I bought a cheap 464 untested.
When it arrived nothing on screen but power light was on and the screen brightened on boot, no del key sound.
Checked out this discourse between Bryce and Audronic. http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/repairs-to-a-cpc464/ (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/repairs-to-a-cpc464/)
The HD6845SP chip was pulsing on pin 25.
It is an MC0002a board which has a 40007 gate array and a spare 40010 socket space so I put in a socket took out the 40007 and inserted a 40010 that I took out of a 6128 I have.
Now it all works. :D
Does anyone know where I can get a 40007 or 40010?
I have recently gone through this hunt.
I managed to contact a seller that previously sold the 40010 and 40007, they didn't have the 40010 in stock. But he did put the 40007 back online fo r me.
Here is the link.
https://www.sellmyretro.com/offer/details/3874
My 40007 just arrived today and now i need to compare schematics to see what needs modding before the board will take a 40007 instead of a 40010.
Thanks for the link.I did not have to make any mods apart from installing the chip socket.
The mc0002 boards will run either chip.
But not both at the same time :-\