133 replies to this topic

[Blink Too Fast]

Gday Blinktoofast

 

If you have a multimeter, check the resistance between

+5V rail and ground to see if it shows a short circuit

If it does, it could be ANY chip or part on the 5V rail

Thanks.

 

I do have a thermal camera that plugs into an Android. I don't have an Android.

 

Measuring resistance across all pairs of the 8 pins on the Autostar RJ45 socket, the only closed circuit I find is between pins 2&4 or 7&5 depending which side we count from. Closed circuit is with both polarities. I tried all 56 pair combinations. (7*8=56, or (1+2+3+4+5+6+&7)*2 = 56)

 

Looking at this chart, I can see the same signal on 7&5, so a closed circuit appears normal.

 

I suppose I could look inside the mount for additional shorts.

 

I could plug the Autostar in again, and see if it works now that it has cooled down.

 

eBay has several 497 and 495 listed, so could go that route, too.

Edited by Blink Too Fast, 08 February 2024 - 04:33 PM.

[Blink Too Fast]

Plugged the Autostar in again.

Did not connect the PC again.

To no-one's surprise, the Autostar doesn't magically work.

 

The voltage regulator rapidly becomes burning hot again, so, hmm, is probably working and I now have a surplus of them.

 

No other components are becoming obviously hot.

[OzAndrewJ]

Gday Blink too fast

 

I can see the same signal on 7&5, so a closed circuit appears normal.

Yep, the mount uses a common data line for the motors

and they connect together inside the handset, so they should be short circuit at the connector.

 

I suppose I could look inside the mount for additional shorts.

Thats the hard part, as all parts are in parallel between +5V and ground

so finding the offendor is a problem ( hence the thermal camera trick )

as it could even be a shorted small capacitor.

 

If the VR is becoming hot, and you have more on the way

measure the resitance between V5+rail and ground

Now carefully remove the regulator

re measure the resitance between +5 and Gnd

If it is still short, then there is a damaged component still.

 

Otherwise, can you borrow an android phone for a while ??????

 

Andrew Johansen Melbourne Australia

[Blink Too Fast]

Gday Blink too fast

The VRMs arrived.

So did an Autostar 495 43Ea that I bought on eBay.

Doesn't work with, well, nearly anything, and apparently programmed before Meade made equatorial mode available.

 

Currently updating to StarPatch 43GK, which should also turn it into a 497.

 

 

Updating in progress

23% complete...

[Blink Too Fast]

Well, it works.

And by "works," I mean the 495 is now a 497 with equatorial support, and SharpCap and PHD2 can control the LX90, which seems promising.

 

Can't tell you anything more than that as it's snowing outside.

[BradH]

Andrew I want to thank you.

My RCX400 10” has been sitting for a few years in my observatory with no way to control it. I wasn’t even sure it would still work. The Autostar quite years ago. I bought the Meade wireless controller a long time ago and it quit as well. I bought Meade Stella and used it until the app quit working.

I found your app plugged in the Stella adapter and magic the old scope came to life. I left the observatory roof close to many clouds. Did a one star alignment. Everything seems to work great. I parked the scope. Now. I just need some clear skies.

[OzAndrewJ]

Gday Brad

By died, do you mean you cant read the screen????

If so, you canlreave the handset plugged in and start my app as well.

Set the screen to the menus and then use the real handset

to try and slew the mount etc.

Des the mount respond????

If so, it may just be the LCDS screen in the handset that is dead

and if so, there are now $30 drop in replacements available.

Being an ASII, it may also require a diode to be soldered in to get the contrast working properly

but dozens of people have now done this to get thisr handsets working again.

Andrew Johansen Melbourne Australia

[BradH]

The screen works. Once it gets the GPS done and goes to alignment screen. Non of the buttons are working on the remote.

[OzAndrewJ]

Gday Brad

Are you talking the wireless or wired?????

If you have the wired unit , and can make a simple loopback cable,

there is a self test routine in the handset to confirm if the buttons work.

The normal reason for no button response is

1) The buttons/contacts have oxidised

    You can open the handset and clean the contacts with a soft eraser

    as a quick test

2) The handset is at speed 1, hence the slew keys dont "appear" to work.

 

I must say, i cant remember any time where a handsets buttons have ALL died.

 

Andrew Johansen Melbourne Australia

[BradH]

Wired controller. I will try taking it apart sometime and clean it. Yeah none of the buttons work. If cleaning the contacts.

I do like what I seen with Scope Boss app. Everything seemed to work just fine.

[BradH]

Andrew I will also try having the controller plugged in and have your app set to menu and see if it will work like you said earlier.

I didn’t have it plugged in when I used the app

[Will2007]

Brad,

The issue may be the carbon film on the actual buttons have gone bad.  There is at least one replacement that works great.  I *think* Andrew gave me the contact info last year.

Will

[DAVIDG]

Brad,

The issue may be the carbon film on the actual buttons have gone bad.  There is at least one replacement that works great.  I *think* Andrew gave me the contact info last year.

Will

 You can get both a replacement for the screen for the Autostar 497 and the Autostar II and a repair keypad to replace the original and get all the keys working again from Buttonworx

 

 https://buttonworx.c...rch&s=telescope

 

         - Dave 

[BradH]

Thanks Dave

For info and link.

Just placed an order.

Edited by BradH, 13 March 2024 - 09:47 PM.

[BradH]

I installed the buttonworx today.  It didn’t fix the connector buttons.  None of them worked. The scope got a GPS fix select object came up and that’s it.  I pugged in the Stella and connected to the app and selected the moon.  The scope skewed to moon and controller showed what I was doing on the app.  
 

My controller looked new on the inside.  Not for sure why the buttons don’t work but I have control of the scope again. 

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Edited by BradH, 19 March 2024 - 08:34 PM.

[Will2007]

Brad, if you can wait until early May, I will near my LX200 again (it's in MA) - which uses the same hand-box. If you want, I can take a look at it then, but you would need to send it to me.

I had replaced the "buttons" in my 'hand-box' about a year ago, and it worked just fine.

-Will

[BradH]

Iam in no hurry. It’s working fine the way Iam using it.
I thought the buttonworx membrane would’ve fix the controller. It might be something in the circuit board on the controller. Let me know when you are in Maine.

Thanks for all help.

[OzAndrewJ]

Gday Brad

Its very unusual for ALL buttons to fail.

There are full circuit diags in the LX200 IO groups site

but basically, the buttons are connected in a 5 x 4 grid.

As such, a broken trace would normally take out 4 or 5 buttons

but to lose all buttons means at least 4 traces are damaged.

If you have a multimeter, you could easily test the handset

to see if the traces are OK or not, as your fault is highly unusual

 

Andrew Johansen Melbourne Australia

[DAVIDG]

 The  only thing I see that is common to all the keys is the +5 volts and the PIC that controls them  If the +5  is not present that would stop all the keys from  work. It would be easy to check that with a volt meter. The current limiting resistors might be mounted in one case and if that cracked that would cause the lack of +5 to the keys.

 

                         

                       - Dave 

 

[BradH]

I can get a voltmeter. Once I do how would I check it?

Thanks in advance.

[BradH]

The only thing I couldn’t find continuity was  far right one on the picture. 

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[Will2007]

Brad,

Does the red LED (flashlight) work?  If so, then the +5 is present and the micro is working. If not, do the red LEDs around the display working? If one of the resistors is cracked (they will NEVER burn out at 5 Volts), I can replace it easily as those parts are 1206 size (read: large SMT).  That should show as a row or column of switches not working.

 

-Will

[BradH]

I will have to check when I get it home. As I remember LED seemed to work fine.

[BradH]

No I just remember try the light it didn’t work

[DAVIDG]

 Let review so we  all understand what is going on.  Is it correct that the LCD display in the Autostar II  now work ?  If so when you plug it in does it shows the Meade welcome screen and boots up to a point were it asking for information like Time date and location or the type of alignment you want  etc  etc  ? 

   If so you said none the keys on keypad work even after you have added the Buttonworx over lay ? 

   If everything is true up to this point  then there is either something wrong with the PIC that reads the keys or as I showed on the schematic there is no +5 volts going to them.  To check this you need to measure the voltages going to resistors R33 thru R36  that  and located next to the PIC.   So you measure with a voltmeter from the center pin the voltage regulator which is ground  to the resistors. My guess is the outside of the resistors closest the edge of the circuit board is were the +5 is attached to all of them but measure the inner contacts as well just to be sure.  If you don't measure any +5 at the resistors the problem maybe the via. A via is were the trace on one side the circuit board passes through the board to a trace on the other side to make electrical connection. Sometime these can fail. The fix is to apply some solder to fill it in to remake the connection. or to add a jumper wire to replace the trace. 

 

  Here is a  picture I marked up showing the resistors, via and ground pin on the voltage regulator.  

 

                      - Dave