I hounded Dell for months and got them to replace I guess 2 or 3 dozens of Optiplex DL270 motherboards and it felt good: forcing them to take the cost for their shoddy work.
The times I had an issue with an HP business laptop I called them and either a technician came to my office and replaced the part (a screen in that case) or they sent a spare after confirming I was capable to change it myself.