I have a water pik wp-20w and do not have a manual, I do not know how to use it

47 Ohms 5%

?I read it from eBay item what replace the circuit board
https://www.ebay.com/itm/163608132963

https://www.arlec.com.au/wp-content/files/MAL606S.pdf

You don't say what rubber item you need for this, so let me guess a little here. You simply often have to get creative for some items that aren't going to be available from the manufacturer anyway. If you have the old one (part), please consider a hardware store (sometimes ACE hardware), OR an automotive parts store such as AutoZone or O'reillys' where you'll find rubber "O" ring kits. If you DON'T have the old part, consider emailing me at [email protected] and perhaps you can describe WHERE it goes on your Waterpik product and maybe I can be of help in that way.

that is what you get with knock off gear
hope they were cheap as they are only good for junk

you must change its batries

To mp3mastr:
I don't have a service manual, but I've owned and used these WP-20W's for 30 years or so and kept them running, so I'll bet I can help you if you'd care to email me at [email protected]
Tell me what's wrong or what you might need.