Recent content by brrayne

Thank you, that's what it was. There was a nice, big, juicy bit of corrosion under pin 8 of U1950. Cleaned up, replaced and it's booting beautifully. The post can be closed now. This subscription is worth every cent. Many thanks, Bruce

[SOLVED]820-3437 All rails present, fan spins, no display, doesn't boot, CPU not getting hot Hi there, I have a water damaged 820-3437. I replaced a bunch of corroded components, repaired some traces, and I'm getting a fan spin, but no chime, no display, no boot. I have all rails present...

This MacBook is now working perfectly, the only problem is that I didn't do anything else. As I can't get it to play up anymore, it leads me to think that it's a cracked trace or a BGA ball that's intermittently making contact. I could end up losing days trying to find this problem, so I won't...

I spoke too soon, it stopped again. I need to do some more investigating. I'll replace some components around the area of the original corrosion (the probe points between Q7970 and Q7058) and see if anything improves.

Thanks for that Duke. I really thought I'd exhausted all options around the small area of corrosion, but your reply made me go back and have an even closer look. I noticed that the corrosion had got into one of the three tiny drill holes to the top right of Q7058. I used a 0.5mm drill bit to...

Hi there, I have an old 820-2610 that charges, starts, chimes, boots etc. but cuts out after running for a few minutes. Sometimes after one minute, sometimes after ten minutes, but it won't run for much longer than that. It gets the all clear from ASD. I'm aware of the C7771 issue with this...

I ended up replacing the audio port, and the problem is now solved. I think that while I was testing with the board in the case, it was creating some intermittent contact issues, resulting in the problems I was having. While I was testing with the board out, everything worked fine (hence all the...

AUD_IP_PERIPHERAL_DET is 0V without headphones an 3.2V with headphones.

Thanks for the quick reply. All of those resistors are present and correct. The voltages on Q6800 and Q6801 are as follows: No headphones: Q6800 pin 2: 3.2V Q6800 pin 5: 0V Q6801 pin 5: 0V With headphones: Q6800 pin 2: 0V Q6800 pin 5: 3.2V Q6801 pin 5: 3.2V I think this part's working the...

Hi there, I have an 820-2936 and I'm trying to diagnose an issue with the headphone socket. When I got this board, the computer wouldn't switch to the headphones when I plugged them in. After inspecting the board I noticed there were a few components that had been knocked off around the...

I thought that might be the case. Thanks anyway.

Hi there, Strictly speaking this isn't a logic board question, so I apologise if it's off topic. I have an 820-3209 with an LCD that's getting occasional lines and distortions. I've established that it's not the logic board and not the cable, which leaves the LCD. I'm just curious if anyone...

Sorry, yes. All fixed, tested and working perfectly now, thank you. The tip about focusing on VCORE_S0_MCP before PPVCORE_S0_CPU was exactly what I needed. Thanks again, Bruce

Sorry guys, ignore that last comment. The problem was just staring me in the face. C7576 was missing off the board. Knocked off by the looks of it. Thanks again for your help.

Thanks Louis and Duke. Louis, all of the other S0 rails are present. I'm only missing the VCORE rails. Duke, MCPCORES0_EN is there, but there is no voltage on L7560. I don't think there's a short to ground, and the area around U7500 looks pretty tidy. I'm still waiting for my donor board to...