Help to fix a 6128

[ayasystems]

Hi
I have a broken CPC6128.




I have change all memories because some of this were hot... then the amstrad seems to start but not completely


I have put out the 40015 and without it the cpc is showing READY



I put other 27c256 from my good 6128 and it is not showing READY again.....


What could be the problem?


Any idea??

[Quickie]

Hi,


Before swapping the memory chips, did anything appear on screen?


I'm not very experienced and have never come across this particular failure, however I would start checking the /RESET line. Is it on high state?


Saludos!

[tjohnson]

Hi,


Before swapping the memory chips, did anything appear on screen?


I'm not very experienced and have never come across this particular failure, however I would start checking the /RESET line. Is it on high state?


Saludos!

Good question was the CPC working before you started removing memory.

[Bryce]

You've put a 16K image on a 32K EPROM. But A14 (pin 27) is tied to VCC (pin 28), so the CPC is looking at the upper 16K of the EPROM, while your image is in the lower 16K of the EPROM. Try using a 27C128 instead, or if you don't have one, burn a 27C256 with two images of AMSDOS, one in the upper 16K and one in the lower 16K.

Bryce.