Opus Discovery 1

[t0nyt]

I don't believe it

I got it all working with a gotek & floppy drive (had to replace the one that was in it. as it didn't seem to work, with a spare I had)

I then put the outer lid back on and now it doesn't work

This time the speccy is getting power as it tries to display something (sometimes it gets to the boot screen but there's no indicator arrow from the opus), but the gotek isn't getting any power

Took the top back off but can't see anything obviously wrong

The only thing I noticed is there's a hum from the transformer which I don't recall being there when I had the lid off originally (but not 100% sure on that)

Don't really have any more time to look at this again this week, so will have to come back to it next week

[t0nyt]

It looks a bit like the new eprom I burned has failed (probably clutching at straws) looking at some threads on zx forums

While I wait for some replacement 2764's to arrive, is it feasible in a device like this, to use 27128's with the ROM loaded in the upper 8k please?

Many thanks

[XorA]

That's easy to test though, read the EPROM in your EPROM reader.

[t0nyt]

That's easy to test though, read the EPROM in your EPROM reader.

Good point!

Thanks

[t0nyt]

Extracted the ROM and it passed a verify check, so not that

I've since read that it's a known problem for the rectifiers to fail when upgraded to 2 disk drives (wish I'd noticed that before!) so will try replacing those (not a nice job by all accounts) when they arrive

Possibly explains why I've lost 5v to the GoTek

Many thanks

[t0nyt]

I thought I’d have one last look at this for now

I reseated the socketed ICs & with everything else disconnected it works again

So I screwed the plate with the floppy drives back on (without connecting them) and it stopped working

I removed the back right screw and it works again, re-screw and it stops etc etc

The motherboard is too firmly attached for it to be a break in that being stressed and so far I can’t find anything being fouled by the slight movement of the floppy plate when it’s screwed down

But am getting somewhere, just don’t know where currently!

[XorA]

I thought I’d have one last look at this for now

I reseated the socketed ICs & with everything else disconnected it works again

So I screwed the plate with the floppy drives back on (without connecting them) and it stopped working

I removed the back right screw and it works again, re-screw and it stops etc etc

The motherboard is too firmly attached for it to be a break in that being stressed and so far I can’t find anything being fouled by the slight movement of the floppy plate when it’s screwed down

But am getting somewhere, just don’t know where currently!

That sounds like that plate is flexing something and causing a short! look carefully for anything sticking out of the gotek, drives, etc!

[t0nyt]

That sounds like that plate is flexing something and causing a short! look carefully for anything sticking out of the gotek, drives, etc!

I think I've sussed the cause, now all put back together and still working!

When I inadvertently ripped off the regulator attached to the bottom of the floppy plate I must of also twisted the L bracket around (that the regulator attaches to as a heatsink) and when moving/pressing down the plate with the screw I think the bracket was coming into contact with the other regulator that sticks out of the motherboard

One of the joystick cables became detached from the mobo with all the messing around, but that's hopefully an easy fix for another day (am going to try a joystick adapter on the thru port anyway. I have several I can try)

The main job currently is to re-configure my gotek configuration so the display isn't upside down!

Fingers crossed the problems resolved. Got to say from the little I've been able to use it so far it's an excellent peripheral

Many thanks all

[t0nyt]

I've decided a white floppy drive looks a bit ridiculous, so will source a black one next week (along with a thumbnail sized USB stick like I use with my other GoTeks)

[XorA]

I've decided a white floppy drive looks a bit ridiculous, so will source a black one next week (along with a thumbnail sized USB stick like I use with my other GoTeks)

IMG_4571.jpeg

Looking smart there, even smarter when you get a black drive!