Hello Sunrise and thanks for your reply.
I tried both methods:
Bally s5500 and s6000 stay in mains….
Leave you original chips in your MPU board...Turn off the power and pull out the MPU board...
Turn on Dip Sw1 # 8
Put the MPU board back in...
Press and HOLD the PSEUDO COIN and TEST buttons...
You should see CH C followed by CL C...(If you do, then you have what they call "Stay in Mains"
Turn off the power and set the Dip Sw1 # 8 to the off position...
Replace the MPU and power back on...
And with the ram clear EPROM;
For a Complete, Full, or Partial SafeRAMâ„¢ Clear,
turn the machine power OFF.
remove the Main EPROMs from U28 and U43 and replace them with the clear chips.
turn the machine power ON while pressing and holding the PSEUDO COIN and TEST buttons,
When the message CH C displays in WIN PAID, release the PSEUDO COIN and TEST buttons.
The CH C message is followed by CL C.
turn the machine power OFF.
remove the clear chips and replace them by the Main ERPOMs from U28 and U43
turn the machine power ON.
With the 2 methods I have the 2 messages CH C and CL C. and everything seems to be going normally.
But when I put the MAIN chips back in U28 and U43 and I turn on the machine, it goes into error 83F0
When you talk about RAM chips, are you talking about U30 and U45?
I measured the voltage and I have 0.0 v
I did not do it but I will remove the board from its tray and check the welds on the battery holder.