Midnite Classic 250 switches between mppt bulk and resting

[Thai]

Hi boB,

It started to rain today (for the next few days) so I was not yet able to check out the board. But based on the image you sent for the R145, how do I measure? Where do I place the leads? Sorry for such a basic question, but I haven't done this on a circuit board before.

Thanks,
Thai

[ClassicCrazy]

Hi boB,

It started to rain today (for the next few days) so I was not yet able to check out the board. But based on the image you sent for the R145, how do I measure? Where do I place the leads? Sorry for such a basic question, but I haven't done this on a circuit board before.

Thanks,
Thai

Put your meter in ohms mode - if it has ranges and not auto ranging meter put it on lower ohms scale. Touch your leads together first to make sure your meter is working and you are on ohms - you should see some number close to zero. Then  just measure the resistor with a meter lead on each side of the resistor .

Larry

[Vic]

Hi boB,

It started to rain today (for the next few days) so I was not yet able to check out the board. But based on the image you sent for the R145, how do I measure? Where do I place the leads? Sorry for such a basic question, but I haven't done this on a circuit board before.

Thanks,
Thai

AND,   in addition to Larry' guidance,   the silvery ends of that resistor are its connection points.   Place either lead of the DMM one one end of the resistor,   and,   the other lead on the other end  (there should be very little difference in the resistance readings if the leads are reversed),   and wait for the reading to stabilize.   Those two thru-holes,  one at each end of the resistor may well be its connection to the PCB.   But,   if possible place the DMM probe tips on the silvery ends of the resistor.

IMO,  Vic

[Vic]

Thai's problem has nothing to do with bad PV connections.   A bad PV connection will not cause the input voltage NOT to drop when the controller sweeps.

I will put a picture of the PCB of the resistor to measure, Thai.  Give me just a few minutes.

YES,   Thanks boB,   would normally say,  "what was I thinkin',   but obviously,  NO thinking was involved in that Post,   sorry for any distraction in that poorly-reasoned statement.

Vic

[boB]

Thai's problem has nothing to do with bad PV connections.   A bad PV connection will not cause the input voltage NOT to drop when the controller sweeps.

I will put a picture of the PCB of the resistor to measure, Thai.  Give me just a few minutes.

YES,   Thanks boB,   would normally say,  "what was I thinkin',   but obviously,  NO thinking was involved in that Post,   sorry for any distraction in that poorly-reasoned statement.

Vic

That's OK, Vic.  Happens to me ALL the time !

😁😁😁😀😀😎😅😑

[Thai]

Hi boB,

Thank you very much for your time and your help, but I am obviously over my head. It has been raining here (my SCC is mounted inside a cabinet outside on a trailer) and in a hurry, I attempted to measure the resistance and carelessly did NOT check to be sure that the SCC was shut off first. Consequently I fried it  :-( and now it won't even turn on. My bad.

Anyway, many thanks for all your guidance and patience. I will contact tech support on Monday to see if I can ship it back for repair. Otherwise, live and learn ...

Have a great weekend!
Thai

[boB]

OK, Thai.

That's OK.  You tried.  But as we always say, we do not make progress on electronics unless we have let the smoke out a few times.

So, you done good !  It's only a charge controller after all...  And it's raining anyway so no power lost today.