Icky - Progress

[exxos]

OK - I found some bad soldering on the RP6. I cleaned it up and now I am getting bombs but the screen is still all over the place. Let me attach a video

OK.. might be idea to measure resistance on each CPU pin and make sure you read something to VCC.. (IE 2.2K)

If your using Csync on your cable then the voltage may be to low... https://www.exxosforum.co.uk/forum/viewt ... 204#p10067

[Icky]

OK.. might be idea to measure resistance on each CPU pin and make sure you read something to VCC.. (IE 2.2K)

If your using Csync on your cable then the voltage may be to low... https://www.exxosforum.co.uk/forum/viewt ... 204#p10067

Thanks Exxos for all the help today. I will take a look at these suggestions tomorrow it has been a long day.

Here is the video of the board being reset and briefly you can see the bombs

[exxos]

Cool! So we need to get your video stable more than anything next... You might even be able to try the diagnostic cart in the thing.. I mean even if you get a red screen it will give a clue how far down the ROM its getting..

Indeed a long day, we went through a lot today! :cheers:

[Icky]

Cool! So we need to get your video stable more than anything next... You might even be able to try the diagnostic cart in the thing.. I mean even if you get a red screen it will give a clue how far down the ROM its getting..

Indeed a long day, we went through a lot today! :cheers:

Yes great tag team today between you, me and Forgottenmyname and help along the way from a few others.

[exxos]

Not going to be around much today.. but some thoughts..

Bridge over R127.. if your video lead as like 330R like in the diagram posted earlier, then the value is likely to high.

Also check V&H sync voltages and waveforms, and also check CSYNC voltages vs a working ST...

You could try swapping the BC337 for a 2N3904 from the donor board.

[Icky]

Not going to be around much today.. but some thoughts..

Bridge over R127.. if your video lead as like 330R like in the diagram posted earlier, then the value is likely to high.

Also check V&H sync voltages and waveforms, and also check CSYNC voltages vs a working ST...

You could try swapping the BC337 for a 2N3904 from the donor board.

Thanks Exxos - I too am not around much either. I will take a look at these later tonight.

[Icky]

Just had a look at my scart cable and the csync from ST goes straight to the composite on the scart. It’s a bit of a simplistic cable only the rgb resistors.

Am going to update the cable a bit

[PeteW]

Sorry I've been lurking and watching these build threads with interest :)

Does the cable work with a 'real' ST and if so, what's the difference in csync signal between the 2?

Ignore me if I'm talking rubbish 😁

[terriblefire]

How are things going.. do we have a current list of required patches? Is there anything I can add to DiagROM to help out?

I've not had a chance to start my build yet.. but i have been clearing the decks so i can start. Is it worth it with this revision?

[Icky]

Sorry I've been lurking and watching these build threads with interest :)

Does the cable work with a 'real' ST and if so, what's the difference in csync signal between the 2?

Ignore me if I'm talking rubbish 😁

EDIT: Hi PeteW - sorry am phased tonight. Happy for the suggestions.

Yes the cable currently works with STM and MegaSTE you can see it on my STM here https://www.exxosforum.co.uk/forum/viewt ... f=18&t=700

Haven't had time to measure between the two - today has run away with me.