Can one turn on a solid state amp without a load?

I have a Jeff Rowland solid state amp, a model 5 stereo
Amp.which makes a loud thump when I first turn it on.if
It gets shut down and back on before a week it turns on fine. Once it's warmed up it fine.
Yes, when all is okay. Yours sound like the PSU caps are leaky and need replacement.
Thanks for getting back.i have some things to take care of and have not check for a response. I guess it won't hurt to replace them. How many are there?

Only some tube amps have an issue with no load when being turned on.

I believe the Model 5 is dc coupled, you need to monitor (with a meter) the dc offset on the amp.
It could also be the source giving dc offset into the input.

You could try to put shorting rca plugs on the input of the Model 5 to see if it's ok, if so then you may have a problem with the output stage of your pre or source.

Cheers George