Piggyback 4164 to Diagnose Memory Fault

[t0nyt]

Am going to change IC16 as a last throw of the QL dice

[t0nyt]

Am going to change IC16 as a last throw of the QL dice

Oh well, it had some effect but Minerva is still complaining about IC8

Will now break up for spares and just keep an eye on eBay for a replacement mobo

Thanks for all the advise

[Chris_68]

Hi,

Sorry to hear, if you replaced the logic circuitry and the RAM that throws an error plus cleaning up the solder joints I have no further ideas.
But, if you planning to get another MB then wait to break up this one. With some luck you can by swapping components find the error and repair it.

[t0nyt]

Hi,

Sorry to hear, if you replaced the logic circuitry and the RAM that throws an error plus cleaning up the solder joints I have no further ideas.
But, if you planning to get another MB then wait to break up this one. With some luck you can by swapping components find the error and repair it.

Will do. Am going to pack up all my QL stuff, until I find one, so will put it back in its case to protect it

Thanks for teaching me how to replace chips properly!

[Popopo]

Am going to change IC16 as a last throw of the QL dice

Oh well, it had some effect but Minerva is still complaining about IC8

Will now break up for spares and just keep an eye on eBay for a replacement mobo

Thanks for all the advise

You (perhaps) are blaming to the wrong IC.
Instead to look to RAM ICs... put an eye on multiplexers that are in charge of addressing the memory

[t0nyt]

Am going to change IC16 as a last throw of the QL dice

Oh well, it had some effect but Minerva is still complaining about IC8

Will now break up for spares and just keep an eye on eBay for a replacement mobo

Thanks for all the advise

You (perhaps) are blaming to the wrong IC.
Instead to look to RAM ICs... put an eye on multiplexers that are in charge of addressing the memory

Thanks, but am breaking the board for spares.

Having changed logic ic’s & some memory I’ve given up and have purchased a replacement motherboard.

[NormanDunbar]

Thanks, but am breaking the board for spares.

Ok, I'm not a hardware expert -- just ask anyone here -- but if you have not solved the problem, then breaking the board for spares is going to mean, I think, that you will never be sure if the spare part is working or faulty!

Just a though.


Cheers,
Norm.

[t0nyt]

Although I’ve given up on this board, I haven’t demolished it yet, but can confirm the zx8301 is good as it works on another board

Minerva still says IC8 is faulty, but can't be the IC as I've tried many and the socket all seems soldered ok with no shorts etc.