Mac SE/30 - White Screen

[MegaImg]

I am trying to fix a Mac SE/30 with Multiple issues:
1. Simasimac display - Fix replacing couple of the Logic IC 2580
2. Horizontal Bars - Fix Damage trace from UE8 to UC6

Now the machine give me a white screen after the boot up bong. No mouse, neither happy mac or error.

 

[MegaImg]

Anyone with any input on this isssue.

 

[bibilit]

Don't remember, but can be related to Bourne Filters

 

[MegaImg]

Don't remember, but can be related to Bourne Filters

So their is couple for the memory, for me that will cause the Simasimac display no the solid white screen. Correct me if I am wrong!

 

[MegaImg]

Just to see if someone have a new Idea! The Behavior, when turning on the power, you can see bright rasters on the monitor, but neither startup bongs nor arrow pointer comes up. Bellow Monitor Image Sample:

The logic board has been recap, All F258 had been replaced and all 4816P-001-220 (RP1,4,5 and 6) to fix semasic pattern . Logicboard has been Sonic Clean and a wire to fix damage trace to the memory IC to fix jail bar issue. I am out of Ideas....

Already try to replace RP2, suggested in another site, no luck....Any pointers

 

[thellmer]

Did you replace those big axial lead capacitors? If you did, check the negative lead on one of those big through-hole axials -C2- where it goes through the hole on the top side of the board. The hole / lead on the top is literally a hair's-width from a trace running next to it and when I redid mine I ended up with what looked like a normal sized tiny dome of solder on the top side of the hole at the base of the lead, but it was just enough to connect to that trace beside it and hold it low which gave me the same symptoms. I had tried everything as I couldn't see the miniature bridge there, thinking that trace might have actually been a designed connection as it was so close and disappeared under the solder dome. But then I decided to start taking things off that I had added, one by one and when I took that cap back off and wicked the hole clean I noticed the lead actually wasn't supposed to connect there. So I carefully put that cap back and made sure no solder appeared on the top side and it booted right up. Then I painted over that tiny nick in the coating with clear nail polish.

 

[MegaImg]

Did you replace those big axial lead capacitors? If you did, check the negative lead on one of those big through-hole axials -C2- where it goes through the hole on the top side of the board. The hole / lead on the top is literally a hair's-width from a trace running next to it and when I redid mine I ended up with what looked like a normal sized tiny dome of solder on the top side of the hole at the base of the lead, but it was just enough to connect to that trace beside it and hold it low which gave me the same symptoms. I had tried everything as I couldn't see the miniature bridge there, thinking that trace might have actually been a designed connection as it was so close and disappeared under the solder dome. But then I decided to start taking things off that I had added, one by one and when I took that cap back off and wicked the hole clean I noticed the lead actually wasn't supposed to connect there. So I carefully put that cap back and made sure no solder appeared on the top side and it booted right up. Then I painted over that tiny nick in the coating with clear nail polish.

The Recap was done by the owner, trying to get it working for him. I removed all of them and put them back. so far i dont see any issues with them. Continuity check has been done in all of them to verify. No issue so far. Anything else!

 

[joshc]

Can you please post some photos of the logicboard?

 

[MegaImg]

Pictures!

 

[joshc]

UE8 looks to have crud under it still. The rest of the board is very clean indeed. Sometimes that whole row of chips needs replacing.

 

[MegaImg]

UE8 looks to have crud under it still. The rest of the board is very clean indeed. Sometimes that whole row of chips needs replacing.

View attachment 59822

Yes, but if I am correct, that will give me video artifacts, not the behavior I am getting....

 

[teemaw]

Hey just throwing in my two cents -- I just experienced this on my board and was able to fix by making sure the ADB (UL11) was good. As I understand it's also possible for bad connections to the SWIM or SCSI to cause this. Might be worth checking those lines if you haven't yet. Best of luck!

 

[MegaImg]

Hey just throwing in my two cents -- I just experienced this on my board and was able to fix by making sure the ADB (UL11) was good. As I understand it's also possible for bad connections to the SWIM or SCSI to cause this. Might be worth checking those lines if you haven't yet. Best of luck!

Thanks! Will check the lines again!