Brett's STE - Repair thread

[rubber_jonnie]

Nice! Test cartridge run yet ? :hide:

No diag cart yet, but I think it may be close by :)

[BrettRogersUK]

I'm feeling like a minor celebration. I traced A1 and found that it should be connected to pin 2 of the DMA. Only it wasn't, so I hooked it up and I now get this:


IMG_20220126_230722.jpg


Which I am going to take as progress since it looks like something is getting to video RAM, something I'd not seen before.

Clearly some work left to be done, but the little red led on my diag cart which shows ROM access is now flickering, a good indicator that ROM access is at least being tried. It was completely dead up until now.

Clearly something is going on and it is trying, so more checking to be done, I'll need to look at A2 next.

I also added some test points near the GST combel and I can see that A1 & A2 are connected all the way from there to the Blitter, the CPU and finally the ROM and A1 to the DMA. I am also seeing address line pulses all the way through now too.

More to do though, @exxos another one for your crash screen archive :)

I'd call that a minor victory. Well done matey, I salute you! There's life in the old girl yet.

Yippee!!!

Regards,

Brett

[derkom]

I'm feeling like a minor celebration. I traced A1 and found that it should be connected to pin 2 of the DMA. Only it wasn't, so I hooked it up and I now get this:

Would be interesting (and possibly educational) to know where exactly the track broke. Have you narrowed that down yet?

[rubber_jonnie]

I'm feeling like a minor celebration. I traced A1 and found that it should be connected to pin 2 of the DMA. Only it wasn't, so I hooked it up and I now get this:

Would be interesting (and possibly educational) to know where exactly the track broke. Have you narrowed that down yet?

Not sure yet tbh, this was a late last night thing so all I did was compare with my working machine and wire it up to see what happened.

Will see if I can figure it out a bit later.

[rubber_jonnie]

I'd call that a minor victory. Well done matey, I salute you! There's life in the old girl yet.

Yippee!!!

Regards,

Brett

Still a way to go I suspect, but I'm definitely more hopeful now.

[Icky]

Good progress @rubber_jonnie, also a good read of the diagnosis and fixes under the capable hands of Dr RJ :)

[JezC]

@rubber_jonnie Go on - you know you want to!

:poke: :hide: :fire: :fire: :fire:

Not you too!!

Just thinking it's another skill to add to your existing set!
Also, can be very useful to help work around faults or shortages. ;)

[rubber_jonnie]

Good progress @rubber_jonnie, also a good read of the diagnosis and fixes under the capable hands of Dr RJ :)

Thank you :)

[rubber_jonnie]

Not you too!!

Just thinking it's another skill to add to your existing set!
Also, can be very useful to help work around faults or shortages. ;)

Very true :)

[rubber_jonnie]

An interesting thing happened just now, I powered the STE on and got a normal black border top and bottom, no stripes.

Unfortunately I didn't get a screenshot of it, and when I turned it back on it was back to the stripey screen.

I was hoping the pixies had been in overnight to fix it, but was sadly disappointed, though it did give me a little more hope :)