How to voltage mod A1-XE cpu module ? need 1.1 volt

Hello

The 7451 CPU on my module has cracked due to the pressure of my heatsink.

I accidentally bought an energy efficient version of the 7457 which requires 1.1 volt, (MC7457RX1000NB)
the lowest the XE can provide is 1.34 volt.

I'm thinking that changing a resistor on the module or motherboard may do the trick, but which one?


I'm inexperienced with eletronics, can anyone help me out?







If anyone needs a picture of a empty module:

https://s31.postimg.org/ei7psg4ej/Front.jpg
https://s31.postimg.org/sdalono7f/Back.jpg

The silkscreen on the front has discolored a bit with poor lighting (did my best!) making it a bit hard to read,
I think Hans de Ruiter so happens to have (or used to advertise on his site) a program to improve the white point in such images?

Look at page 10.

http://www.intuitionbase.com/a1_xe.pdf

1.59 and 1.44 are the only documented voltages but if you can measure them there are several available jumper configurations.

@Severin

There are more VCC_CORE settings in page 13 and 14

@HelloWorld

Yeah but looks like the range is from 1.244 to 3.54 so not much hope of 1.1

Does anyone know where I could contact the engineers of this board ?

@Helloworld

Hmm, the XE was developed and build by (now defunct) chinese company MAI and sold by (now defunct) company Eyetech.

You are probably out of luck contacting any of those...and even if you would, i doubt anyone would care

sorry

@Raziel

I doubt they would even remember it at all, wouldn't bother asking if I knew Mai was Chinese.


I'm going to prod the motherboard with a multimeter some weekend..

@Helloworld

I giess you alrerady know or have the AmigaOne XE manual?

Only two settings shown in there4, just with the original printed one i got with my board.

You have to be *very* careful, the chip is fried faster than the lifespan of a new character in Star Trek

@Helloworld

Do these lower power versions have good headroom for overclocking? Maybe you can take up the slack voltage by clocking the chip higher.

Crisot has done rework on the CPU modules so it might be worth contacting him to see if he has picked up any helpful info along the way.

@helloworld

Probably a silly suggestion but can't you reduce the 5 or 3.3 voltage BEFORE it gets to the cpu card so all the different jumper settings will also be reduced?

@Severin

Quote:

No, doesn't work that way. The CPU voltage regulator is very accurate and can tolerate large swing in the 3.3 or 5 or 12V input. 5V from the power supply isn't 5.00000V, it's more like 4.7~V to 5.5~V and swings wildly (in microsecond range) with the current load of the CPU. The CPU regulator's job is to make sure it deliver 1.34V at all times, if that's what it is set to.

@Deniil

That's the sort of answer I was expecting... didn't think a 'longer elastic band' would do the job.