So after deep clean and keyboard clean checking what to do next built up a list since this Christmas it will be 40 year old components in there. So, recapping on the list first.
Reading others was changing the GAL upgrade to fix issues with few games due to issues with the HAL10H8 memory fault. This has been preprogrammed with Unrainer for Spectrum 128.
Another on the list is changing this oversized heatsink and L78S05 regulator.
And replacing it with a TSR 2-2450.
Another replacement Alan Sugers boys followed the silkscreen on installing the 2N3904 Transistors, but they were back to front for the transistors used and needed to be replaced. These are TR4, TR5, TR7 on the main pcb.
TR4 is part of the composite video circuitry, TR5 is responsible for generating the RGB vertical sync, and TR7 is responsible for generating the ULA IOREQ signal, so having all of them reversed causes serious video problems. Replacing these should improve the composite out.
The last one just because I’m there, let’s see if they do anything. So 1st A 15uH inductor & 82pf Capacitor for Spectrum 128 and +2 Video mod. Which is related to removing Blue/Yellow ghosting from the +2’s Video Output.
So quick hit I’ve replaced the regulator
Quick easy desolder with braid below the pins with a bit of flux.
All of these have been ordered from http://retroleum.co.uk/
