Conclusion to the Conext CNB750 UPS thread

[andrew77]

For all of those that might have been waiting for me to tell them what happened with this UPS (and probably forgot by now) here is what I've done:

I received the parts I needed to replace the ones I took off of this UPS to use on the other UPS. I got some diodes that were the wrong package. I got all these MOSFET's: FQB33N10L, FDP61N20, and HRF3205. The HRF3205's were not used since none of those MOSFET's were bad.

I removed the d2pak MOSFET's, cleaned up the pads, and then put the new ones on. I cleaned the pads for Q35 and D8. Soldered these parts on, it was a little tricky to make the diode that I got work because it was SOT-416 and should have been SOT-23.

I removed the heatsinks for the high voltage side of the inverter, removed the MOSFET's, used desoldering braid on the holes, soldered one heatsink back in place, put some heatsink compound on the MOSFET's, and soldered the one set of MOSFET's back in place. I soldered the last heatsink in place and soldered the last set of MOSFET's in. Sorry all I have is a picture of the heatsinks off and MOSFET's off.

After doing all of this I was rewarded with this UPS coming back to life! Apparently all that was wrong with it before I pulled parts off it to repair the other UPS was two of the MOSFET's in the high voltage section were shorted. Couldn't have done this without the help of this forum. Thanks everyone!


Andrew

[starfury1]

Re: Conclusion to the Conext CNB750 UPS thread

So you now got both working OK....Good one

Yes thanks for the feedback thats useful info for someone ill bet, further down the line

Cheers

[Fizzycapola]

Re: Conclusion to the Conext CNB750 UPS thread

Very thoughtful to leave a conclusion with photographs.