The way I fried my BPPC card.

[PiR]

Listen to my very interesting story about the way I fried my BPPC card two days ago.
People willing to play with the Power can learn some from this.

Well, I have problem with power from the very beginning of my BPPC. During startup my Amy freezes before full WB getts started, at random moments. Luckilly for me after the temperature getts higher after some time it, starts working quite stable.

But this startup was getting on my nerves! :madashell:
When the mashine froze I could hear the fan getting slower. Yeah, deffinetly power problem.

I did some tests with multimeter. Strange thing - I've discovered that on 5V from the PSU to the PCB I was loosing 0,14V, while from the PCB entry to froppy connector I was loosing only 0,07V. So till floppy power connector I have over 0,2V dropping, but most of the power is somewhere inside cable + socket () BTW: I have strong PSU from Micronik, and Amy still in desktop.

On Sunday I decided - I'll connect the cables to the fan connector of BPPC! I connected GND and +5V from the main power socket. Started up. Well, it worked!  :-D

On Monday I figured that fan is not working. I got nervous. I took out my freshly bought 128MB SIMM and HOLLY COW! What a mess did I find!  :-o
Some chips exploded, covering everything with black dust, and plastic desktop case has a burned out hole in the place it sticks to BPPC. What a nightmare.  :-(

Yesterday I picked my poor card. First thing was - well, it IS working!  :-) Only fan is not moving...

Closely placed tracks looks not touched.  :-)
Only those connected to those exploded thingies...
And those thingies are surface soldered resistors, mayby hard to fix, but not a big intelligence afterall... And the only thing they seemed to be connected to is the fan.

I picked up some cables and connected the fan to the floppy power supply. The trick worked!  :-) I put everything together again.

So, I still have this trouble with power again. Till my Miggy gets warm it freezes on startup. And funny thing - I can still hear the fan getting slower at that moment. But now it is connected to floppy power supply, not to BPPC, so the drop down is global for whole Amy and I thought that this edge connector can be big trouble.

Still I have to wait until I can do anything. But I'm extremally happy my BPPC works at all. 8-) I don't understand what happend and why. The most damaged resistor is on the track closer to GND than +5V.
I won't mess around with my BPPC any more. But only the Devil knows whats happening inside my PSU cable + socket... :-(


And they lived happily ever after.

[odin]

You mean......you blew up your Bliz and it kept on working???

My god....A1200's really are frankenstein machines :-D.

[patrik]

@PiR:

As the fan is still going slower when it is directly connected to the power supply, I would suggest that your power supply is a bit dodgy.


/Patrik

[lempkee]

pir: are you 100% sure you connected it correctly and that it was 5+ Volt ?.

if you mix this then u will get problems ...

anyway i am glad to hear it still works but there was some parts in your post i didnt understand, want to try explaining it again?

[Kronos]

Could it be that what exploded wasn't a resistor, but a capacitor you had feeded
a wrongly polarized voltage in by your trick ?

[PiR]

@Patrik

The dropping is only on Amy board I've checked the voltage inside PSU and its quite over 5V.

@lempkee

I've checked several times several things. I was not going to risk my precious! I've checked the voltage, when on-power, I've checked the resitance from one point to the other when off-power... I've checked the direct voltage (+5V and GND) and cross voltage (one pin from one point and the other from the other....)

What can I clearify more?

My checking points:

PSU (+12, GND, +5) : never under 5V

Amy Power socket on MoBo (+12, shield, GND, +5, -12) : hard to reach... Made shortcut once during tests... My PSU works tricky now after such experience ;-)

floppy power connector on Amy MoBo ( +12, sheld, GND, +5) easiest place to check; 4,8 when it's working, can drop till 4,65 on freezing...

BPPC fan connector (+5, GND): whats the difference? Its even further to PSU than floppy...

@Kronos

I could be better in present electronics, but I'd bet capacitor of valuable size should be bigger... Well, every guy with BPPC can check three thingies next to BPPC fan, on the other side.

[amigamad]

Thats serves you right manuel says tower case only it probaly got to hot in a desktop.

[patrik]

@PiR:

I dont mean the voltage drops caused by the resistance in the cables and the motherboard power supply lines. When you hear the fan loose rpm temporarily when it is connected directly to the power supply it cant be the cables. The resistance in cables could only cause a constant lowering of the voltage and alas fan rpm.. and a cable with great enough resistance for that when powering a little 5V fan would probably have to be as thin as 0.01mm. What I am trying to say is that it definately sounds like your power supply is acting wierd and I would urge you to try another one... if it doesnt sound like a good idea to you, atleast consider doing it just for the sake of it.


/Patrik

[Lemmink]

If you have a 060 PPC you might get away with only pouring power into the system at one point. If you have an 040 PPC you absolutely must put extra power to the system via the floppypowerconnector of the A1200 board.
Is sure look ugly as hell haveing an extra powercord going into the machine through a crack in the desktopcase, but thats the only way to get a stable system.
So better put it in a Tower anyway.

[TheGoose]

What Lemmink just said is the absolute 100% correct way to run a B PPC card in a A1200.

And I'd only add that making a tower solution could solve many heat/power problems.

I made my own with a big old AT server case and it
worked out great. You just need some beer, dremel tool, ultra violence, heat, friction, a bit of cussing and
bleeding (you will cut open your hand) and soon you'll emerge on the other side, A1200Tower land.

BTW, my fan blew up too, everything still works perfect without it.
  :-D

[PiR]

Hi thanks for such a big feedback, I didn't expect it. :-)


@amigamad:
I know that sounds crazy, but I observed, that when my Amy is cold it won't work. When it gets warmer it starts working. I think that for some reason on the higher temperature either resistance or power consumption reduces.

So what is the purpose of increasing cooling, again?  :-)


@patrik:

That would be insane if just a cables had that big resistance. But what can you tell about the socket? I was trying to test it but it is too hard for me to access it (I mean internal parts of it). On the other hand this is the only thing that sounds logical to me. I've measured the voltage just at the other side of the power socket and observed the poor result, while having good values in soldering places in PSU. So either unlikely cable, or this stupid socket.
I have my original PSU. Also here I don't trust this socket, but that can be my self-sugestion, mayby I'll investigate it more deeply.


@Lemmink

Yes, it is 60. But read yourself and tell me - I'm insane and the Amiga power socket cannot be the source of the troubles... Attaching power to floppy connector is just omitting this socket.


@TheGoose

Did you blow your fan too? Do you also have 60? Mayby this is the rule - you just shouldn't do it for 60?
Am I wrong, or 60 in BPPC works under 3,3V, while 40 really uses 5V? Hmmm....

[Lemmink]

Belive it or not but since the BPPC draws way more power then the A1200 expansion connector was originall build for you just have to give some extrajuice to the board via the floppypowerconnector.  On the way from the A1200 Powerconnector to the expansionconnector some power is lost, depending on the shape the board is in it will be more or less.
Feeding power to the board by two ends increases the amount of power that actually reaches the expansionconnector.

[Brian]

I had an A1200 desctop with BPPC040 and it worked sortof with a converted 200W AT PSU. If the CPU load was higher than idle the mouse pointer graphic would start jumping like crasy and if I accessed both internal and external diskdrive att the same time my 3.5" HD that i had inside would spin down and upp again. I soldered a "male HD power" connector directly on the motherboard where where the powerplug is and plugged in one of the powerplugs from the PSU and it worked like a charm, guess the floppypowerplug is just as good but not as good looking.

For my BPPC I had added an extra coolingplate and fan for the 040 and cut out holes for both coolingplates in the trappdoor aswell as added feets to lift ut the computer some (fan stuck out about 1cm underneath the computer).

Now the hole lot is going into a tower though. :-D

[PiR]

Hi

@Lemmink

I know, I know... But:
If you look at my first entry you'll see that I'm losing much more power (more less twice as much) on the way from PSU to MoBo (cable+socket) than really inside MoBo. Anmd belive me - I've checked it really carefully a lot of times as I couldn't belive it.

And now my fan is juiced from floppy connector and behaves EXACTLY THE SAME as when it was connected originally to BPPC. So, again also huge surprize for me - edge connector is not the main player.

To be honest - Amiga power socket was also designed for different power consumption, so 'is allowed' to cause troubles...

I have a board ver.2B, and my HD had to go off the desktop case exacly the same day my BVision arrived - unluckilly no place for both inside the case.

Luckilly for me, my Micronic PSU, appart from normal Amiga power connector has additional HD-like power conectors, so I powered HD and CD from there, not from MoBo. Frankly - this was also the most comfortable place to measure the voltage produced by PSU. And I don't have any troubles with either HD or CD.

@Brian
In my case I have a feeling that much VRAM manipulations can cause my machine to freeze (screen opening, Window moving - squares of data to copy, when machine is very cold at the beginning even text manipulations can be risky).
No, I won't add any cooling to the system... I want it to get hot and operational as soon as possible (mayby even extra heating at startup?  ;-) )

[patrik]

@PiR:

Atleast give lemminks suggestion a try even if you dont think it will help. If it for some reason wouldnt do any good, it wouldnt make things worse.


/Patrik