29 replies to this topic

[Andy@56]

Hi,

 

I have two Autostars with the partially functional displays.  An effective workaround is to use the "Hand Control Panel" function in AutoStar Suite.  It is found under "Telescope" in the main menu.  This acts like a terminal emulator for the Autostar with a display.  I can use the keypad on the autostar and the display in Autostar Suite reads correctly.  I use a small tablet computer with the Meade interface cable.  This is not a perfect fix because it reduces your portability, but it works and confirmed for me that my boxes are functional and that the problem is most likely the display. 

 

One nice extra feature in the AS Suite function, if you have an electronic focuser, is that focus in and focus out buttons are included in the emulator, so you do not have to press and hold the mode button to access the focuser.

 

Andy

 

Update:

 

Yesterday, I received a new display for the Autostar.  Google search "MHS50747-24AG" and you should see this posted in ebay.  I ordered two and replaced the displays in both Autostars.  They cost $19.99 each.  After the installation, both units now work perfectly.  The only difference is that the new displays have silver reflective backing, so the display is now black on gray, instead of the nice luminous red in the original.  But they fit perfectly and you can still easily read them in the dark.  When installing, use your thumbnail to carefully lift the left and right clips holding the display in place.  Do not try to pull it out.  When you slide the new contact strip in, make sure to re-seat the clamps.

 

One note of caution: You might be tempted to remove the silver reflective backing.  I do not recommend this.  The original Meade part has a red/amber translucent glass filter to allow the red LED light to illuminate the letters.  I think this may be a polarizing filter.  So if you remove the silver reflective tape from the new unit, you will not see the letters when installed.

Attached Thumbnails

• 
• 

Edited by Andy@56, 15 June 2021 - 08:22 AM.

[scriptorron]

Many thanks to the people here in this forum. Since 2 weeks the AutoSTAR #497 of my Meade LXD55 displays garbage. With the help of this forum I could find the error reason: it is the display. I measured the protection diodes of the display controller and found 13 of the 14 digital signals broken. It seems to me the flexible cable delaminated from the LCD glass. Than I swept a solder pen with ~230°C  (temperature regulated!) over the area were the flexible cable is connected to the glass. That made the display working again for 2 days

 

Unfortunately my AutoSTAR has the old hardware version. The display MHS50747-24AG has a communication protocol which is not used anymore in modern alphanumeric LCD displays. So there is no direct replacement with a modern one.

 

Luckily the AutoSTAR still can be remote controlled. The original Meade software is very old and does not work together with ASCOM. Therefore I made my own remote control GUI with the same features as the old Meade remote control. But it uses ASCOM to communicate with the telescope and allows other software (autoguider, Stellarium) to be connected at the same time. You can download it here:

https://github.com/s...AutoSTAR_remote

 

It needs the ASCOM driver from here:
https://bitbucket.or...eadeautostar497

 

I hope it will help others too.

[OzAndrewJ]

Gday Scriptorron

The display MHS50747-24AG has a communication protocol which is not used anymore in modern alphanumeric LCD displays. So there is no direct replacement with a modern one.

If it is the 14wire unit, then the "protocol" used is pretty standard, but the wiring order is reversed for 2 pins

( ie contrast and ground are swapped  IIRC )

Recently a user found a very cheap larger unit that works but needs a new printed housing to fit it.

Another user found a true drop in replacement by Formike, and they do work but may need tweaking

of the contrast voltage circuit. They also cost a lot when you add shipping

Just search the forum for "Formike" to get hits on these

 

Andrew Johansen Melbourne Australia

[scriptorron]

@OzAndrewJ
Thank you for the hint. Unfortunately my AutoSTAR is the old design with the 24 pin display. As far as I know the display has a Seiko Epson SED1233DGB controller which is compatible to the S1D12303. Both chips are not in production anymore. Newer alphanumeric displays have other controller with different commands. For instance the “cursor home” command has a complete different encoding than all modern displays I found. Not to mention differences in the character sets. The only compatible display seems to be the DMC-50747NF-AK (I found that also here in that great forum). I would favor this display over the original MHS50747-24AG because it uses a different technology for the flexible cable. But it seems no one on earth sells it.

On ebay is someone in Texas who sells the MHS50747-24AG. Shipping to Europe is very expensive. I ordered one and hope it will work. In the meantime I use my remote control GUI. I have anyway a laptop connected to make astrophotography.

 

Regards,

Ronald

[OzAndrewJ]

Gday Ronald

Unfortunately my AutoSTAR is the old design with the 24 pin display.

Ahh OK, when you mentioned 11 of 14, i assumed a 14 wire ribbon.

 

As far as I know the display has a Seiko Epson SED1233DGB controller which is compatible to the S1D12303.

OK, The notes i have showed the original listed alternative someone found was

an Optrex DMC-50747NF-AK and that uses the S1D12303 control codes

so all that matches. Based on code review for "special" characters used

the ROM chipset nomenclature would have been S1D123**D16**

 

Andrew Johansen Melbourne Australia