I used to use Marshall until i bought a Spider II 75 head, I promoted that to a spider III 150 combo, then to a HD100 ... I now have a Spider Valve 112 combo MK1 that has served me well until now!!
My volume started to drop randomly on channels, it would return simply by switching to another channel and then back again. This lead me to believe that I had a software issue... insted of performing a factory re set i did this..
1) I held tap and powered on.
2) I messed around with the dials, the channel lights for A,B,C,D, Effects and TAP switch on and off as i mess with the dials l, the lcd display went up and down as i mess with the dials.
3) I switched the amp off.
4) I switched it on again
5) The amp no longer allows me to select any amp models.
6) Hold 'A' and power up, factory re-set..
7) Still the same issue cannot select any amp models..
Oh Lord WHAT HAVE I DONE... THIS IS MY GIG AMP AAARGH, HELP AN IDIOT PLEASE!!!