Test 10: 6522 VIA CB1 / Cassette Input Fails but Casette Loads

[Rabs]

Hi,

Test 10: 6522 VIA CB1 / Cassette Input fails on an Oric-1 but a casette loads fine under normal operation.

The interrupt count displayed is 0 and I can see no signal on CB1 or pin 7 of the LM358. I can hear the continuous tone.

This test passes ok on another Oric-1, which rules out my loopback cable.

I think this would suggest that the LM358 is at fault but why would this be if a casette loads under normal operation.

Any suggestions welcome before I replace the LM358.

Thanks
Rabs

[Rabs]

All working, replaced the LM358.

There was a dodgy solder joint but reflowing this did not help.

20251024_153422.jpg

Here is the dodgy one

aeb58141-c766-4cd6-af3e-a5d5904bed4a.jpg

And the new one.

dc8f74a0-651e-42ed-959d-88b7fd0f2edd.jpg

[iss]

Welcome here, @Rabs!
This is rare fault but not impossible. Well done!

[Rabs]

Thanks, enjoying my return to the Oric-1. Originally I had a ZX Specturm when I was a kid but returned it after a few weeks because it was faulty and got an Oric-1 instead. The rest is history as they say

[iss]

Nice story.
Else, to get faster and proper answer it's always good to include some pictures.
For your case it was important to mention what "Test 10" means i.e. from Mike Brown's (aka @mikeb) Diagnostic ROM.

[Rabs]

Good point and I did think I should clarify that this was from Mike Brown's diag tests.

Will do next time. Thanks for the tips.

[Chema]

Nice repair! Well done.