Il giorno giovedì 19 aprile 2012 11:59:19 UTC+2, IanM ha scritto:
XPOSTED sci.electronics.repair, rec.boats.electronics,

rec.boats.cruising (due to declining traffic and difficulty of topic)



Hi guys,



*** Background ***



I'm trying to fix an Autohelm ST50 Compass display Z136 (Black, red

trim, round Seatalk connectors, but serial sticker inside says "Raytheon

Marine) that continuously pulls down the Seatalk bus. It otherwise

appears to be working though I haven't tested it with its fluxgate

transducer.



I need it to add a remote sensor for heading reference to a ST2000+

tiller pilot + other Seatalk instruments due to deviation at the tiller

that cannot be economically eliminated. There is no budget for new

replacement, its fix it or do without as this will be a 'shoestring'

upgrade if I succeed. For the curious, this is for a 26' yacht (long

keel Bermudan sloop).



*** Model ***

Autohelm ST50 Compass display Z136

(Black, red trim, round Seatalk connectors, but serial sticker inside

says "Raytheon Marine. May actually be from the ST50+ range)

PCB marked "3015-076 ISS E".



**** Symptoms ***

Does not respond to Seatalk commands (Tested with L0 - L3 illumination

commands), does not transmit Seatalk data, Jams bus preventing

communications between other working instruments.



Yellow wire (Seatalk data I/O) is permanently low when display is

powered but is Hi-Z when un-powered so not a direct short.



No signs of any data at all (on a scope) while cycling illumination level..



No evidence of water intrusion, but possibility of mechanical shock

damage. (cracked mounting pillars in housing successfully repaired)



*** Troubleshooting ***



As above + data I/O wire traced to pin 21 of 24 pin SOIC IC:



AUTOHELM

9410RLA80

RT C 9737



*** Help Wanted ***

Any or all of:



Schematic for this specific display.



Schematic for any instrument in the same general series with a round

analog dial.



Schematic for any instrument using the same I/O chip.



Source of 9410RLA80 chips and/or pinout info (though it may well be the

MCU driving it).



Similar displays for spares or same for use*.



Any other troubleshooting help/support you can think of!



* Free is best - can pay P&P. Cheap is next best. If you want typical

dealer markup I would need fair to good condition fully working with a

warranty. PLEASE CONTACT BY EMAIL - Address + de-munging instructions

in Sig below.



*** Experience ***



20 years of analog and digital component level repair work +

microcontroller experience. I have hardware and software to monitor and

decode Seatalk messages and have the usual equipment and tools of a

small repair shop.



Thank you for your attention.



Regards

Ian.



--

Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)

ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk

[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:

The problem is on the 9410rla80 that is a raitheon chip called ASIC,no more longer user on our devices. The chip provide data in out for the processor, and is in general a common interface for the "outside" world. I believe that now the only way is to take away from an old instrument(like the ones with the needle mecanically broken o frozen but with seatalk ok)or request to Raymarine Portsmouth....
Hope I help you...