I haven't ever heard that using not compatible socket A CPU would break the MB and how that would be possible. Did the system work at some point or did you just build it?

But, your PSU is definitely a problem as it has only 18A for 5V line according to what I googled, which is far too little for these systems. Your board doesn't have 12V VRM, so system is very 5V heavy and your new PSU is designed for 12V loads. Your PSU can be also group regulated and when you load 5V heavily, the 5V rail simply drops too low. All this would cause boot issues and maybe your PSU over current protection kicks in as it can't deliver the required amps to your 5V rail and those can be quite high especially when the system is powered on and every component with CPU kicks in at the same time.

There is also another potential problem with the motherboard itself: VRM caps are bad and this is more than a common issue with these early 2000s board as many low-esr caps made during those years were of subpar quality to begin with and in many cases failed within couple of years.

Thank you, I was not aware of that 5V line limitations of the PSU. I have the possibility to get a Asus A7N8X-X mainboard for just 30 Euros: would this
work with the PSU? (Note from theretroweb: "This board can be modified to use 12V for the VRM")

Thanks!

PS: It was working with the old PSU, but it died.

I haven't modded VRM on these boards personally, so if you think you can do it, then why not. Needs some soldering without a doubt, but I don't think it should be that difficult. Another option is to get a Socket A board which already has 12V VRM for CPU. If there is P4 connector on the MB, it should use the 12V provided from that connector for CPU, unless it is some completely moronic design.

Another option is to get PSU which can deliver enough amps on the 5V line. I personally wouldn't look anything below 25A in this case, preferably close or at 30A.

Edit: if you are going to use another PSU and decide to go with vintage one, I'd recap the secondary from those ~20 year old PSUs so you don't end up with a dead PSU or system. By the way, when you said that your previous PSU died, it may have killed your board too. Old quality PSUs should go out out gracefully because of protections, but cheap trash can definitely kill parts when they give up.

Thx CharlieFoxtrot. Maybe this mod is already enough Re: Socket A Motherboards That Have 12V-Centric VRMs??

Even if LC-Power PSU is brand new it's LC-GARBAGE. Try with some better PSU.

So... did the Athlon 1900+ work OK with the new supply or did you change the psu when you tried the Barton ?
And yes you could fry something using an under rated PSU with an over power cpu (on board Vregs would be fighting to keep volts proper and possibly short out... just one scenario)

Horun wrote on 2023-10-22, 02:12:

So... did the Athlon 1900+ work OK with the new supply or did you change the psu when you tried the Barton ?
And yes you could fry something using an under rated PSU with an over power cpu (on board Vregs would be fighting to keep volts proper and possibly short out... just one scenario)

The old PSU died when I tried to run the board with the Barton CPU, but I think this was just by chance. But what I don't understand is the new LC-Power PSU
provide 27 Amps on the 5V line what should be enough?!

I think the motherboard just died together with the old PSU.

A new Asus A7N8X-X is already on the way 😉

EDIT: The 27 Amps were a wrong description on the shopping page, it is 18A 🙁

Which PSU should I use? Is 25A on the 5V line enough? Otherwise the options are quite expensive:

e.g. Corsair HX Series Platinum HX1200 ~300€ (30A/5V)

Maybe someone can suggest a good not too expensive PSU. Thx.

This has been discussed multiple times in the past.

Here are a couple of places to begin to understand the issue and find a possible solution.

Also, you may consider using a later, lower power CPU such as the Thoroughbred or Barton cores (or even Geode) now that you are getting a new motherboard. The Palomino 1900+ is on the higher end of the consumption.

@GarretW Thank you very much!

leon22 wrote on 2023-10-21, 20:27:

Thx CharlieFoxtrot. Maybe this mod is already enough Re: Socket A Motherboards That Have 12V-Centric VRMs??

Hmm. I don’t like that mod because it draws 12V for everything through one pin in the ATX20 connector, unlike when it would use P4 connector for CPU.

Will this be truly an issue? Not necessarily and depends on the configuration, but I definitely could see a heat issue issue with strong current draw scenario.

I will not do that mod. A friend had a spare PSU with 30A on the 5V line and I will use this one with the new board as the original Asus A7A266 no longer works (possible
fried when the old PSU died).

If it boots with FSB jumpered to 1oo, (might not have a jumper on that board tho) then you can be fairly sure it's a power problem on the board, bad caps, or PSU not supplying enough or clean/onspec enough power. Though not booting at 100 doesn't rule those out still.