Apollo 1260 to a 1240 problems

[Kitch]

I recently bought a Apollo 1260, the 060 had died and the seller had fitted a replacement XC68040HRC25M CPU instead. The card arrived and seemed to work with the 040 fitted.
The strange thing is that it still has the 3.3V power converter board plugged in, if I remove the power converter board the A1200 just locks up with a black screen and when I refit the power converter board it works fine.
It also had a 66MHz crystal fitted when I got it so I decided to try a 50MHz crystal with the 25MHz CPU but it would black screen the A1200 so I tried two more different 50MHz crystals with the same result, going back to the 66MHz crystal and it would work fine.
I didn't really want an overclocked 040 so I decided to fit a 33MHz 040 CPU after I did that nothing would work so I tried a different stick of RAM and everything started working again and this time I could get it to run with either the 50MHz crystal or the 66MHz crystal.
Any ideas why the accelerator needs the power converter fitted for the 040 to work?

[roy bates]

its probably a 3.3volts 040,and the one your trying to replace it with is 5 volts.


removing the regulator leaves the cpu with 0 volts,you need to apply some jumpers so the cpu gets power.

[Kitch]

I don't think my chances of having two 040V's is very high.
The 33MHz 040 was pulled from a Mac so I doubt that it's 3.3V and both the 25MHz and the 33MHz seemingly work fine when the power converter board is fitted, benchmarks seem normal with the 040's fitted.
It makes sense that I might need to fit a jumper when the power converter is removed but I didn't see anything in the manual about that.

[roy bates]

if you like i can post a picture of where the jumpers are applied.


the reason the jumpers are not in the manual is very simple,there was no jumpers for the 040 card they where soldered to the board.(the 060 card has headers)

can you post a close up pic of the regulator board,front and back please just to see if its been bypassed in some way.

[Kitch]

I've attached a couple of photo's of the power converter. I hope they are clear enough.
I'm guessing for some reason the power converter isn't putting out 3.3Volts.
Ideally it would be good to get the accelerator working with an 060 but at this stage I just want to try and figure out what going on so that I don't damage any parts now or in the future.

[roy bates]

in this picture you will see the jumpers for 5volts operation.(you will need a multimeter for testing,and be very carefull)








in this picture you will see where to test if the regulator is putting out 3.3volts.












the test points are the pins to the right of the picture as you look at it(test points are the right top four pins for 3.3volts with this board and the bottom right two for ground),the left side is the input voltage which is 5 volts.


im sorry for the shabby hand drawn picture,i dident have much time.

[alexh]

Originally Posted by roy bates

im sorry for the shabby hand drawn picture,i didn't have much time.

You can see the jumper settings really easy on 1240 PCB photos.

http://www.amiga-hardware.com/downlo...1240_4_big.jpg
http://www.amiga-hardware.com/downlo...1240_3_big.jpg

You can see it matches Roy's diagram.

[roy bates]

thanks alexh,lol i never thought of that ive been in and out all morning.


EDIT:actually have you got a pic of your card,front and back please,can you take the picture at 90 degrees from the card so we can see it from above.

i have a strange feeling about this,as the card had a problem with an 060.

[Kitch]

Thanks for the diagram Roy.
I tested the power converter board at the terminals you indicated and I get 3.33 Volts, so does that mean my 040 is running at 3.3V instead of 5V?
I'll try and take photos of the whole accelerator in the next 30min.

[roy bates]

yes, it means the regulator is working and the 040 is running on 3.3 volts,to be honest i always thought the 040 failed below a given voltage that voltge being around 4.6 volts or so.
maybe its a slightly later mask,hmm i wonder.


im more curios about the actual cpu though because i thought that was a surface mount part going by the hrc in the code on the cpu.maybe im wrong hmm.

[Kitch]

Here are the photo's of the 1260

[Kitch]

Here's the photo of the XC68040HRC25M that came fitted to the 1260, I read somewhere here that the"H" meant that it was made by Hitachi?

[roy bates]

well it deffinitley used to be an 060 board.i would say a 50mhz model going by one of the surface mount parts(i'll explain this in a bit)

are you thinking of dropping in an 060 by any chance?

now about that surface mount part, if you look at the resistor at the position marked CLK under the cpu the resistor is in the spot next to GND to the right.this on its own doesent mean much untill you start going up the clock frequencys as this dictates the memory controllers ram speed in the position its in now its set to run at the same speed as the cpu.if you move it to the GND position it halfs and makes more speed possible.

[roy bates]

Originally Posted by Kitch

Here's the photo of the XC68040HRC25M that came fitted to the 1260, I read somewhere here that the"H" meant that it was made by Hitachi?

nope, thats a motorola part.

[Kitch]

Well now that it looks like the power converter is working I'll definitely look at buying a 060 to try in it.
Here's photo's of the 060 that original was fitted to the 1260 the seller provided it with the board.
I'll check the CLK setting when I get back from work.

[roy bates]

Originally Posted by Kitch

Well now that it looks like the power converter is working I'll definitely look at buying a 060 to try in it.
Here's photo's of the 060 that original was fitted to the 1260 the seller provided it with the board.
I'll check the CLK setting when I get back from work.

that my freind is a 75mhz lc060,and should never be used without a heatsink.
there is no-way that cpu board ever worked on that apollo with the settings it has now the ones under the cpu,go on ask me why


talking of heatsinks you should also have a heatsink on the 040 they get very hot.

[roy bates]

have a look at these,and tell me if you spot it

http://www.amiga-hardware.com/downlo...1260_5_big.jpg
http://www.amiga-hardware.com/downlo...1260_6_big.jpg


sure,the resistor is in the same place but in this position its more piccy about what simms work in it.

im wondering weither the card you have used to be a 50mhz or 66 mhz version and the person you had it off,got one of these addon cards that drop into the cpu socket(they where available seprately)

there was three models around from the factory as far as i know a 50mhz 060 a 66mhz 060 and a cut down lc75mhz model.(i suspect it used to be a 50mhz 060 board myself.do you know what it started out as by any chance?

[Kitch]

I'm guessing the seller removed the fan because there was a cut off tail coming from the power converter that looked like it may have been used to power a fan.
I've been keeping an eye on the temp off the 040 as I been testing and only using it for a short time. I do have a fan and heat sink but it's a bit large to fit in my desktop and may even have size problems in my tower.
Maybe 040's run cooler at 3.3V

[roy bates]

Originally Posted by Kitch

I'm guessing the seller removed the fan because there was a cut off tail coming from the power converter that looked like it may have been used to power a fan.
I've been keeping an eye on the temp off the 040 as I been testing and only using it for a short time. I do have a fan and heat sink but it's a bit large to fit in my desktop and may even have size problems in my tower.
Maybe 040's run cooler at 3.3V

it will definitley run cooler,if it runs at all
some 040's ive seen you can bearly touch them when there running i kid you not

[Kitch]

I'll look into this more after work, I'm running out of little jobs to keep my apprentice busy while I type. Thanks for all the help so far.