[TG] ST290 System Block Diagram Review and assistance

[smorast]

Hello Forum Mods/tech support,

Kindly request a review of the attached in reference to the following questions:

Background: System is operational, but have issues with compass heading being incorrect at some points (North and South headings within +/- 2 deg, East and West within +/- 10 degrees) and unable to perform S3 CAL at this point due to the sole remaining ST-290 graphic displays being unreadable ("smoked" screen = unreadable). Only purpose of this graphic display is CAL.

Note: All components are running latest available version of firmware/software.

What alternatives do I have in performing CAL?

Options I see from reading other posts:

A: Obtain a functional/readable ST-290 graphic display and perform S3 CAL (Are these screen repairs still performed by Raymarine?)

B: Replace the ST-290 DPU with an ITC-5 and install new AP control head. How is this done and what will need to be procured in order to calibrate the S3 and each of the 3 pods (wind/speed/depth)? Please include following in reply: Will each sensor (wind/speed/depth) be compatible with the ITC-5? Which AP controls will perform S3 CAL and cal of each pod/sensor? Which are form fit for the size of [censored] left in cockpit from removing the ST1 analog CH wind indicator.

If CAL fails or similar compass issues remain, what do you suggest? Replace fluxgate compass or will new gyro compass work on S3? Could I quickly resolve most of the issues by installing EVO core pack or would I also need to replace drive?

Based on the attached diagram, what are the issues you see and what do you suggest as remedies? If you think that something is connected/powered is cause of heading issues, please point it out. All other systems work very well, but I understand it may need to be modified to be correct, so please point those issues out.

Lastly, really appreciate your time and assistance with helping find most technically viable and efficient solution.

Thanks in advance,
Shane

[Tom - Raymarine - Moderator]

Hello Shane,

If your only problem at this moment is compass heading, I'd just fit a dedicated pilot display (ST6002/7002/8002 were the same vintage as ST290, or p70S/p70RS in the current range.) A p70S or p70RS can be directly connected into your Seatalk1 system via a 3pin-6-pin adaptor cable, e.g. part A06073.

Don't replace the ST290 DPU with an ITC5: they are not equivalent and ST290 cannot calibrate ITC5. Similarly, if the only problem is a small(ish) heading error then don't replace the fluxgate: this isn't a fluxgate fault from the sound of it, and the new fluxgate will still need calibrating.

I think that either the magnetic environment around the fluxgate may have changed over the years (invalidating previous calibration) or the pilot may have lost the previous calibration over the years, so all I think you need is a compass swing from a dedicated pilot display. I wouldn't make any unnecessary changes to that ST290 system whilst it's working, you risk causing bigger issues.

Regards,
Tom