Philips does not provide clear instructions pertaining to the indicator lights on your shaver. The cleaning indicator is a little picture of a faucet o the front of the shaver. When this indicator is illuminated, you need to physically remove each of the heads from the shaver and seperate the cutters from the combs to thoroughly clean them. Once you have cleaned them, the Philips user manual says that the light may not go off and you should then ignore it in this case.
The shaver has a seperate light that is a small picture of the 3 heads of the shaver. When lit, this indicator means that you should change the heads. Again, the Philips user manual instructs the user to ignore this light if it does not go off.

If needed, new heads can be purchased at shaveroutlet.com. See link below.
http://shaveroutlet.com/norelco-philips-hq177-cool-skin-replacement-heads-p-245.html

If in the US, you can call Philips customer service for more details at
1-800-243-3050

You can also view the user manual for your model with the link below.

http://download.p4c.philips.com/files/7/7775x_43/7775x_43_dfu_aen.pdf