Spectrum modded / composite question

[Elfish]

After some waiting the vLA82 was back on stock and I ordered one. It finally arrived today after flying around the world.

I sadly couldn't find an original ULA

The result ist different together with the test RAM!
How ever it still doesn't function.
The border seems to be washed white now instead of green.

I'm still on the hunt to get this running. Anyone got more ideas?

[Elfish]

I haven't given up so far.

All caps are replaced with new ones same for transistor TR4 und TR5.
I also removed the upper from their sockets.

No change so far

[1024MAK]

That photo in your last post, it looks to be failing the RAM check in the BASIC ROM. Hence the vertical red lines on a black paper (background).

The horizontal lines may indicate a problem with the address lines.

Did you get a diagnostic card or ROM?

Mark

[Elfish]

I forgot.
Someone let me use a diag card.
It showed, that all RAM is broken. Sounds kinda weird to me, that ALL ICs are dead...

I also replaced the 7805

[1024MAK]

Vsual check all address lines to/from the lower DRAM. If no problems are found, do continuity tests. Print out a copy of the schematic and use a coloured pen to mark each pin of each device as you test.

Then test for shorts.

If none of that finds the problem, try replacing IC3 or IC4.Yours

Mark