820-3437 no led

[arnonabuurs]

This 820-3437 has PP3V42_G3H and G3H, SYS ONEWIRE = 3.4 and BC-ACOK also present. I get how the one wire works for Pro but for air seems to work different? I remember that I saw a vid from Lewis about it but i cant find it. If you can point me in the right direction I can check it first myself. Tips also welcome as customer needs to leave Thailand tomorrow and its 12AM so I have only one night to get it fixed

 

[dukefawks]

Does the machine power on? What is PPBUS voltage?

 

[arnonabuurs]

No there is no fan and no LED. PPBUS 8.22v

 

[dukefawks]

PPBUS 8.2V means SMC is not running. SMC_RESET_L present? Corrosion around SMC?

 

[arnonabuurs]

There was corrosion around SMC indeed, I have tried to reflow but that didnt work should i try to reball it instead?

 

[arghhh]

No, you should find out if SMC_RESET_L is high or low.

 

[dukefawks]

If SMC_RESET is high then it is probably crap under it or it is dead.

 

[arnonabuurs]

I have to give up on it as the customer is leaving back home tonight on to the next one thanks for the help learned a lot again! One question, can you buy SMC chip from china pre-balled and use those or do they need to be from the board itself? I bought a lot of IC from China (non SMC) and so far they have always worked fine, most where power IC though.

 

[dukefawks]

SMC chip has firmware and needs to come from an identical donor board.

 

[arnonabuurs]

OK now I have 1 more month to fix this issue . I do have a donor board but I do not have the reballing stencil do you happen know where i can get those, maybe somewhere of Ebay?

 

[dukefawks]

https://www.rossmanngroup.com/boards/forum/tools/7124-smc-stencil-recommendations