Altrak will not engage

[degratec]

I have an Altrak TS with a DSP-B servo installed in my RV4. The system is linked to the Digitrak 2.5 with Garmin 155XL connected. Altrak installation took place in 1994 and worked perfect for about 240 flight hours. Today, after a 3 months winter break, I'm not able to use ALT mode anymore. Digitrak works fine. While powering up, the ALT-light flashes for ca. 6 seconds (sometimes only 3 seconds) and turns black. When trying to engage ALT, nothing happens! What shall I do for troubleshooting? Kind Rgds & thank you, Max.

[TrutrakTech]

Hi Max,

The VS control knob on the Altrak VS must be in it's 0 position for the Altrak to engage. Check the voltage on pin 8 of the Altrak with the Master on and the VS knob at 0. It needs to be 2.5V. Let me know what you find. Thanks!

[degratec]

Hi Lucas,
I dont't have the VS version, it's the original Altrak....

[TrutrakTech]

Ok, sorry about that. When you said Altrak TS and DSP B servo, I thought you meant the Altrak VS as that's the only one that would have a DSP B servo.

Check the voltage on pin 3 of the Altrak while you cycle the engage button on and off. It should cycle between an open and ground. Let me know what you find.

[degratec]

Thank you Lucas! After working some days away from homebase, I went to the hangar today to check for pin 3 voltage. What a surprise, Altrtak is working as it ever did! That's why I decided not to open the panel for toubleshooting. Anyway, thanks for your kind support, I will be glad to get back to you should problems arise again..... Best regards, Max.