Leaky Washing Machine

My friend has a washing machine that we believe leaks only during the fill cycle (puddle on the floor under the machine). I've ruled out a drain leak and all the external hose connections seem okay. I've tilted the washer and removed the bottom cover to check the internal hoses that were visible and they seem okay as well.

What's the best way to troubleshoot this?

Pressure fill switch.

leak

Pull it out, remove the back, fill the machine, and look for the leak.

On mine, the service repairmen removed the front panel. I reckon, it depends on the model. I was told on each service call a different thing, but, I think the general consensus from all involved, was the pressure fill switch. I also, had once, a clog in one of the hoses inside.