Choosing a new ATX power supply for an expanded Amiga 4000

[Daedalus]

Originally Posted by Hewitson

If you don't fear it, then you shouldn't be working anywhere near it!

Even the best electricians are scared of electricity. It's one of the most dangerous things on the planet.

Don't confuse fear with respect. Fear causes irrational thinking and mistakes, which can lead to death with electricity. Respect for electricity and its dangers is what keeps electricians safe, not fear.

[AC/DC HACKER!]

Mistakes are a funky "belief" system many people take on through teachings from others. A choice creates another choice, and if you reject the "believe" of mistakes you can learn better without the judgement of others or harshness of yourself taught by others. I agree with irrational thinking, but not with mistakes. Not all choices carry hindsight ahead of them by people.

Thanks to Paul Rezendes (ACILL) my adapter from Amiga-Kit is now powering my A4000 + CSPPC, CVisionPPC, Picasso 4 and more as it should. If anyone is in the States and not practiced enough with this stuff and much more, he's a great choice and very cool with prices. Big thumbs up.

[spudje]

@Trixster what exact system are you using this PSU on? And what ATX adapter did you get? I'm considering replacing my PSU in my A4000 CSPPC Mediator (3V) & Voodoo setup hoping to make these freezes belong to the past.

Would a 450W Corsair or even the BeQuiet SFX Power 2 300W be sufficient?

[trixster]

Corsair SF600 SFX power supply. Grelbfark is using the SF450

I believe it’s not really about the wattage (as all these psus have more than more than enough juice to power even the most loaded Amiga), it’s more to do with having a good 5v line (which is ideally not taken from 12v) with plenty of amps which do t drop when loaded.

[spudje]

Yes, and how do you feed it to the A4000 mainboard, which adapter? I talked to Chucky, who made my current ATX PSU. He said, maybe feed additional 5V INTO the Amiga via the CSPPC fan connector? Sounds a bit scary? Or could I simply do that, maybe even with my current Chucky ATX PSU?

[trixster]

I'm using the AmigaKit ATX adapter which seems to work fine, although it'd be nice if the wire guage was a little thicker. You can 'inject' 5v a number of ways from a molex - I guess via the CSPPC fan is one way. I have a spare ramix which i've modded by adding 5v and gnd lines to a molex at the fan connector - that way i can inject 5v into the mediator, although it's not really needed. Somthing to be aware of maybe is overvolting (or crowbaring) but thatdoesnt seem to occur here.

[AC/DC HACKER!]

Originally Posted by spudje

@Trixster what exact system are you using this PSU on? And what ATX adapter did you get? I'm considering replacing my PSU in my A4000 CSPPC Mediator (3V) & Voodoo setup hoping to make these freezes belong to the past.

Would a 450W Corsair or even the BeQuiet SFX Power 2 300W be sufficient?

Originally Posted by trixster

Corsair SF600 SFX power supply. Grelbfark is using the SF450

I believe it’s not really about the wattage (as all these psus have more than more than enough juice to power even the most loaded Amiga), it’s more to do with having a good 5v line (which is ideally not taken from 12v) with plenty of amps which do t drop when loaded.

Originally Posted by spudje

Yes, and how do you feed it to the A4000 mainboard, which adapter? I talked to Chucky, who made my current ATX PSU. He said, maybe feed additional 5V INTO the Amiga via the CSPPC fan connector? Sounds a bit scary? Or could I simply do that, maybe even with my current Chucky ATX PSU?

I went with the 450W Corsair because of size fitting into the A4000 case. I'm also using A400 ATX adapter from Amiga-Kit that Paul Rezendes modified to get more correct power from. What kind of freezes are you noticing? Since the update to PSU and ATX adapter I've had some also. PPC is displaying my Workbench image, and passes images from WarpDT and other WOS Datatypes very well if I select a bunch at a time, not going past memory limit...and keep repeating. But if I play Payback PPC or ShogoMAD for 6 to 35 minutes..freezes or crashes happen.
I've used the note in WarpOS update for CyberGraphX V4 for ENVARC:PowerPC but hasn't help. For a while the PPC was doing great. Now I'm seeing #80000004 and #8000000B erros when I have those loaded. I'm very careful about static when touching hardware...and very, very careful about adding and removing the CVisionPPC from it...and I rarely do that.
You might need your CSPPC to be checked, as I might.

[spudje]

See this thread about my struggles. http://eab.abime.net/showthread.php?t=100763

I think it's mainly a power issue, maybe combined with heat. But I'm not handy enough myself to fix up a PSU and connect it to the mainboard/mediator via multiple connections myself.

What did Paul exactly do to your adapter?

[AC/DC HACKER!]

I'll read that link in a moment. He modified the V5 line - combined more to it. Simple explanation. When I got the ATX adapter from Amiga-Kit ( http://amigakit.amiga.store/product_...roducts_id=615 Mine has the black "Amiga" connector, so the images have changed) it wasn't supplying enough power. I had was noticing a lot of crashes also. As well as some interesting flickers, screen "static" when I'd screen Amiga screen up and down... Usually from my self-made Boot menu. But yeah, Payback PPC, Shogo MAD, Wipeout 2097 were crashing or freezing often. Until I sent it to Paul because I don't see colors the way most do...I also don't understand those kind of voltages well and I didn't want to goof anything. So, he altered the ATX adapter and it has been going well for a while.

As I've been able, I've been troubleshooting. I think the 68060 has come loose or the socket needs to be redone. I thought I was chasing over heating from the PPC. But I've just started testing running AmigaOS 4.1.1 which disables the 68060 and uses ONLY PPC. So far Payback PPC (ignoring the guru and SDI hit..) has been doing well in my first test. It has lasted more than an hour now just sitting in 1 spot letting "cars" go by...and my once in a while moving the character or car around. The "Source" and "Destinaition" color balls are flashing as they should.

I'll read your post more soon, and reply again. I hope this help you and perhaps someone else. If anyone has further insights or experience to add, I'm also, of course, open.

[AC/DC HACKER!]

Paul Rezendes is Acill. YouTube: https://www.youtube.com/user/Acill He's in the U.S..

[spudje]

Thanks for your own experience. Seems similar. Although I doubt mine is 060 related as I remember I could run Quake 060 in Warp3D without issues. As soon as I ran the WarpUp version it started freezing. Non Warp3D things work fine on PPC.

So think it's the combi of the PPC & Voodoo in 3D in use drawing too much power.

[AC/DC HACKER!]

Originally Posted by spudje

Thanks for your own experience. Seems similar. Although I doubt mine is 060 related as I remember I could run Quake 060 in Warp3D without issues. As soon as I ran the WarpUp version it started freezing. Non Warp3D things work fine on PPC.

So think it's the combi of the PPC & Voodoo in 3D in use drawing too much power.

You're welcome. That's possible. I read your thread, and it does seem power related. Payback PPC with OS 4.1.1. (since it crashes with my enhanced OS 3.5.., a lot of WOS parts in place vs 68K) has been running stable for 2 hours now...as of this reply. In my recent days of troubleshotting that has Not been so for OS 3.5. Often not making it past 35 minutes.


A4000D - Top to bottom:

X-Surf 100 Z3 Enabled
BigRAMPlus (256)
Empty

Picasso 4


Then CSPPC, fan on PPC, and I've shifted RAM around a bit. I've also copied from CompactFlash to RAM a lot, then delete from RAM, fill RAM.. Made a simple script to do it over and over and over sgain. Not any problems. So CSPPC RAM is fine, Motherboard 16MB RAM all removed. Only Chip left onboard.


CVisionPPC is still connected. I was taking it off at times because with it connected the Amiga's 68K is a Little slower. I think what happened is I pulled a rookie error, and while the Amiga had been running for a little bit, and I added the CVisionPPC back to the CSPPC while still warm..and that affected the 68060. (Shit!) HAHA! I didn't press hard, I'm usually very, very careful. But...perhaps?


Looked behind me, and I see the yellow pointers to the dummies in the game to be shot are still pulsing and alternating from one to the other. I think I found the problem... Maybe those are green arrows? Shades are very challenging for me.


Anyway, be SURE it's not your 68K! I agree with that advice...strip it..and really check it. Don't rely on 1 to 5 checks, keep going. You want consistency. When it comes to electronics that's very important. Haha, even our beloved Amigas.


I have 1 Other possssssible wonderment. There's a Heat Sink without a fan on my 68060.. I'm really thinking of removing that as it could be trapping rather than releasing heat.

[spudje]

Thanks!! I reached out to Paul, let's see what he has to say What about modern PSUs needing load on the 3,3 V line, etc. to be stable?

[Daedalus]

Modern PSUs tend to run the 5V and 3.3V rails off the same internal supply, so once one of them is loaded to the minimum, the other should be fine too. However, the governing output on modern supplies is typically the 12V rail, of which even heavily expanded Amigas consume very little. So a dummy load could be required on the 12V output in order to stabilise all the other outputs (including the 5V rail critical for the Amiga), depending on the minimum load requirements of the PSU.

As for the comments on combining outputs, it's possible that that can help too - some PSUs have monitoring on some of their output lines but not others, and if one is used and another not, that can help bring it all into balance. However, some PSUs have entirely separate supplies that are not to be cross-connected, so you need to be sure about your PSU's design. If it has designations like 12V1, 12V2 on its output for example, they generally shouldn't be connected together.

[Toni Wilen]

I'd only call PC PSU modern if it uses DC-DC internally (has big 12v output and 3.3v and 5v is generated by DC-DC converters from 12v) and does not have minimum load requirements ("Haswell ready", almost no load on 12v: 3.3v/5v still works normally). Group regulated PSUs are not modern anymore in my opinion

[spudje]

So which PSU should I get, that allows me to combine 4 5V cables? One of these: Corsair SF450 or the BeQuiet SFX Power 2 300W ?

[grelbfarlk]

An ATX 24-pin connector has Five 5V pins while an ATX 20-pin has Four. Though you shouldn't need that many. I get by on a heavily loaded A4000 with just two 16 gauge wires going into the same 5V pin on the motherboard. That's with a Ragnarok@950MHz, Voodoo 3-3000, NIC and SB128, Warpengine 060/66MHz 128MB with 64MB on the Motherboard, DVD, CF Card Reader and a 120GB SSD (though I had a 15000 RPM 300GB SCSI drive in there too which worked fine). Total system load is something like 95W while running Quake 3. SF450 is not totally ideal since the 5V rail is probably at 80-95% of maximum, but it works fine and has for the last 3-4 years.

If you go with the SF450 be sure that you pick one of the 5V pins on the ATX connector that has two wires going into the connector.

[spudje]

Thanks!

With

If you go with the SF450 be sure that you pick one of the 5V pins on the ATX connector that has two wires going into the connector.

, you mean, I need to take 2 5V wires from the ATX connector running to the 1 5V connector of the A4000 plug, correct?


So if I would go for the Amigakit adapter, I'll have to mod it, routing more 5V cables to the PCB connector (I can run 4 in total I think).

However, weird thing, the current ATX PSU I have, modded by Chucky, already has 2 5V lines combined and 2 +12 V lines combined in the PCB connector. I checked this yesterday. So either this still isn't enough (as the original A4000 PSU has my A4000 still running more stable, or should I say less unstable), or I'm facing another issue after all (Heat, Mediator??).

Too bad I haven't got a multi-meter (yet), otherwise I could verify voltage drops along the way.

[trixster]

I think it’s worth noting that I’m using the amigakit adapter with an sf600 and I haven’t modded anything to add more 5v lines. My machine is as loaded as they come and I’m not seeing any power issues.

My ICY V2 zorro card measures the voltage drop at the busboard and reports that 5v will drop to around 4.6v - even with this I’m not seeing any problems. If I add an injector from a spare molex (either through a modded Ramix 239/F or a wired up molex connector inserted with a breadboard directly into the busboard, the voltage only climbs to 4.7ish volts

I get the impression that power distribution around the A4000D isn’t particularly good, and as such even splicing in extra 5v connectors or 5v injectors can only go so far to rectify any issues

[AC/DC HACKER!]

Originally Posted by spudje

So if I would go for the Amigakit adapter, I'll have to mod it, routing more 5V cables to the PCB connector (I can run 4 in total I think).

However, weird thing, the current ATX PSU I have, modded by Chucky, already has 2 5V lines combined and 2 +12 V lines combined in the PCB connector. I checked this yesterday. So either this still isn't enough (as the original A4000 PSU has my A4000 still running more stable, or should I say less unstable), or I'm facing another issue after all (Heat, Mediator??).

The Amiga-Kit adapter wasn't enough for my A4000D with all the extras I have. Once Paul modded it the 450W Corsair has been great. It fits in my A4000D case very well also with the printed 3D part. Before the mod to the Amiga-Kit adapter it wasn't getting enough power.

Originally Posted by trixster

I get the impression that power distribution around the A4000D isn’t particularly good, and as such even splicing in extra 5v connectors or 5v injectors can only go so far to rectify any issues

That'sssss intriguing.