Mac SE - Was working, now black screen and no chime

[BlueBoy]

I recently acquired a used Macintosh SE, 4MB RAM, 2x 800k drives + 160MB IBM SCSI Drive (internal and Apple Labeled IIRC). It came with some nice extras but the floppy drives weren't working properly.

Wife and I disassembled the SE, discovered we actually had a 1.4 MB floppy drive (just needed cleaning & lube) and an 800k floppy drive with one of the heads ripped off. The hard disk was just mounted by one screw and the two floppy drives were both in a bottom-style cage (1 of which was mangled.)

Well I wanted it fixed up, so we removed the bad floppy, lubed the other, replaced the logic board with a FDHD version and added the correct upper drive cage. I even 3D-printed a slot cover for the upper bay because I couldn't find one online.

The SE worked great; it powered on and booted from hard disk, floppy or external SCSI drives just fine. Then we had to move everything out of our condo temporarily and the movers packed it up (and several other computers) and hauled it away.

We finally moved back in and unpacked the computers. All of them work (so far) except the Mac SE. Flipping the power switch results in a black screen and no startup bong/chime however the fan and hard disk do spin up. It doesn't seem to boot though.

I've checked the Dead Mac Scrolls, the SimasiMac page as well as skimmed the classic mac repair guide here. Nothing seems to fit my particular symptoms. There is no crackling sound, or any other for that matter besides the fan and hard disk. There are no strange odors (yet, at least.)

Could it just be a loose power connector to the logic board? Hopefully we won't have to repair the logic board. Wife and I will open it tonight to check on stuff (I am disabled such that it would be difficult for me to open the machine by myself, or I would).

Any ideas, oh wise and way more experienced liberators? Thanks in advance...

 

[BlueBoy]

OK, so update!

We opened the SE, reseated cables attached to the logic board and made sure the ram was fully seated and it booted right up.

Huzzah!

 

[just.in.time]

Congrats

 

[Fogtripper]

Just bought an SE/30 that had a working screen before the sale, but same systems as above upon arrival. The seller's son said he used to be able to get the screen to come on by turning the mac on and off a few times (which I really did not want to do on my end). No bong, and HD spins up, but no screen. Really hoping it is as easy a fix as BlueBoy's.

 

[SlateBlue]

Has the logic board been recapped?

 

[Fogtripper]

If that question was directed at me, not that I currently know of. I need to crack it open. Had intended to send to maccaps in any event.

 

[SlateBlue]

Yes, sorry, my response was directed toward you. I'd start with a recap and then go from there.

 

[flashedbios2012]

Another thing that may help is washing the board.  A recap still needs to be done, but if you wash the board, and things get better, you at least know you need to recap.  This worked on a Classic I had once.

 

[bibilit]

The SE has not the same type of capacitors the Classic is plagged with, no need to wash the board...

 

[Fogtripper]

Update on my dead screen issue:

Got a long-enough T-15 in today and cracked the SE/30 open. Since it had no video, I let it sit for a few days after pulling plug before shutting it off. Read somewhere that this may discharge it a bit, but was speaking of functioning screen so...

In any event I managed to crack it open, unplug the HD and such from the MB. I blew off the dust from the MB with compressed air. probably need to google how to get the purple PC eating battery out. Slid the HD out and was pleasantly suprised to see the 240mb Quantum in there. No RAM upgrade, but I plan to max it out with OWC after I get the BMOW ROMinator in.

So I was peering around the now gutted innards, and I think I figured out what the screen issue might be:

The thingie that is at the end of the tube at the end of the screeny... is completely unplugged from it's board. Fingers are crossed.

MB looks decent from my aging miopic eyes, and will be sent on to maccaps presently. The other boards are still dusty.

So there is the trip report so far.

*happy dance*

 

[jsarchibald]

I bought an SE/30 recently that was non-working.  Pulled it apart, and all the cables were disconnected.  Reconnected them all and it made all the right noises, but the screen was blank.  After much head scratching, I noticed that the yoke was not attached to the crt, and after straightening a few bent pins and reconnecting, it booted right up, and ran perfectly.  I am now left wondering why someone felt the need to play with it in the first place, as it all worked well apart from someone meddling with the internals.  Go figure!