Power Tower A1200 with BPPC and other stuff not working properly.

[Daedalus]

Migatech, yes, the PSU is definitely something to be looked at, as I also said earlier in the thread. But it also sounds like you just had two problematic boards or setups. The behaviour you're describing isn't normal and perhaps pointed to problems with your setup somewhere, or maybe even the cards themselves.

A PSU's power rating has no real bearing on how good it is or what its minimum loading is. Your experience simply shows that one PSU was more suited to your setup than the other. Maybe the 350W PSU had a slightly higher 5V output, thus overcoming all the losses within your A1200. Or maybe it had better capacitors, so the ripple voltage at the CPU was lower. Or simply that the power requirements of your A1200 (even with a PPC board) were way too low to reliably operate the 500W PSU. You can't simply say that 350W is the magic number without knowing all the details.

[Capeview]

MigaTech, definitely not sending it off until I know for sure it's not an issue with the card. And if it means I have to leave it running all day to do something, I might have to do that.

I remember when I first got mine it was a hassle to set up and get working, and even today like you, I remember the hassles with getting various software working. It did improve when I got my 1d4 board though, but because it was the only one I ever had, I just kept it in the tower. And everything I have in the tower was pretty much from the off when I got the tower, but I do remember running it in a 1200 casing with the base plate out and slightly raised with a more powerful supply(No idea where that went).

I intend on changing the PSU anyway, probably go for a Corsair 350W as the 850W I have in my PC is just too much and don't want to blow something up if that could happen.

Plus, having a switch on the back of the PSU would be a bonus, because the power switch has a mind of it's own too. One time it will let me power it on, next time it just powers up itself and the switch does nothing.

Once I have my 1200's recapped, I'll be working on it again, and hopefully with a new PSU for testing and hopefully running the machine without issue.

[Daedalus]

As for the pins on the chip, they look like they've taken a bit of a bashing alright, but if it's working then there's no reason to think it would get any worse. Reflowing the solder joints might be an idea for peace of mind, and anyone doing a recap would be able to do that for you. If there's corrosion in the area however I would try to see where that's come from and stop it from spreading. It's hard to see in that photo if there is some sort of corrosion or whether it's just dirt...

[Capeview]

Really appreciate the help you guys. Learnt a lot in just the last few days.

I will update you when I get my 1200's back from recapping and new PSU running. I'm tempted to run the old PSU and see if it is the issue, but thinking I'll resign that to the Test Bench for my own recapping work I fancy doing.

Update. Zeb, the guy who is doing the Recap is going to have a look at it for me. He says it looks like something has been spilt on it(Bought from someone else years ago) but he says could also be a cap that has gone. He'll clean it up and investigate for me.

[MigaTech]

Originally Posted by Daedalus

Migatech, yes, the PSU is definitely something to be looked at, as I also said earlier in the thread. But it also sounds like you just had two problematic boards or setups. The behaviour you're describing isn't normal and perhaps pointed to problems with your setup somewhere, or maybe even the cards themselves.

A PSU's power rating has no real bearing on how good it is or what its minimum loading is. Your experience simply shows that one PSU was more suited to your setup than the other. Maybe the 350W PSU had a slightly higher 5V output, thus overcoming all the losses within your A1200. Or maybe it had better capacitors, so the ripple voltage at the CPU was lower. Or simply that the power requirements of your A1200 (even with a PPC board) were way too low to reliably operate the 500W PSU. You can't simply say that 350W is the magic number without knowing all the details.

Yes I agree with you on this Daedalus, but as Capeview explained the motherboard revision problems he had are the same as what I experienced. Not to mention this non functioning issue, which I have had on both cards. This is why I changed from a 2B to a 1D4. Also why I offered him the information further up the thread on Board revisions.

I know you know your stuff Daedalus so I am not saying you are wrong, I am only trying to get my experience of these cards over. Like I said even from brand new the card would take a little time, to get booting. It wasn't just plug and play like normal Amiga accelerators. I have been an owner since they came out and experienced a lot of strangeness over the years. I am glad Capeview explained his difficulties because it doesn't just look like I am going on with myself.

As for the PWR supply, this is why I asked you further up the thread if the 5v against 3v, makes a difference? As my BPPC is a 040 and Capeview's is a 060.

[Daedalus]

Strangeness like the card fundamentally not working is not normal, plain and simple. It might be poor contacts somewhere, a cracked or cold joint that closes when the PPC gets hot, or something else along those lines. Or motherboard issues, power issues etc. But it shouldn't be considered normal just because you've put up with it for 20 years.

Ah, I didn't see that small bit about the 3.3V versus 5V. It will make a bit of a difference in that the 060 consumes less power than the 040, but the difference isn't all that great in the grand scheme of things - a Blizzard PPC board still uses less than 50W even with an 040, so both cards are still in the range where they might not consume enough for a modern PSU to work correctly. If anything, the extra power consumption of the 040 might make it marginally more reliable on such a PSU, but either way, running that close to the minimum isn't a good way to be. Also, you need to consider that the 5V rail has been secondary on PSUs for many years now. 3.3V was the primary output for a long time, and these days 12V is, neither of which are used for the CPU(s) in an Amiga. So extra load on the 5V rail will make essentially no difference in those cases.

[MigaTech]

Interesting! Thought you would offer good information to that question, which is why I asked it you in the first place. Even if I did have to ask you twice!

As for the BPPC its not about putting up with it Daedalus, this happened from NEW! I have to say that once you get it stable and just leave it alone, it pretty much boots every time. It is just prior to this where the problems begin. With exception of the in OS software of course.

Phase 5 made great Accelerators and my Blizzard MKIV 030 works superb, I even like the blue streaks across the screen on boot up. so why the BPPC cards had issues from the outset? OK so they are more complicated but why this temperamental behaviour? Did Phase 5 miss something?

[Capeview]

My 060 card has never had any issues and has been solid if a little less compatible due to it being an 060. 030 and 040 were definitely the better cards for that, I just wanted the speed. I feel the need for speed.

As for the BPPC, definitely had similar issues like MigaTech but this is the first time I've had the card fail to do anything on boot up.

Seeing as both my 1200's have been sat around for ages, and the BPPC could indeed be a bit more problematic on the expansion slot, like daedalus said, it could just be a dry joint or broken something somewhere. Without the knowledge or equipment to check I won't know for sure, until I at least get my 1200's recapped and a replacement PSU just to see if that fixes the issue or not.

I may test the old PSU to see, but will have a new one as well.

Thinking of possibly going for this one

https://www.scan.co.uk/products/350w...mm-fan-atx-psu

Been satisfied with my PC PSU and it's extremely quiet, but I know PC and Amiga requirements can be different beasts, so anyone any ideas?

And using the Mediator won't be a problem as it already comes with a 10 pin ATX style connector, just hoping the rails are sufficient?

[indigolemon]

Hi Capeview, I'm using a 400w Corsair supply in my tower setup - although mine is just a 1260. A CMPSU-400CX to be precise, pleased to say I've had exactly zero issues with it

Does your mediator have the ATX connector along with the AT one?

[Daedalus]

Yeah, that PSU will be a decent quality one, but just bear in mind what I was saying about the power consumption of the Amiga. From looking at the basic specs of it, the primary rail is most likely the +12V line (it's by far the heaviest rail). It would be best if you could find out what the minimum current draw requirement is on that, because it's highly unlikely the Amiga will meet it. The power output will be far more than sufficient (I suspect a fully loaded PPC Mediator setup probably still only uses about 50W on the 5V line) - it's the minimum required load that's a potential problem. Adding extra load to the +12V rail might help to reduce any problems...

[Capeview]

indigolemon, the mediator I have is the original one, the 1200 with 4 PCI slots and two white connectors called p8 and p9, each with roughly 6 cables in a line connected to an ATX style cable on the other end that you then connect to the ATX Power Cable.

The newer mediator boards seem to have both these connectors on the actual board themselves now. Seems they may have improved the power control on these boards to work better without draining the Expansion Port.

Daedalus, So what you're saying is the ATX PSU needs a lower or higher rating on the 12v rail?? And I'm assuming that the 5V is where the 1200 draws most of it's power from so meaning it needs to be higher??

I'm still learning. PC's are fairly easy.

[MigaTech]

@Daedalus what a storming idea! Are you surmising all 4 of his PCI slots populated? Would it make any difference if all devices were running simultaneously? Including HDD's and CDROM's etc.

I am guessing his Mediator to be either an LT or LT4 although they didn't have ATX only AT. The SX and the TX did but they were 6 PCI. That said of the 3 Mediators I own, one from 2005 has updated MACH chips, that is still AT and 4 PCI..

@Capeview have you updated your MACH chips?

[indigolemon]

Originally Posted by Capeview

indigolemon, the mediator I have is the original one, the 1200 with 4 PCI slots and two white connectors called p8 and p9, each with roughly 6 cables in a line connected to an ATX style cable on the other end that you then connect to the ATX Power Cable.

Got you! Yeah that makes sense to me, as was sure the original mediator was AT (the P8 and P9 connectors)

Originally Posted by Capeview

The newer mediator boards seem to have both these connectors on the actual board themselves now. Seems they may have improved the power control on these boards to work better without draining the Expansion Port.

Yeah, I splurged on a TX and have both connectors, made the power supply swap easier, and also allows for 3.3v PCI cards to work (which is nice).

Originally Posted by Capeview

Daedalus, So what you're saying is the ATX PSU needs a lower or higher rating on the 12v rail?? And I'm assuming that the 5V is where the 1200 draws most of it's power from so meaning it needs to be higher??

Some PSUs struggle to maintain the correct voltage unless there is a suitable draw on a given voltage rail. This can cause problems using new PSU's with older kit. Do you have a mechanical hard drive in the tower? Most Corsair supplies are happy at 10% load or above. Some of them even have a 0v minimum load!

[Capeview]

Here is a picture of my Mediator. It shows the cabling too.

The cable with the Purple, Black an Grey with the floppy style connector plugs into my Keyboard adaptor which connects over the chip near the Keyboard Ribbon slot and runs to an external Keyboard adaptor and the runs Power and Reset cables to the front of the machine.

[Capeview]

Originally Posted by MigaTech

@Daedalus

@Capeview have you updated your MACH chips?

I believe I did along time ago which is why they have the labels on. Don't know if there is another update or software update, but I'm sure the Mach chips were updated for software and hardware compatibility or something.

[Daedalus]

The maximum of the rails isn't directly important, once it's enough to power the system. There's a second specification of minimum load that typically isn't included in the standard specs, but can often be found in the detailed specs or data sheet if that's available.

Modern PCs need most of their power on the 12V rail, which is why the PSUs are made to match. They assume a certain minimum load on the 12V rail and are designed around that. The other rails are typically a fixed ratio of the primary rail, so if your 12V rail isn't right, the 5V rail won't be either. That's why the minimum load is important for Amiga use and not really a consideration for PCs.

Hard drives, especially old hard drives, will use 12V and that's a good way of loading the rail. PCI cards *might* use 12V, but typically not enough to make a difference so loading it up won't make much of a difference in that regard. CD-ROM drives are less useful for this because they only use the power when they're actually running.

The minimum load usually isn't huge, perhaps 1 amp. Any modern GPU or CPU will easily use more than that, but an Amiga won't. An alternative option is to fit a dummy load, such as a resistor. A 10 ohm resistor across the 12V rail will pass a little over 1 amp, though it will need to be of a high rating, perhaps 20 watts. It will get very hot as well so best that it's bolted to the case. But something like that will ensure that the minimum load is met for most PSUs, and will be silent.

[Capeview]

Originally Posted by indigolemon

Got you! Yeah that makes sense to me, as was sure the original mediator was AT (the P8 and P9 connectors)


Yeah, I splurged on a TX and have both connectors, made the power supply swap easier, and also allows for 3.3v PCI cards to work (which is nice).


Some PSUs struggle to maintain the correct voltage unless there is a suitable draw on a given voltage rail. This can cause problems using new PSU's with older kit. Do you have a mechanical hard drive in the tower? Most Corsair supplies are happy at 10% load or above. Some of them even have a 0v minimum load!

When my tower is fully built, I have a 3Dfx Graphics card that is powered from a seperate molex? connector, a sound card, Network card, a 3.5inch HDD, CD drive, floppy drive and if I can get it working again, Fast ATA controller.

Obviously intend to change or alter some of this if when I get OS 4.1 installed I can go with a better GFX card, SSD or something similar and possibly a DVD in place of CD as I still have disks i like reading.

As I've been testing and removing I don't have any of this installed. So are we saying I need to fully populate and that could give the PSU the draw it needs to run properly?

[Capeview]

Originally Posted by Daedalus

The maximum of the rails isn't directly important, once it's enough to power the system. There's a second specification of minimum load that typically isn't included in the standard specs, but can often be found in the detailed specs or data sheet if that's available.

Modern PCs need most of their power on the 12V rail, which is why the PSUs are made to match. They assume a certain minimum load on the 12V rail and are designed around that. The other rails are typically a fixed ratio of the primary rail, so if your 12V rail isn't right, the 5V rail won't be either. That's why the minimum load is important for Amiga use and not really a consideration for PCs.

Hard drives, especially old hard drives, will use 12V and that's a good way of loading the rail. PCI cards *might* use 12V, but typically not enough to make a difference so loading it up won't make much of a difference in that regard. CD-ROM drives are less useful for this because they only use the power when they're actually running.

The minimum load usually isn't huge, perhaps 1 amp. Any modern GPU or CPU will easily use more than that, but an Amiga won't. An alternative option is to fit a dummy load, such as a resistor. A 10 ohm resistor across the 12V rail will pass a little over 1 amp, though it will need to be of a high rating, perhaps 20 watts. It will get very hot as well so best that it's bolted to the case. But something like that will ensure that the minimum load is met for most PSUs, and will be silent.

I'm seeing people using Meanwell power supplies in there old A500 and 1200 power units. Would one of these be a better fit in place of the power supply inside the ATX PSU?

Obviously, trying for the easy option because soldering or adding in isn't something I've really done but will have a go if I need to, would just need to find out how and any pointers. I'm no electrical engineer and don't want to blow anything up.

[hese]

Originally Posted by Daedalus

It's possible for chips like that to lose their programming over time, although difficult to diagnose without replacing or reprogramming them. There are people who possess the skills and equipment to do such repairs - Chucky and Stachu are two that come to mind.

That's quite tiny and outdated list of repairers, should be updated. Neither of them can reprogram the MACH chips of BPPC if the chips are faulty. The only choice is to take working MACH chips from another BPPC.

[Daedalus]

Originally Posted by hese

That's quite tiny and outdated list of repairers, should be updated. Neither of them can reprogram the MACH chips of BPPC if the chips are faulty. The only choice is to take working MACH chips from another BPPC.

My mistake - I'm sure I remember them talking about reprogramming the chips but perhaps I'm just remembering them swapping chips. That's a big shame - do you know anyone who can do it?