820-2330-A No chime or display

[pcfriends]

This board like 3 years ago I send it to repair to a ebay guy , he send it back working and die again , I send it back , he send it back working and die again , I send it back , he send it back working and die again , my warranty on this board expires , and I have to buy anotherboard for my customer back then.

I save it , and now recently I start troubleshooting this board I order a donorboard and all that shit , and when I when to the power rails I find out that PP1V2R1V05_S5 was not there I replace u7750 and c7771 and I got back that rail to work

After that machine power on, fan spin, but I cant hear any chime and I have no display I did the microscope light trick behind the apple logo to check for display and nothing.

I when and check the next rails: PPVCORE_S0_CPU That read around .9v almost 1v


=PPVCORE_S0_MCP= 1v

I did check some other rails but i want to hear what the people who knows more than me think i should be checking on this one. thank you!

 

[dukefawks]

Original problem was probably just C7771. Ebay idiot reflowed the MCP and messed it up. Replace MCP, but this is soooo old.....

 

[pcfriends]

thank you for your answer , i have no equipment or skills to replace a MCP yet i guess i will just send the board back where it was saved , and yes i work on many olderboards i figure that will be cheaper to learn with older boards than with new ones.

 

[larossmann]

duke's psychic powers are correct here.

replacing an MCP79 is easy as cake. Finding one that isn't dead.. good luck with that one.