A Forum run by Enthusiasts of MidNite Solar

Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: Hockey on June 18, 2024, 12:14:36 AM

Title: 'dead' Classic 250
Post by: Hockey on June 18, 2024, 12:14:36 AM
A Classic 250 ended up in my possession, given to me by a friend who said it was good only for parts.

Symptoms:
Powers up when connected to a 24V battery, but shows 12.6V for about 2 seconds, then 0V.
After a VMM, it defaults to 12V.  Following selection of correct voltage (24V), date, etc, it freezes on "SENDING DATA"  "4136  502"
It never progresses past this, and remains frozen.  Buttons are unresponsive.
After powering off and on, the MNGP keeps booting up as if VMM buttons were pressed, so cannot get further along past the "SENDING DATA" freeze.

I connected the MNGP to a different Classic to get it past the VMM initialization process.  Everything works fine on the other Classic, so I suspect the MNGP is fine and the issue is with the control board.  I reconnect the MNGP to the original Classic, it shows 0V Battery voltage.  I connected 50V to the PV, and nothing registered on the MNPG.  Buttons are responsive.

Any thoughts?






S
Title: Re: 'dead' Classic 250
Post by: ClassicCrazy on June 18, 2024, 09:18:33 AM
I have seen that mngp sending data problem .
That happened both times during firmware updates .
That last time I think I wasn't giving enough time for power down before trying to set it up.
The first time I did a hard reset with jumpers instead of vmm button pushing and that seemed to fix it.
I am wondering if there is a mismatch between Classic firmware and MNGP firmware .
What I would do is load up the newest firmware in both Classic and MNGP and then see if they work. Do at least the VMM after firmware update , but don't do like me and give it a minute or two after powering back on after update before you go right to the VMM !
Hopefully that will fix your problems.
Larry
Title: Re: 'dead' Classic 250
Post by: Hockey on June 18, 2024, 11:06:18 AM
Figured it out.

There was another thread here that indicated the MNGP would work if plugged into any of the RJ12 jacks on the control board.   With the MNGP connected to the "Slave/Out", it works properly.  See attached photos.   So it seems the  RJ12 jack labelled "Remote" is the culprit here.

Larry, As you suggested, I will update the firmware for both MNGP and Classic to see if that 'fixes' the Remote jack, but I suspect this is a hardware issue.

Assuming hardware, not sure it's worth diagnosing/fixing...  I.E. what functionality is lost without a functional "Remote" jack?   I believe 2 MNGP LEDs won't light up, and I may not be able to use Follow Me with this unit?  Anything else to be aware of?

Wondering if there is a deeper fault in the control board that may propagate and cause other issues.



Title: Re: 'dead' Classic 250
Post by: ClassicCrazy on June 18, 2024, 11:41:55 AM
well that is an easy fix ! Not sure one that top jack , maybe bad solder joint on the connector ?
Other than the LED lights should work okay.
You may be  still able use Follow Me with just one jack - just don't use the return line .
See this
https://www.midniteftp.com/support/kb/faq.php?id=112
Larry
Title: Re: 'dead' Classic 250
Post by: boB on June 18, 2024, 10:53:11 PM
Nice !

I think that with only one modbus phone jack, you can't do follow me fully is the only drawback I can think of.    The end unit can't tell the front unit what it knows.


Title: Re: 'dead' Classic 250
Post by: Wizbandit on June 19, 2024, 02:50:12 PM
FYI - Classic and MNGP firmwares are "matched".  Swapping MNGPs between units with different FW will cause what you see on SENDING DATA...
Title: Re: 'dead' Classic 250
Post by: Hockey on June 19, 2024, 07:59:58 PM
Firmware at the moment:
MNGP 1933  01/08/2015
CLASSIC 1923 12/18/2014

Will update both and report back.
Title: Re: 'dead' Classic 250
Post by: Hockey on June 19, 2024, 08:55:47 PM
I updated the Classic firmware to 2193.

When attempting to update the MNGP firmware, it kept failing...   Perhaps MNGP firmware updates only succeed when connected to the top 'Remote' jack...?  At this point I have mismatched firmwares.

So,

I connected the MNGP to another Classic - a surrogate with a functional Remote Jack - and the MNGP 2186 firmware update was successful.

As I expected, firmware update did not 'fix' the  Remote port.

9V and Gnd pins are fine on the Remote jack.  It makes sense since the MNGP has power.  So Rx and/or Tx are the culprit.  Pins inside the jack look okay, and there is continuity to underside of the control pcb. Now I am looking at that ST232 IC (U14) with suspicion.  Bot not going to burn any more time on this!  It's not a game changer.   Just have to remember the surrogate trick next time firmware needs updating.