yours is like mine it means it is time for either a referb 155 (about 2k) or wait on the tkm that comes out later this summer and will be a simple plug and play type option for about $3700. Of course could be time for that Garmin 650 you have always wanted.

[neilpilot]

Before you send your KX155 out, maybe you know someone who will allow you to do a quick and temporary swap?  That maybe the easiest way to determine if it's the unit or other factors.  If you were closer to Memphis, I would be willing.

For repairs, I recommend Bevan Rabell in Wichita

[XXX]

14 minutes ago, neilpilot said:

Before you send your KX155 out, maybe you know someone who will allow you to do a quick and temporary swap?  That maybe the easiest way to determine if it's the unit or other factors.  If you were closer to Memphis, I would be willing.

For repairs, I recommend Bevan Rabell in Wichita

Neil, yes I thought of that. I'm fairly certain that I can find someone to swap out with me for testing and it sure beats crawling behind the panel to check connections first. 

 

21 minutes ago, wcb said:

Mine did this as well... Sent it out to Butler avionics... They worked two different times on it and finally said it needs a new board which really means it is doa ... Apparently the older ones had leaky parts that after almost 40 years of service just kills the controller board .... If yours is like mine it means it is time for either a referb 155 (about 2k) or wait on the tkm that comes out later this summer and will be a simple plug and play type option for about $3700. Of course could be time for that Garmin 650 you have always wanted.

Thanks wcb, yeah the tkm looks promising. I'm about ready to take my instrument check ride so I don't want to reconfigure with a new gps until after I'm rated. The gtn 650 looks like its in my future though. 

 

3 hours ago, Yetti said:

Might just want to reseat the KX 155 and the audio panel.  Requires a small allen wrench

Yetti, Excellent point and easy, will do.

N201MKTurbo, the weather has been hot and humid lately, I do have a cooling fan though. Seems plausible that heat could have taken it out.

2 hours ago, N201MKTurbo said:

Mine does that when it gets real hot. I'm upgrading my avionics and will be putting in a cooling fan.

[XXX]

On 6/22/2017 at 6:42 PM, Yetti said:

Might just want to reseat the KX 155 and the audio panel.  Requires a small allen wrench

That did it. Thanks Yetti!

[Yetti]

Works on IBM mainframes too