Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Meade LX85 ( Crash test dummies required )

  • Please log in to reply
12 replies to this topic

#1 OzAndrewJ

OzAndrewJ

    Gemini

  • *****
  • topic starter
  • Posts: 3,076
  • Joined: 30 Nov 2010

Posted 05 October 2019 - 12:04 AM

Gday All

Is there anyone out there with an LX85 that knows how to use a multimeter to measure pins in a port and is willing to do so? ( A simple unpowered continuity test will be OK for the +12 and grounds )

A user recently plugged in a StarGPS lump and it got fried.

Also, part of the users PCB blew, but on measuring the voltages in the Aux port ( which supplies power to the lump ), he is registering that the ground and +12V pins are swapped relative to all other mounts.

I have attached a piccy of a std Meade control panel and what pins are +12V and what are ground for the Aux port.

If someone can check their port on the LX85 and confirm it is either opposite or the same as what i have attached, it would be most appreciated.

Andrew Johansen Melbourne Australia

497 Panel Front.jpg


Edited by OzAndrewJ, 05 October 2019 - 04:06 PM.

  • EdIII likes this

#2 OzAndrewJ

OzAndrewJ

    Gemini

  • *****
  • topic starter
  • Posts: 3,076
  • Joined: 30 Nov 2010

Posted 10 October 2019 - 04:10 AM

OK if no one has the ability to test the pins, do any LX85 owners have the ability to open the housing

and take a detailed close up piccy of the circuit board where the connectors are

( similar to circled area in attached )

Andrew Johansen Melbourne Australia

LX85 PCB sockets .jpg


  • EdIII likes this

#3 Geo.

Geo.

    Vendor - Nexstar Parts

  • *****
  • Vendors
  • Posts: 5,192
  • Joined: 01 Oct 2008
  • Loc: Upstate NY

Posted 27 October 2019 - 03:46 PM

That looks like it may have been a tant cap between the 12+ trace and the ground plane. It would not have liked reversed polarity. 



#4 OzAndrewJ

OzAndrewJ

    Gemini

  • *****
  • topic starter
  • Posts: 3,076
  • Joined: 30 Nov 2010

Posted 27 October 2019 - 04:09 PM

Gday George

The user cleaned up the board and it was an inductor

Basically, StarGPS pinches +12 and ground via the aux port and drops it to 5V via a built in regulator

When the user plugged in the StarGPS

The 12V from the Aux went into the ground of the reg, which was tied to the rs232 ground in the hbx

This was tied to the power panel ground via the Hbx cable and ( luckily ) the first thing to blow was the inductor

 

Meade have now confirmed that both the LX65 and LX85s have their Aux ports wired mirror image

so no one should plug any legacy items into the port.

StarGPS has developed a new cable specific for the LX65/85 and it sounds like Meade are revising the boards, but that leaves a lot of time bombs out there.

 

Andrew Johansen Melbourne Australia


  • EdIII and NickInSac like this

#5 EdIII

EdIII

    Vostok 1

  • *****
  • Posts: 185
  • Joined: 30 Oct 2017
  • Loc: Florence, SC

Posted 29 October 2019 - 11:55 AM

I ran into that problem with my LX65.  It burned up an LNT module and would not work with my GPS. How could such an error get out of their doors unnoticed? Did they not try the aux port on something??

 

Ed


Edited by EdIII, 29 October 2019 - 11:57 AM.


#6 OzAndrewJ

OzAndrewJ

    Gemini

  • *****
  • topic starter
  • Posts: 3,076
  • Joined: 30 Nov 2010

Posted 29 October 2019 - 04:44 PM

Gday Ed

I am assuming you are the same Ed who is corresponding with Chris ar StarGPS

If so, did you actually smell anything in the mount???

The LNT may have fried with simple reverse polarity

but by plugging in the StarGPS, it allows 12V from the Aux port to be put into the ground lines of the Hbx via the rs232 cable

This then allows a ground loop inside the mount which "may" have burnt out a chip in the mount.

I would be asking Meade to replace your LNT, and also advising whoever you sent the mount back to

to check it for damage.

Andrew Johansen Melbourne Australia


  • EdIII likes this

#7 EdIII

EdIII

    Vostok 1

  • *****
  • Posts: 185
  • Joined: 30 Oct 2017
  • Loc: Florence, SC

Posted 29 October 2019 - 06:24 PM

Hello Andrew,

 

Yes, I have communicated my experience to Chris. Too much trouble to ask Meade about the LNT. I used the plastic parts to repair one that had physically broken plastic, so no big deal. My GPS still works, so no damage there. I smelled something in the mount, but did not look any further and that is known by all concerned. Really like the 65. I just want to get one after the corrections are made.

 

Ed



#8 Geo.

Geo.

    Vendor - Nexstar Parts

  • *****
  • Vendors
  • Posts: 5,192
  • Joined: 01 Oct 2008
  • Loc: Upstate NY

Posted 30 October 2019 - 10:54 AM

Dyslexic Designs. Inc. That's the kind of mistake I'd make=8)   


  • EdIII and NickInSac like this

#9 Geo.

Geo.

    Vendor - Nexstar Parts

  • *****
  • Vendors
  • Posts: 5,192
  • Joined: 01 Oct 2008
  • Loc: Upstate NY

Posted 02 November 2019 - 09:05 AM

Ed I break up a lot of mounts and always debate whether to store any of the plastic. It doesn't help when people say they found the stuff useful and I have to weigh that into my decision. Where am I going keep all the d**n stuff??lol.gif


  • EdIII likes this

#10 EdIII

EdIII

    Vostok 1

  • *****
  • Posts: 185
  • Joined: 30 Oct 2017
  • Loc: Florence, SC

Posted 02 November 2019 - 02:03 PM

lol.gif lol.gif lol.gif

Ed I break up a lot of mounts and always debate whether to store any of the plastic. It doesn't help when people say they found the stuff useful and I have to weigh that into my decision. Where am I going keep all the d**n stuff??lol.gif

 

 

lol.gif



#11 Kebino

Kebino

    Lift Off

  • -----
  • Posts: 6
  • Joined: 20 Nov 2019

Posted 18 December 2019 - 01:04 AM

StarGPS.ca has a crossover cable for this issue. It is called GPS-ASTARX as opposed to the regular GPS-ASTAR. 

The cable is specifically made to solve this problem.

also stated on their Website is that later models of the LX65 have the aux ports properly wired. A properly wired LX65 will have a white dot painted or affixed to the housing near the aux port.

That’s all I know, I’ll leave it the more experienced members to go into detail.

PS- I have a LX65 6 ACF in transit to my home as I write this, hopefully it will be here by Friday.

 

https://stargps.ca/manual.htm#meade497


Edited by Kebino, 18 December 2019 - 01:06 AM.


#12 carolinaskies

carolinaskies

    Surveyor 1

  • *****
  • Posts: 1,861
  • Joined: 12 Dec 2014
  • Loc: Greenville SC

Posted 18 December 2019 - 04:04 PM

StarGPS.ca has a crossover cable for this issue. It is called GPS-ASTARX as opposed to the regular GPS-ASTAR. 

The cable is specifically made to solve this problem.

also stated on their Website is that later models of the LX65 have the aux ports properly wired. A properly wired LX65 will have a white dot painted or affixed to the housing near the aux port.

That’s all I know, I’ll leave it the more experienced members to go into detail.

PS- I have a LX65 6 ACF in transit to my home as I write this, hopefully it will be here by Friday.

 

https://stargps.ca/manual.htm#meade497

Thankyou for the update!



#13 Kebino

Kebino

    Lift Off

  • -----
  • Posts: 6
  • Joined: 20 Nov 2019

Posted 18 December 2019 - 11:43 PM

Thankyou for the update!

Glad to help. I’m just happy the StarGPS people are on the ball and made a cross-over cable.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics