I brought my Re:load Pro to a worksite to diagnose a customer installation. Apparently the installation was failing because the 12V system was wired backwards. If discovered the installation error when connecting my Re:load Pro. It made a "pop" and the familiar (expensive) solid-state burning smell. Consulting gig successful! Customer installation fixed! But I came home with a fried Re:load Pro. I figure the reverse polarity shorted through Q3's body diode and fried sense resistor R16 and possibly Q3.
- Reverse polarity 12V across red and black banana jacks
- made "pop" sound and solid-state smell
- R16 (current sense resistor) is smoked
- No visible damage to Q3
- LCD screen no longer displays anything. This is what worries me the most.
Can this be repaired by replacing R16 or possibly Q3 (power transistor), or did the reverse polarity propagate into the ADC and blow up the the microcontroller as well?
Sorry about that! Your diagnosis seems correct. We're actually diagnosing another reverse-polarity damaged unit right now to see what might be damaged besides R16; hang tight and we'll get back to you.
I did the same exact thing with my unit, and I would definitely need to know what to replace, as well!
Can we put a diode in series with the banana jack to avoid the issue in the future?
Yes, definitely. I didn't design that in because it reduces the Re:load Pro's ability to handle very low voltages. I'm looking at adding a slow-blow fuse in future hardware revisions, but first I need to evaluate exactly what was damaged by the event.
Should I open up a support ticket, or should I wait to hear back from you here?
If it's okay, give me a few more days to figure out exactly what's damaged and what the best resolution is.
One could argue that perhaps it would be reasonable to alter the following sentence in the Re:Load Pro's description a bit:
Virtually indestructable. As long as you don’t exceed 40V, there’s not much you can do to damage this. ESD, overcurrent, overtemperature and reverse polarity are all protected against.
I really need to get this unit back up and running. Do you have a fix, of should I send it in for repair/replacement?
I'm sorry for the delay. We're actually out of stock at the moment, so all I can offer is a refund until we have more new (or repaired) units to send you. Ping me an email at firstname.lastname@example.org and we can sort something out.
I'm sorry. I fell out of the loop for awhile. Do you have any of the main boards available? I can swap them out. I'll buy a new board if necessary.