How to hard reset of a Samsung Galaxy GT-I9000 which I cannot put in recovery mode? I don't have much hope. Here is what's happening

Galaxy S GT-I9000 keeps crashing at startup : 
com.sec.android.provider.logprovider crashes 
and other ones android.process.acore 
 
So I cannot reach any settings to disable some system settings like Settings/Privacy 
So I cannot connect usb (it's never seen by my PC) 
 
And a very good joke : it cannot be put in recovery mode !
http://forum.xda-developers.com/wiki/Samsung_Galaxy_S_Series#Recovery_Mode 
Does nothing 

Somebody have notices some i9000 in this case :
http://www.addictivetips.com/mobile/fix-3-button-combo-download-recovery-mode-in-samsung-galaxy-s-gt-i9000/
Too bad I can't do this : "Now plug the USB cable into the phone. Start a new command prompt window and navigate to the folder/directory where you have installed ADB."
As my phone is not able to make the usb work ! 

So is there a way to reset the phone the hard way ? 
I mean by opening it and erasing the memory to revert to an empty phone fully ... 

PS : I cannot tell the android installed on this phone. It's not mine. All I know is that it's pretty old and that it's a custom "Orange" ROM.
Did you try this:


Turn the power off. If your Samsung Galaxy S is frozen, pull the battery out and reinsert it
Hold the Volume Down button
Press and release the Power button
You are now presented with a menu that allows for Fastbook, Recovery, Clear Storage, and Simlock
Select Clear Storage by pressing the Volume Down button
Press and release the Power button
Now simply confirm your decision: Volume Up for YES and Volume Down for NO


(Source: KnowYourCell.Com -- the first hit on a little Google Search)



UPDATE: Alternative approaches are listed at Hard-Reset.COM, e.g.:


charge your battery fully before doing a hard reset
PRESS AND HOLD VOLUME UP + Home Button (or VOLUME UP + DOWN)
Keep pressing these 2 buttons + press Power button for 2-3 Seconds
Release only power button, but KEEP pressing Volume up + Home Buttons (or VOL UP + DOWN)




You also might check with the following question here: SGS doesn't go to download, recovery mode nor does it connect via USB after installing a battery MOD