[Trisquel-users] Trisquel Failing to Boot

[dev]

Today my Trisquel 5.5 system is failing to boot. I suspect it was after  
updates installed last night.

I've attempted to go back through previous kernels to boot with varying  
success; With one of the previous kernels it allowed me to log in, and then  
crashed.

I would suspect a hardware fault but I also have debian installed on the same  
machine (the same HDD, in fact) and that boots and operates correctly.

I wish I could give more information but I can't see the boot text (my  
monitor goes into sleep during boot - a longstanding issue).

How can I force the boot to show text in a known resolution (rather than a  
splash) so I can see what is going on?

Thanks.