Alarm caused by PMA 7000M-S

[N81FM]

Hi,

Have any of you ever had an alarm caused by the PMA7000M-S on the Ovation? As soon as i switch ON the master radio, the alarm starts.

If i press the bottom right corner of the PMA the alarm will stop and then restart when i stop pressing. I removed the PMA, cleaned the contacts, checked the connectors at the back of the rack, everything looks good.

I've removed and reinstalled the PMA again and again, nothing changes !

None of the breakers (Gear, vac, stall, A/P ) stop this alarm !!!

What causes this alarm ? How to fix this problem ?

Jean-Claude 

[M20S Driver]

I had the exact same problem for a while and it was very intermittent.  The Main PCB in PMA was replaced to fix it.  

[FoxMike]

I had a problem once while flying my Bravo.  I started hearing "low fuel" loudly over the headphones.  The warning would not silence.  I had just added fuel so I was not concerned about the fuel but trying to communicate with the tower while the warning was blasting was a hassle.  Turns out Mooney had PS Engineering provide audio panels with voice alerts.  No one could assure me that would happen again so I removed the input wiring from the audio panel.  The original audio panel was a 7000.  I have since replaced it so I only had the problem once.  Mooney had the sound cards installed in the PS 7000 but never activated the system.  Good thing,  it is really a pain.  If you think you might have an audio panel with the warning system in it, I would suggest you have the radio shop remove the wires (inputs) from the panel so you will not have a surprise.

Edited September 13, 2020 by FoxMike

[LANCECASPER]

The PS 7000BT is a slide-in replacement for your audio panel and adds Bluetooth. I wouldn’t spend any money fixing a 20 year old audio panel.

https://www.ps-engineering.com/pma7000bt.shtml

@Mscheuer

[Aerodon]

By 'alarm' do you mean a tone sound or an aural alert?  Such as 'check engine' or 'low fuel'.  These are triggered by your OEM 'switches', and there should be an 'acknowledge button' somewhere to turn it off.  I would guess if you are in turbulence, the low fuel could come on repeatedly?

 

Aerodon

[carusoam]

Mark S is our key contact at PSE...

Lance has already turned Mark’s notification light on...

Go MS!

Best regards,

-a-

[N81FM]

If the problem is with the PCB and it probably is, I think you are right 20 years of service is already not bad.

I'm going to ask a friend of mine who has an Eagle with the same PMA7000 to replace mine and see what happens.

Thanks to all

 

[N81FM]

this is an aural alert like the stall warn or the Gear warning

[Mscheuer]

On 9/13/2020 at 3:38 AM, N81FM said:

Hi,

Have any of you ever had an alarm caused by the PMA7000M-S on the Ovation? As soon as i switch ON the master radio, the alarm starts.

If i press the bottom right corner of the PMA the alarm will stop and then restart when i stop pressing. I removed the PMA, cleaned the contacts, checked the connectors at the back of the rack, everything looks good.

I've removed and reinstalled the PMA again and again, nothing changes !

None of the breakers (Gear, vac, stall, A/P ) stop this alarm !!!

What causes this alarm ? How to fix this problem ?

Jean-Claude 

Your unit was sold to Rheinland Air Service on Feb 15, 2002.

Option 6 was for our Mooney OEM, it has the built-in marker but uses the marker lamps on the instrument panel.

Your unit does NOT have option 1, which was our aural warning system, so what ever you are hearing, it is coming from a device that is hooked up, probably to an unswitched unmuted input.

Hope this helps.

By the way, there is a slide-in replacement you should consider if you ever want to have Bluetooth integrated, it is also 16 year newer design.

http://ps-engineering.com/pma7000bt.shtml

Mark Scheuer

PS Engineering

[carusoam]

Great support, Mark!

Best regards,

-a-

[N81FM]

sorry but i don't understand why in this case when we remove the PMA 700 the alarm stops and as soon as we plug it again in the rack it starts again !

[M20S Driver]

It was the same on my plane.   The tone was generated by the PMA700 box.  Andre at Executive Autopilot added an extender cable to connect the unit for troubleshooting and noticed the tone was coming and going based on moving or shaking the box.  He did not find any contact problems so he replaced the main board and the face plate, but kept the rest of the boards in the unit.

[N201MKTurbo]

It isn't an alarm, it is one of the internal amplifiers oscillating.

[N81FM]

Thanks M20S Driver, I actually think we ran into the exact same problem.

[M20S Driver]

46 minutes ago, N201MKTurbo said:

It isn't an alarm, it is one of the internal amplifiers oscillating.

you are correct,  as usual