PMS GTN 750 not turning on without bat/and power

ZenIT_SWE

With power switch to off and the avionics switched on my GTN 750 doesn't turn on. I have the WTT mod installed and haven't tried without it.

Laurreth

@zenit_swe The GTN is attached to the avionics 1 bus; if you have that mapped to a switch, like for example on the Honeycomb Alpha, you'll need to turn it on. It should then work with the radio switch.

ZenIT_SWE

I can't find how to turn on avionics 1 bus. I've tried with AVIONICS_MASTER_1_ON but that didn't work. :-/

Laurreth

It should only be an issue if you have a button bound that holds it off I think.

Randolf

I can confirm that the PMS50 GTN750 doesn't turn on with the "radio master" switch without turning on the battery/GPU switch. If I switch out the GTN750 for GNS530, the 530 works as expected, turning on with "radio master" switch even without battery/GPU switched on.
Tried PMS50 GNS730 with and without WTT mode, same result. I mean the WTT mode package from here https://pms50.com/msfs/aircrafts/
Not sure where the problem is, if with PMS50 or Black Square addon.

JetNoise

@randolf
@ZenIT_SWE

it will work with Crashbar up, Radio Master On. From the VC of course.
For external controls idk.
Make sure no other Hardware controls are interfering
HC Bravo is known for that ....

Oliver

Randolf

@jetnoise does it really work with PMS50's GTN750 addon for you? Yes, I noticed that you also need the crashbar up (should it really have an electrical switch?).
As I said, I can make it work with the MSFS native 530, there I can use it without battery or GPU power, with just radio master (and the crashbar up), but can't make the same setup work with GTN750 addon. And I also see that the indicator light just above the radio master switch lights up, but the 750 screen just stays black, until I also switch on the battery or GPU :(
I don't have any external hardware that would interfere with the power settings of the aircraft.

JetNoise

@randolf Are you on the latest PMS GTN ?
and have the WTT mod from his website ?
https://pms50.com/fs2020/gtn750/aircrafts/pms50-gtn750wtt-aircraft-bksq-tbm850.zip

JetNoise

@randolf

Crashbar: Electrical Circuit Page 75/76 in the manual . RTFM ;-) ;-)

Randolf

@jetnoise yes, I have the latest version of PMS GTN750 v2.2.4 and as mentioned in my previous post, tried with and without the WTT mod, same results.
From the electrical schematic in the BKSQ TBM850 manual ( https://dxhb0it26is40.cloudfront.net/manuals/BKSQ_TBM850Manual.pdf ), page 75, I can see that normally the GPS is powered by "essential radio bus 1", but without main or ESS bus power, it should probably be powered by "battery bus" and "ground clearance unit", top left of the schematic. Maybe that connection is not checked in the GTN750.

JetNoise

@randolf

Had to finish my flight first ...
Here you go ...

Oliver

Randolf

@jetnoise thank you for the confirmation that it shoud work. I'll keep looking.

ZenIT_SWE

Hmm, I wonder if it's a livery thing?

JetNoise

@zenit_swe
Could be a livery, could be an outdated wtt mod or simply a corrupted install...

Sergio

Same here...GTN750 does not turn on with the radio master switch on and crashbar up, however it works with the GNS530 (using default livery)

@randolf said in PMS GTN 750 not turning on without bat/and power:

I can confirm that the PMS50 GTN750 doesn't turn on with the "radio master" switch without turning on the battery/GPU switch. If I switch out the GTN750 for GNS530, the 530 works as expected, turning on with "radio master" switch even without battery/GPU switched on.
Tried PMS50 GNS730 with and without WTT mode, same result. I mean the WTT mode package from here https://pms50.com/msfs/aircrafts/
Not sure where the problem is, if with PMS50 or Black Square addon.

Laurreth

I don't think that block diagram of the electrical system is that great. As it is, you need to set the ESS BUS TIE to EMER, and the radio master will turn on a GTN750 and the transponder when the crash bar is up. But it appears to be behaving wrong with the 750, maybe that is hooked up to the wrong bus.

(edit) Looks like it's on the correct circuit, same as the other COM1 units.

paulwareing

From the discord...

Sergio

@paulwareing Great...now it works :clapping_hands: :clapping_hands:

Randolf

@paulwareing yes, thank you for relaying this! This works indeed.
Now I can use electronic checklists on the GTN750 before powering up the whole craft.

Voice of Reason

Yes to confirm, a message from the developer:

'This was actually caused by a single typo. I've fixed it for the next update, but if you want to fix it yourself, change the following line in the panel.xml file.'

Hope that helps