Macintosh IIci No display

[jmacz]

@ExplorerZ a couple thoughts.

I know there was an earlier discussion on the ROM select jumper. Your latest picture doesn't have a jumper installed, and I don't see a ROM installed either. Maybe you had it off for the picture? Not sure, but again to clarify, the W1 Rom Select jumper must have a jumper on it if you're going to leave the ROM slot empty. So to use the motherboard soldered ROM, you need to have a jumper on W1. If you want to use your own ROM chip in the ROM slot, then you remove the jumper. If you already know this then please ignore. But just clarifying. I also am not sure I fully understand what broke on the jumper last time (was it the actual pins on the motherboard or the jumper itself?) but if that area is damaged, you may want to take another look because that might result in no activity on startup.

The area around the BT ramdac (where some capacity work was done) looks a bit wonky - I assume the leads aren't touching anything they shouldn't be?

Also the sound chips (UB2 and UB3) play a role in startup. The legs on UB3 seem a little wonky. Might want to double check those that they are fully connected and all of those pins buzz out properly to where they should go.

I can't tell if it's just the picture, but the chips in the startup circuit (UD13 in particular but also UE13 and possibly UB13) don't look very healthy? Might also want to check all those legs are connected and there are no broken traces there. Note on one of my IIci boards, I actually ended up having to replace all three of them as they were totally destroyed by the leaking C10, C11, C12, C13 capacitors.

 

[ExplorerZ]

@ExplorerZ a couple thoughts.

I know there was an earlier discussion on the ROM select jumper. Your latest picture doesn't have a jumper installed, and I don't see a ROM installed either. Maybe you had it off for the picture? Not sure, but again to clarify, the W1 Rom Select jumper must have a jumper on it if you're going to leave the ROM slot empty. So to use the motherboard soldered ROM, you need to have a jumper on W1. If you want to use your own ROM chip in the ROM slot, then you remove the jumper. If you already know this then please ignore. But just clarifying. I also am not sure I fully understand what broke on the jumper last time (was it the actual pins on the motherboard or the jumper itself?) but if that area is damaged, you may want to take another look because that might result in no activity on startup.

The area around the BT ramdac (where some capacity work was done) looks a bit wonky - I assume the leads aren't touching anything they shouldn't be?

Also the sound chips (UB2 and UB3) play a role in startup. The legs on UB3 seem a little wonky. Might want to double check those that they are fully connected and all of those pins buzz out properly to where they should go.

I can't tell if it's just the picture, but the chips in the startup circuit (UD13 in particular but also UE13 and possibly UB13) don't look very healthy? Might also want to check all those legs are connected and there are no broken traces there. Note on one of my IIci boards, I actually ended up having to replace all three of them as they were totally destroyed by the leaking C10, C11, C12, C13 capacitors.

Will take a look at the chips and caps. I have been using a rom simm, it’s just not in the photo. The Jumper itself broke.

 

[ExplorerZ]

Replaced some SMD caps and tried to clean up 2 chips. It now powers on with no display or chime even with the rom simm. Pretty sure I messed up the right sound chip.

 

[imactheknife]

Replaced some SMD caps and tried to clean up 2 chips. It now powers on with no display or chime even with the rom simm. Pretty sure I messed up the right sound chip.
View attachment 69883View attachment 69884View attachment 69886View attachment 69885View attachment 69887

Sound chip needs to be set properly and will affect startup and chime of course. Check continuity and if you need to touch up legs just a little flux and a little solder on end of iron and touch the leg and pad etc. the legs look like they aren’t touching the pads.

 

[jmacz]

If I remember correctly, almost all the pins on those sound chips had nearby vias you could test against for proper adhesion and continuity. I concur with @imactheknife that the legs don't look they are touching the pads.

 

[ExplorerZ]

Thank you for all the advice, I will do what you said In messages and what imactheknife said.
PS: After leaving the IIci on for a while the screen displayed gray.

 

[ExplorerZ]

Right sound chip legs are touching the pads (tested with traces), but when i was touching each leg of the chip to each other with the multimeter 3 of them were getting a continuity of 600 to 1000. Zoomed in 12x but I cant see any solder that could be bridging it. The multimeter didn't beep like it usually does when I was touching the legs with the multimeter, so maybe its not bridged. Will update later after I touch up the sound chip and check UD13 and the ones near it.

Sound chip needs to be set properly and will affect startup and chime of course. Check continuity and if you need to touch up legs just a little flux and a little solder on end of iron and touch the leg and pad etc. the legs look like they aren’t touching the pads.