Amiga 4000 Dark Grey Screen

[Kepler]

Hi all,

I recently acquired a Rev D (so no dreaded battery leakage) Amiga 4000 board that produces a dark grey screen on startup. The first thing I did was replace the capacitors and cleaned the board. Still a dark grey screen. I am using a know working set of Diagroms.

I have since discovered the following in no particular order:

1. 25MHz clock is present on the CPU.
2. No serial output from Diagrom.
3. U141 appears to be working (Pins 2, 4, 6 & 8 > low to high Pins 10 & 12 > high)
4. AS (pin 125 on the CPU) - no pulsing or waves when checking with my scope.
5. HLT and BGACK both are high. They seem to be high as soon as I power the motherboard

Can anyone provide further direction?