2006 Mac mini Possible fix for no power to logic board

[aurora72]

Yes, it would but the other concern would be the vias - the round holes which are tracks that travel through the board making connections within the board and on the other side.

It's a lot of work and will probably require removing, cleaning, checking the ATI chip on the other side of the board.

However, if you have someone wiling to do it for a small fee and you know they are capable of this work, then yes, it might fix the missing 16MB VRAM (the G4 1.25Ghz model has 32MB VRAM) and the video output issue.

After 7 months, I've finally found the opportunity to remove the 16MB VRAM chip and its tiny components on the other side of the board. I didn't hand it to a repairman. I've removed the related components and cleaned the solder residues using solder wick and isopropyl alcohol. I took precaution not to heat the plastic LED connector and the BIOS battery holder. It looks quite clean now:

However the video output is still the same scrambled. Actually, nothing has changed after I removed the chip and the components. I'm still able to access it over the VNC connection though. When I leave it running for hours it doesn't get too hot. Everything works normal except video output.

I think I have one more option: Reheating the ATI chip with the heat gun so that any possible disconnected pins reconnect and the corrosions are eliminated if there are any. Is it advisable? What's the best thing to do here?

 

[aurora72]

The other week I bought a non-working Mac mini 1.5 SOLO for $12 w.o. power adapter. I'm planning to repair it. The MoBo looks clean. When I power it, CPU fan immediately spins at maximum speed (5500 RPM) and no power comes to MoBo. Pressing the power has no effect. I've asked ChatGPT by sending the image below which parts to check, it said,

The critical components (to check) are around the SMC chip

1. SMC VCC decoupling capacitors
   • Small ceramic caps directly adjacent to SMC pins
   • Shorted MLCC here is VERY common
2. SMC LDO regulator
   • Usually a small SOT-23-5 or MSOP-8 nearby
   • Supplies ~3.3 V or ~1.8 V to the SMC
3. Reset / power-good resistors
   • Tiny resistor network next to the SMC
   • If pulled low → SMC never starts
4. SST-25VF016B SPI flash
   • Must receive power and clock
   • Short here can kill SMC rail

I just couldn't identify the SMC chip, ChatGPT is talking about. Is there even such a chip on this MoBo? If yes which parts should be checked? Someone please help. For good measure I'm sending the front view of the MoBo too. Are there any parts to check there too?