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[photo444]

Hi All,
I have been using an AstroEQ V4 DIY board for number of years flawlessly, but recently it stopped working. The 'Status' LED did not fast-blink anymore: When it was connected to PC (running CDC) the 'Status' LED is OFF, and when I tried to connect to EQMOD using the EQMOD_toolbox the 'Status' LED is slowly blinking as "EQMOD is not responding". And the 'Link' LED is blinking alright.
The board, however, can be flashed without any problems (even with the up-to-date V8.18). 
Thank you for your help.
Paul

[TCWORLD]

Hi Paul,

What version is the PCB for the board you are using?

If it is an older version (< V4.4 I think it was), then please refer to this post:

https://www.astroeq.co.uk/forum/index.php/topic,386.msg2356.html#msg2356

You will need to either add a single 1k resistor between two pins on the PCB in order to to use the newer firmware versions.

Kind Regards,
Tom

[photo444]

Hi Tom,

It is great to hear from you at lighting speed. The board is V4.4-PTH. When I was scanning the discussion you have quoted, I thought it was not my case. I will add the resister and report here.

With many thanks,
Paul

[photo444]

Hi Tom,

To make sure, please check the picture if pins are correct.

Thanks,
Paul

[photo444]

Hi Tom,

After adding the resistor the controller showed the same malfunction as before. It accepted the configuration nicely, I ran CDC, connected to EQMOD, the EQMOD hand controller showed up nicely as the scope is parked, RA was ticking as usual. I selected a star to slew, it stuck again with the status LED slowly blinking, RA and DEC unchanged. And the Task Manager said that the EQMOD is not responding. I am sorry to report this.

Thanks,
Paul

Edit: A thought came to me when I was reading the recommended article, the controller is in the ST4 mode so it is looking for ST4 signal?  Is there a way to disable the ST4 stand alone mode? Just a thought.

[TCWORLD]

Could you save the config settings you are using and attach them to a post here?

Also, what version of EQMOD are you using?

[photo444]

Hi Tom,

I am using EQMOD v2.0. V1.9 and 1.8 gave the same results.

Thanks for fast response.
Paul

[TCWORLD]

Hi Paul,

Sorry for the delayed response.

Not really sure what is happeneing. With the resistor in place as pictured, it shouldn't enter the standalone mode. Not sure why it is.
Do you have a multimeter? If so, could you double check the resistor connections - you should be able to measure 1k between pins 2 and 4 of the GPIO connector (one pin in from each end). Could you also check output of the 5V regulator, make sure that it is at 5V.

Did anything else change between when it was working and now?

[photo444]

Hi Tom,

I have checked those you have suggested.
1. The resistor read through pins 2 and 4 of GPIO 1.0 k ohm. OK
2. The voltage appeared at input and output of the regulator: 12.3V (Input) and 11.7 (Output, too high) Your guess is right. I also found the transistor at the corner near the power input jack is very hot.
I also quickly made the HC, tried to move the mount using it, and no vail. This may be understandable due to the malfunction 2. above.  It seems a hardware problem rather than software.

I would await for your leading what to do next.

Thank you for your help.
Paul

Edit: I was mistaken the Schottky diode as a regulator. Measuring again showed input:11.7V, output:4.23V. The report of 2 above is wrong.  After a while, 4.23V became 3.96V, and the regulator is hot.

[TCWORLD]

4V is quite low and could be causing brownout issues.

Could you try unplugging the two motor driver boards and see if that affects the 5V rail (I have seen one driver board fail and short out the 5V rail before).

Failing that, it's possible either the MCU has been damaged, or one of the electrolytic capacitors has gone bad.

[photo444]

Yes, the 5V rail went back to 5V after removing DRV8825s. I tested with several DRV8825s, status of the drivers was identified/screened with the voltage at the EN pin.  V(EN)=5V is good, and <3V appeared 'BAD'.  Now I placed good drivers, and hope the controller will keep me busy with AP.

I will keep my eyes on the 100 microfarad electrolytic capacitor.

Thank you so much for the experienced and valid suggestions that helped me to fix it.

Sincerely,
Paul