Nexstar+ Corrupted

[Jojo204]

Hey all,

Unfortunately today after some time I was about to go out to do some observing however it seems my Nexstar+ Handset has gone poof. I resetted it holding the celestron logo button while turning on to no avail. I decided to firmware flash it. I plugged it into my PC, and on screen it displayed "BOOT LOADER Serial Invalid Pkg: 0002". The number has varied between 0002, 0088 and 00AA. I then got it to the stage where it said User Keypad Entry underneath BOOT LOADER Serial. However when the software started updating the handset the message on screen changed to BOOT LOADER Serial, PASS THROUGH OFF. And the "off" would switch to "19.2K" then back to off repeatedly. I think 19.2K was something to do with the file size. After a while of the software being stuck on the first package at 3%, it said memory corrupted and cancelled the update. 

Is there anyway to restore this? Or do I have to look into buying a new handset? Regards.

[DaveL59]

can't help regarding the reset/recovery, but the 19k2 likely refers to the serial baud rate. I don't know if its possible to try a lower speed such as 9k6 that might be more reliable tho slower.

[Jojo204]

10 minutes ago, DaveL59 said:

can't help regarding the reset/recovery, but the 19k2 likely refers to the serial baud rate. I don't know if its possible to try a lower speed such as 9k6 that might be more reliable tho slower.

Ah, that makes sense. Not sure if its possible to lower tbh.

[DaveL59]

hopefully someone will be along that can help further as I've never attempted a re-flash on my SW Synscan, don't have the right cable and so far not felt the need 🙂 

[malc-c]

20 hours ago, Jojo204 said:

Hey all,

Unfortunately today after some time I was about to go out to do some observing however it seems my Nexstar+ Handset has gone poof. I resetted it holding the celestron logo button while turning on to no avail. I decided to firmware flash it. I plugged it into my PC, and on screen it displayed "BOOT LOADER Serial Invalid Pkg: 0002". The number has varied between 0002, 0088 and 00AA. I then got it to the stage where it said User Keypad Entry underneath BOOT LOADER Serial. However when the software started updating the handset the message on screen changed to BOOT LOADER Serial, PASS THROUGH OFF. And the "off" would switch to "19.2K" then back to off repeatedly. I think 19.2K was something to do with the file size. After a while of the software being stuck on the first package at 3%, it said memory corrupted and cancelled the update. 

Is there anyway to restore this? Or do I have to look into buying a new handset? Regards.

The bootloader is a small section of code that typically is placed at the top of the memory at the time the microcontroller is programmed.  This little bit of code is what the handset talks to when flashing the new firmware (the firmware is the main code that handles the instructions from the handset and converts them into movement of the mount).  If the bootloader is corrupted then the only way to resolve that is to reprogram the microcontroller, either with a fresh copy of the bootloader, or with a full image that includes the firmware.  I've repaired several Skywatcher motor control boards by reprogramming the PIC Micros on them with the Skywatcher firmware, but I've never tried flashing the firmware of a handset before.

The process for flashing the handset firmware can be found here Firmware update  - It states a different combination to the buttons you used... maybe this is the issue? - You could try that, and if you are using a USB to serial adaptor or an old PC with a COM port, set it to 19200 baud in the properties via device manager.  Hopefully the image file the application loads also has a new bootloader, or you have somehow placed the handset in some form of limbo mode and the bootlaoder is still intact 

[Shimrod]

21 hours ago, Jojo204 said:

Ah, that makes sense. Not sure if its possible to lower tbh.

It's worth checking you have the latest version of CFM -  the celestron firmware manager - you can get that here:  CFM. You mention a Nexstar+ so this should be the software you are using to update rather than the original Nextar firmware update linked in malc-c's post.

I am unclear how you have the handset connected to the PC - did you also have it connected into the mount and the mount turned on? Does your handset have a serial or USB connector?