Death of my paralleled LM4780

[RDV]

Wow, thats a lot of good advice. I think it would be nice to summarize some of that and throw it in the wiki.

It is done. It's added to the LM4780 Paralleled article.

[RDV]

I dragged the PCB out of the trash and had a good look at it and I believe I may have shorted a couple of pins(there's 27 of them) partially so I carefully pryed up all the long side pins a bit and cleaned all the flux away and checked for continuity from the supply rails to the proper pins. I think I just jumped the gun when I tested the board by not cleaning up the board and stuff. I'm gonna test it again soon after I install some connectors so I don't have to do all that unsoldering and resoldering. I may also replace the bypass caps on the negative rails as they may have been damaged when the chip smoked.

It seems I'll never learn to be more patient. The thing may still not work, but there's a lot better chance that it will now.

RDV

[joecool85]

Well, good luck.

[RDV]

One of the 27 pins(#16) on the LM4780 was not soldered well which caused my rebuild not to work. I troubleshot for about 4 hours or better before I got it. 27 pins is a bunch of pins to be soldering. It's working wonderfully as a guitar amp at the moment replacing my blown LM3886. I've got another parallel LM4780 PCB to build and make a stereo LM4780 amp with a 20v + 20v 400VA tranny. I picked the lower voltage to make the amps run cooler (at the sacrifice of a bit of wattage). They'll still be a good 80 clean watts per channel, and I won't have to use as big of a heatsink methinks. It'll still be pretty good size.

RDV