Hello I have a Xerox WC 7855, But Recently the printer doesn't wake up from sleep. No button Work (even the power button) or sending anything from the Computer works. I have to completely turn-off printer from power socket and then turn it back on to use it again.
I tried to re-install firmware via altboot with FORCED_UPGRADE still no help.
I would recommend moving up from the 072 level firmware. When you tried to use the 073-level firmware, did you apply the pre-upgrade patch that's needed? Failing to apply the patch before moving to 073 can cause a number of issues. Anytime I come across a machine that is having stability issues running 072 firmware, the first thing I do is bring the firmware (relatively) current. If the original problem is not hardware-driven, it fixes it.
I would actually recommend working directly with a local Xerox agent or service tech to do a forced Altboot for you in person to the below linked level. I've tested it on the machines at my agency's offices and have used it out in the field since January with no major issues. It's from November 2021 and there are quite a large number of fixes introduced since the 073 level you mentioned was released in 2015.
A forced Altboot will wipe the machine's current configuration so make sure you have the current setup well documented so it can be set back up again, or make sure your IT group is aware of this if that's not your responsibility.
Sir, First of all, Thanks for your valuable time and reply. As I stated I tried v73 level firmware (after I change my hard disk a few months ago). But sadly my print comes out noticeably light and low quality. Many of my customers started complaining. When I ask my local Xerox Service person about my issue he told me that v73 firmware print quality is light and low (to save toner consumption I guess) and he suggested that I revert back to v72 which I did. As per v75, I don't think you can altboot v75 software which needs to be upgraded from the browser. Anyway, I have no issue to upgrade to v73 if there are ways to solve print quality issues, sadly I didn't find any.