http://i-t-w.com/parts/lulzbot-taz-45-power-supply
That’s the PSU for the newer 4/5 printers. The spec on Lulzbot says it’s a 500W, so it should work fine. You might have to adapt wiring though.
whats wroung with the orginal power box that you can buy for the taz 3? And im not 100% sure its the power box causing the problem.
If the post adding up your power use is correct, you are above what the supply is rated for. They can sometimes provide more current than the nameplate rating, but not always. And they tend to get inefficient when they are outside their spec. You mentioned it only happens with the bed heater on, which also indicates a power problem. I suppose the supply could be alright, but the bed heater shorting… What’s the resistance of the heater? Maybe someone here will measure theirs and you can compare. I’d offer, but my Mini will have a significantly different power budget.
If the other post is correct and you are drawing 400W from a 360W supply, I’m surprised it doesn’t shut itself down. Many SMPS designs include over-current protection.
Well it really only supplies 360 watts, which causes slower heating of the bed, and extruder. But after a while it starts - shall we say leaking - noise back onto the main lines coming into it as internal junctions degrade from the stress.
I want one of the current generation Taz 5 production power supplies. Anyone have one of those they want to sell me heh.
HEE! HEE! Yes, they are nice. My printer sure works better now with that 500 watt supply. Maybe IT Works will have some again soon. 
Argh! don’t tell me that, now I really want one!
Maybe, for heated beds, we could get away with just chopping line voltage down to 24V equivalent pulse-width, then run that power through a solid-state relay controlled by the electronics normally. 
Seriously though, if there is significant interest, I’ll design, build, and sell a few samples, probably really cheap. Probably need something like that for TazMega anyway.
I went ahead and ordered a 24v 400w power supply from ultibots with 17 amps, would this work for the taz 3?
http://www.ultibots.com/24v-400w-power-supply-s-400-24/
I have one of those, brand new and rated 500W, that came with my TAZ 5. It doesn’t solve the problem.
Tried powering through a UPS, that failed too (the low frequency power surges were killing the UPS and the lights still flickered).
Tried adding 20,000 uF bulk capacitance to the 24V DC power line, no effect.
Any incandescent or florescent bulbs on the circuit flicker when the TAZ 5 heated bed is on. Like the occasional reports of PWM fan noise, the PWM bed heater power surge effects appear to be normal for the TAZ 5.
well that solved my problem, the new power box worked but now want to take extra precautions of not burning my house down. Anyone know what I can run through so in case something bad happens it will shut down.
I wonder if an isolation transformer would help? (or is there already a transformer in the power supply?)