Which WRT54G Power Supply?

Steve Wertz hath wroth:

I think (not sure) that Linksys started shipping the smaller (and more efficient) switching power supplies with the WRT54G v6. Either adapter will work, but the smaller switcher is far more efficient. Just put your hand on the power supply when running and notice the difference in how hot it gets. However, ethics require that you return the unit you bought with whatever was originally supplied. Swapping power supplies is not returning products in their original sellable condition.

I seem to recall that when I had a switcher on my Dell laptop that there was some interference on the local TV, while changing back to a traditional xformer caused no TV interference...

OK. I thought maybe they just down-sized due to copper prices and this new one would be less reliable.

Ethics would also dictate that Linksys should exchange a defective product (known issue with that model) that was bought

1.5 years ago, but only unwrapped and taken out of the box and used 2 weeks ago. Granted, they probably can't tell how long it's been in actual use.

Thanks for the PS info, Jeff.

-sw

Steve Wertz hath wroth:

Nope. Just efficiency. The cell phone crowd has gone to switchers for at least 7 years. One nice feature is that they turn totally off when there's no load. They also turn off when overloaded or shorted. The rising cost of copper is a fairly recent phenomenon.

I've had more failures on the xformer variety than the switchers. The problem with the xformer types is that they get hot, especially if overloaded. They're required to have a thermal fuse inside. Get it hot enough, and the fuse blows, permanently. In general, the hotter it gets, the faster if fails.

What known issue? Punch and hold reset for over 30 seconds. Upload latest firmware. Try again.

"P.Schuman" hath wroth:

Yep. Your unspecified model Dell laptop power supply probably is running at 60 watts. If it were 95% efficient, it would still belch 3 watts of heat and RF (mostly heat). Meanwhile, the Linksys switcher runs at perhaps 6 watts. At 95% efficiency, that's only 0.3 watts of heat and RF or 10 times less. It's also more difficult to reduce RFI from bigger power supplies. The Linksys power supply might make some noise, but it will probably be 1/10th of the Dell power supply.

I do some ham radio at home. Listening on the various HF bands (3-30MHz), I can hear LOTS of RFI junk from various electronics around the house. Wall warts were a major problem until I butchered a power strip by adding ferrite beads on the power wires, and bypass capacitors. Most of the RFI from the wall warts was from conducted radiation. (Conductors radiate. Components do not). Within reach, I see 5 different switcher type wall warts, with no associated RFI. Incidentally, the worst RF noise makers in my house are the La Cross WS-9520-U weather station, DirecTV DVR, and various computers around the house. However, the ultimate RF noise maker is my neighbors giant plasma TV.

This was overheating (or something) under heavy load. It would last 36-48 hours at a time, then die. All the LED's made it look like it was still working, but the router was in outer space somewhere. So I threw a copper heat-sink on the Broadcom chip and that extended it's MTBF to 5-6 days at a time, but it still croaked regularly. It was not over-clocked or anything. Several sites mention that this runs too hot, overclocked or not.

It wasn't the PS, either. Unplugging it at the back of the unit for 5 minutes, it would last another 30 minutes. Unplug it for 4 hours, it would last another couple days. Latest firmware was installed after the first failure - same symptoms.

-sw