Laney Ironheart IRT-SLS solid state with 2 x tube pre amp

[Arbutt]

Morning all
A bit of a long shot , But i have a Laney Ironheart IRT-SLS solid state with twin 12ax7 pre amp.
Customer was at a gig and was pushing it. then it went pop. Switches on but pulsing. when you removed both or one of the tubes it powers up but no sound. Voltages seem low to tubes around 90v and the LT rails are at 13v-14v
Mr A

[Jazz P Bass]

Schematic attached

[The Dude]

B+ states 400V, then through a couple node/dropping resistors (470 ohm and 2.2k ohm) to the preamp tubes. 90V seems low to me also. If you trace back to main B+, is there 400V there? You may have a node resistor that's out of tolerance, bad cap, etc.

[Arbutt]

Thanks fellas , but this is not a full valve amp. It's solid state with 2 valve pre amp. , I ain't check the output and psu board yet , but I believe it's a class D one

https://www.laney.co.uk/amps/guitar/ironheart/irt-sls