My friend recently asked my help with his 10 year old 26 foot trailer that sits permanently on a site in Pennsylvania about 105 miles from my house. The complaint is that while all 110 V functions work fine, very few 12 volt functions work. He recently installed two new group 27 batteries on the tongue. He did not have a test light with him, so I had him pull each fuse one at a time for visual inspection. He said all looked good.I packed up my electrical tools and drove out today to help him figure this out, because he was unable to power in the slides as part of winter preparations. The first thing I noticed was that only three out of the nine fuse ports had power on the input side ( the ones under the green line). The other six ports under my red line did not have power.I temporarily moved some of the output wires from the dead circuits to the right side and each feature then worked properly and we closed the slides. I imagine there is some sort of bus bar running on the backside of this panel from the main red positive post feeding the top of each fuse terminal that may have broken between the third and fourth position. Any thoughts before I proceeded?

Remove the board and check the back side.

Some older converters had two outputs from the converter, one filtered and one unfiltered. My guess is that the filtered side has failed. Possible capacitor.

enblethen wrote:Some older converters had two outputs from the converter, one filtered and one unfiltered. My guess is that the filtered side has failed. Possible capacitor.My thoughts as well.

I think its progresive has replacement converters for these old units and at a fair price ..

The right hand three are filtered and tied to the battery, the others are switched by relay to the converter output.That converter is so obsolete, better off to replace it- dirty power, 3 amp poor battery charger, etc.But, if you want to try to repair it look at http://parallaxpower.com/archived-tech-docs/# for schematics and service manual.

Magnetek 3230 power converter problem | Good Sam Community

BFL13
Explorer II
Nov 09, 2019
" The first thing I noticed was that only three out of the nine fuse ports had power on the input side ( the ones under the green line). The other six ports under my red line did not have power."

There are two positive wires from the converter, red and blue. One for the 6 and one for the 3. The 3 use the battery to filter those circuits, and those three had power.

All 9 should have battery power if the converter is not on. Trouble shooting should reveal how that can be.

If you replace the converter with a newer type and want to use that same circuit board, you must "jumper" the red and blue connections so the one blue wire from the new converter can power all 9 circuits.

Newer converters have "clean power" so they don't need the battery to act as a filter.

The 6300 circuit board does not have those two 30a RP fuses like the 7300 board does. I don't know how RP is handled. I replaced my 6300 with a deck mount converter that has its own RP fuses, and kept the 6300 circuit board with jumper.
cavie
Explorer
Nov 09, 2019
The photo looks like the product of a loose connection. The converters have 2 "Reverse polarity" fuses to pervert damage by improper battery installation.
All_I_could_aff
Explorer
Nov 09, 2019
Thanks guys, it was 19° yesterday when I was messing with this thing, perhaps that’s part of the reason I didn’t notice the burnt wire while laying on the cold floor. I was happy to get the slide retracted for my friend. Come spring we will go out there again and resolve it properly. Thanks again to everyone for your tips
Bobbo
Explorer II
Nov 09, 2019
Agree with the PD 4600 model replacement. That also comes with a replacement 12v circuit board. Just cut back the burned negative wire to new copper and put in the new circuit board.
All_I_could_aff
Explorer
Nov 09, 2019
Thanks everyone. The filtered and unfiltered power makes sense, but I now have some new information that may help... looking at some of my pictures taken on a different angle, I now see that the main battery negative lead area is corroded and burnt. I guess the bundle of white wires had been blocking my view. I have a feeling my friend may have briefly reversed polarity when he installed his new batteries recently. I now regret that I didn’t check actual voltage, as opposed to simply presence of nominal 12V at the battery and fuses. I can hear it humming faintly when the circuit breaker is on, but I’ll bet the converter is fried.
wa8yxm
Explorer III
Nov 09, 2019
I too am guessing that's one of those "Older converters" That someoen mentioned with both filtered battery connected output (The ones on the right) and raw rectified AC (I would never call it DC) on the rest.

FOr this type of converter there is a relay that connects the two when not on shore power..... NOW.... If nothing 12 v is working on shore power odds are the converter portion is toast.

Suggested is a Progressive DYnamics 4600 (Smallest 4600 they make) and replace the "Guts" the thing (the electronics BEHIND the fuse/breaker panel)
That is assuming the guts are behind the breaker panel

If the converter is in a box by itself. Progressive Dynamics 9200 series (Again the smallest 9200)

Randy at Best Converters is your friend.
Chris_Bryant
Explorer II
Nov 09, 2019
The right hand three are filtered and tied to the battery, the others are switched by relay to the converter output.

That converter is so obsolete, better off to replace it- dirty power, 3 amp poor battery charger, etc.

But, if you want to try to repair it look at http://parallaxpower.com/archived-tech-docs/# for schematics and service manual.
midnightsadie
Explorer II
Nov 09, 2019
I think its progresive has replacement converters for these old units and at a fair price ..
Nv_Guy
Explorer III
Nov 09, 2019
enblethen wrote:
Some older converters had two outputs from the converter, one filtered and one unfiltered. My guess is that the filtered side has failed. Possible capacitor.

My thoughts as well.
enblethen
Nomad
Nov 09, 2019
Some older converters had two outputs from the converter, one filtered and one unfiltered. My guess is that the filtered side has failed. Possible capacitor.