The Sinclair QL Forum

Looking at that pattern:

Reseat all the ICs. Look for a good, solid 5v across pins 1 and 3 of the 7805 during boot. Also check for a good, solid 5V somewhere down at the other end of the board. On the 68008 pin 13 is +5v and pin 35 is ground.

If you have a memory expansion, plug it in. If the failures happen only in the inbuilt RAM area and never in the expanded area, you can probably confine it to a component issue. If the errors also happen in the expanded memory, it could be a component OR power issue.

Do you have a capacitance meter? One or more of the caps may be dry.

Is dry caps enough of a problem for me to put together a "QL maintenance kit" of all the electrolytic caps so people can easily buy the complete set?

I checked the voltage of all the ram chips and the 7805 and is from 4.98 to 5 v ,I also checked the temperature of all the ic s including ram, and I think the IC21 74LS245 is a little warm, can this cause the condition since from what I read in the datasheet it has to do with data-bus?
Tassos

I also found this online http://hardware.speccy.org/reparar-i.html
Tassos

It being a cheap, easy to replace part, I'd try it just in case.

Tried a new 74LS245 but that was not the problem........
I am starting checking the memory chips now with Tobias method....
Tassos

ok it worked , minerva showed this
FFFFFFFF
7F7F7F7F
00030000
ok I used the Minerva ramfault_bas and the fault/faults are showing all over the place but mostly I see the above memory so I will de solder and resolder all the chip pins there.
Tassos