Flooded Circuit Board Repairs

[Sean Ram]

Hello,

we have about 300 analog cordless telephones that have everything working on them except the ring when calling the phone. I am thinking it is a small component that needs to be replaced or it is corrosion that is blocking the connection. I am hoping someone can help me figure out where on this phone the defect is coming from. We tested the ringer and it works but when you call the phone it wont ring. All other features work just fine. If it is a component you see that needs to be replaced let me know a site it can be purchased if known. See photos
Thanks so much. https://photos.google.com/share/AF1...?key=Nm5iaHQtbEFJbDlYS250M1AxLWdPeXpZRkFscm1n

https://photos.google.com/share/AF1...?key=OC1NdTdhX1ZIc0tmbDVLN0pJdWFUUVpSaU5sLVFn

https://photos.google.com/share/AF1...?key=cy16MlFCbGh6ZXpoYTI1VTdTSEFSMmlhT1dzbVp3

 

[JMW]

As requested on another forum. What country and what are the local ringer specs?

 

[Sean Ram]

USA. I think I narrowed it down to the little metal boxes on the right side. They have little pages like a metallic book and when glueing together and scraping the top it rings intermittently. Not sure what this is called or where to buy them

 

[Nanren888]

No idea about the US phone system, but some places have had changes over time between 2-wire and 3-wire systems, which affect how the ringer signal arrives. I imagine if a phone expected the ring signal in one place and it arrived elsewhere it might not ring. May I ask whether this has been checked out?
Sorry if this is nothing more than a distraction.

Another direction: ringer specs have changed over time, or at least the ringer voltage. If the system you are trying on has a low ringer voltage, but the ring detector is expecting a higher voltage, might not ring.
.
My theme is of course, are you sure that it they are faulty? Seems a little strange that all fail the same way.