A "nice" YoungYear unit?

[Pentium4]

Re: A "nice" YoungYear unit?

Cool project! Thanks for sharing. I always liked how YoungYear use a good sized main transformer and large input caps. I've seen them use ERL-40 and even ERL-42 in some Ultra units if I remember correctly. I never liked the heatsinks they used though. Very thick but not a lot of small fins to help dissipate heat, especially with a slow spinning fan. I bet that is contributing to the heat some!

The 3.3V rail shouldn't increase or decrease too much - it is independently regulated with a mag-amp circuit from the 5V rail.

Maybe I'm just rusty here, but how is the 3.3V independently regulated here? It looks like there is only one output toroid and it looks jumpered where the 3.3V mag-amp coils should be. Wouldn't that explain the high voltage since the load would be lowest on this rail?

[momaka]

Re: A "nice" YoungYear unit?

Maybe I'm just rusty here, but how is the 3.3V independently regulated here? It looks like there is only one output toroid and it looks jumpered where the 3.3V mag-amp coils should be. Wouldn't that explain the high voltage since the load would be lowest on this rail?

No, you are 100% correct here.
Seems I have overlooked the pictures posted in this thread and assumed the unit was very similar to my two YoungYear PSUs, both of which have mag-amp -regulated 3.3V rails.

If there is no MOSFET to regulate the 3.3V rail voltage down from the 5V rail, then this would indeed explain the 3.3V rail being so high. But why would YY do this in such a high power PSU (well, relatively speaking) is beyond explanation then.

Either way, also great to see the O/P come back and report that the PSU is still running well. Goes to show that even old units can be used with new systems just fine. A lot of modern reviews go into too many details about voltage spikes and overload test now, yet neglect to mention the importance of good electrolytic caps, both for the APFC and the output.

[bauto601]

Re: A "nice" YoungYear unit?

No, you are 100% correct here.
Seems I have overlooked the pictures posted in this thread and assumed the unit was very similar to my two YoungYear PSUs, both of which have mag-amp -regulated 3.3V rails.

If there is no MOSFET to regulate the 3.3V rail voltage down from the 5V rail, then this would indeed explain the 3.3V rail being so high. But why would YY do this in such a high power PSU (well, relatively speaking) is beyond explanation then.

Either way, also great to see the O/P come back and report that the PSU is still running well. Goes to show that even old units can be used with new systems just fine. A lot of modern reviews go into too many details about voltage spikes and overload test now, yet neglect to mention the importance of good electrolytic caps, both for the APFC and the output.

The system seems to do fine with the somewhat high 3.3v rail voltage, so it's no biggie that it's part of the group regulation and can't be modded. I really think that the Panasonic output caps and the upgraded 12V rectifier are holding it together when it's running this hot. During some BeamNG drive today, the case temp reached 50 degrees celcius at the inlet of the psu. I've got a temperature probe located around that region, it's right above the GPU cooler.

One thing i've forgot to mention is the 50Hz hum this PSU got. It's noticeable when the pc is idle, but during a heavy load the hum really becomes as loud or even a tad louder than the fan noise. Even more so when the PSU is heated up. Always had this weird hum, didn't get worse either. It's actually kinda funny to hear the hum go when the PC is loading a game or something like that. And weirdly enough the brain starts to remember the different kind of 50hz humming patterns when starting programs. I know exactly when the desktop is about to pop up when booting up windows, or when the BeamNG loading screen is about to end while loading a map

[momaka]

Re: A "nice" YoungYear unit?

50/60 Hz line hum from an ATX PSU is never a good thing. Check both primary caps for proper capacitance and ESR. One or both might be bad. If that's the case, that's where you'll be seeing the line hum from. If they are OK, though, then it might be one of the common-mode chokes on the input... though I personally have never seen one go bad and make a hum.

Yeah, I know what you mean about the PC making specific noises and remembering them. I have a PIII Dell laptop like that - has a ton of coil / CPU VRM audible switching noise. I can easily tell when Windows is loading, when a USB stick is inserted and if it's being read or written to, or when my browser (New Moon) is stuck on a script on a web page and likely won't get unstuck anytime soon.

[bauto601]

Re: A "nice" YoungYear unit?

50/60 Hz line hum from an ATX PSU is never a good thing. Check both primary caps for proper capacitance and ESR. One or both might be bad. If that's the case, that's where you'll be seeing the line hum from. If they are OK, though, then it might be one of the common-mode chokes on the input... though I personally have never seen one go bad and make a hum.

Yeah, I know what you mean about the PC making specific noises and remembering them. I have a PIII Dell laptop like that - has a ton of coil / CPU VRM audible switching noise. I can easily tell when Windows is loading, when a USB stick is inserted and if it's being read or written to, or when my browser (New Moon) is stuck on a script on a web page and likely won't get unstuck anytime soon.

If one of the primary caps was already bad a few years ago it's lasting for quite some time now despite of that. Once a cap starts to degrade it goes quite fast right? Could it be the passive PFC choke instead that's making these noises?