Is the equation "550d + sea water = RIP" correct?

Sorry taking so long to post, but I'm nowhere near home the last few days.

Anyway.. After all this trouble, nothing really changed.

When I insert the battery sometimes it beeps, sometimes not. Sometimes turns on, sometimes not.

Maybe its time to try a new battery? Maybe its eventually the end?

I'll order one battery from ebay so it might take a while for a new post update.

And I'll try to save some money for a new one in the worst case scenario.
Maybe buy a used 550d again or upgrade to a newer model.. I was quite happy with the 550d so I never got in the mood to buy a new one, so any suggestions would be useful (but this is another category-so I'll stick to my problem in this post)..

 

Well... I tried today to turn it on again today, in case any moisture left was gone.
Nothing happened.
Then I got angry and started shaking the camera...
Then it magically turned on...
Everything worked perfect... but only for a while.
So after removing the battery again (which was already fully charged) and reinserting it, nothing happened for one more time.
I left it for a while and then tried again.

Then for the first time, this message came up in the lcd screen: "Change battery pack!" (or sth like this - I dont remember the exact sentence)
So, maybe it's just a battery issue and not a fried circuit after all or maybe I'm just refusing to face reality (again )
I ordered just now a new battery from ebay..
Till then I'm gonna pray!!!

 

Have you tried cleaning the battery contacts, both the battery and in the camera. Sometimes you get a layer of oxidisation on them that is not visible but a wipe with isopropyl can cure the problem.
If you got it going by shaking it then it sounds like connection problem, it may even be one of the circuit board fixing screws are loose or have some corrosion underneath that is preventing a proper ground connection.

 

I really don't know..
I wait for the battery now and see.
For now the only way it starts is by shaking it.
Probably a corrosion problem as you mention, since I doubt anything is loose since I treated my camera all these years like a newborn.
If the problem persists with the new battery, maybe its that. If not, it is a battery problem.
The other thing thats strange, is that the first screen that appears when I turn the camera on is the choice of WB. Like I pressed the WB button. After I press OK, all works fine, except the WB button that is completely unresponsive..
And the screen sometimes switches off.

I recharged the battery again today, and while it should be completely empty (as the camera stated), it got fully charged in about half an hour.. Sooooo it is very probable that the battery itself is off in my opinion..
I'll wait for the new battery and see anyway.

PS. I found my old Zenit today.. After 8 years I'm gonna try analog again!! But first I have to buy some film first! Hope I can make it today!

 

Well.. Sorry it took me so long to post a reply..

The situation is like this..

The battery I ordered never came, so I got a refund. In the meanwhile, the camera started to work again every time, except for the things that went faulty after the "bath".. The UP (WB) button, the microphone (don't have sound in the videos anymore) and another thing that came up lately is that it doesn't keep the date. So everytime I remove the battery to charge it, it prompts me to enter the date.

Other than that, it works fine.

Thats it.

Thank you everybody very much for the support and the solutions given!
Really appreciated it!