SE/30 Logic Board Question

[AichEss]

Trying to figure out a "new" logic board in an otherwise proven SE/30 computer.

Known good ROM SIMM

Known good all RAM modules

Known good floppy & hard disk drives (known good Disk Tools or system software)

Starts with no chime but with a good image of the "happy Mac" on the CRT, goes to the "Welcome to Macintosh" screen but doesn't go any further. Just after the welcome screen appears either the floppy or the hard drive quits reading.

The "Repair Macintosh SE/30" site doesn't have this particular problem. I hope its just dust somewhere.

AichEss

 

[phreakout]

Starts with no chime but with a good image of the "happy Mac" on the CRT

Okay, this could be normal, but could also mean Simasimac. Verify that the volume is turned up, say about 3 or higher, and if you get audio, it probably may not need a recap. Although, eventually, you will need to consider having it done anyway.

goes to the "Welcome to Macintosh" screen but doesn't go any further. Just after the welcome screen appears either the floppy or the hard drive quits reading.

It's probably a corrupt System startup or a bad file extension. Try running Disk First Aid to rule out anything wrong with the disks. Also, try booting up with the Shift key held down to bypass the System Extensions, except for those required for booting. And last but not least, try booting with another known good startup disk. It could be that there are major problems with that drive or disk.

I won't add in possible SCSI and/or floppy disk controller chip fail until other things are tried out. A bad SCSI controller chip (53C80 @ UI12) would show an arrow cursor in the left upper corner but no smile mac and no startup.

Try all this and report back with results.

73s de Phreakout. :rambo:

 

[AichEss]

Hi Joe

Seems like you are coming to my rescue again.

Several Disk Tools floppy disks and the hard drive are perfect with the logic board you recapped for me in either of two SE/30 chassis. With any of these the board in question stops at the same place in both chassis.

A further observation - the arrow cursor does not appear in the upper left hand corner.

AichEss

 

[phreakout]

Okay, so the freezing up happens before extensions are loaded and the mouse cursor is missing. The cursor does disappear from time to time during startup and that's normal. If the cursor were to disappear, all you see is a bright raster (light grey background) and no startup would indicate to me that RP2 (Bourns Network filter) on the logic board needs replacing. But let's no assume that quite yet.

If we rule that out, along with a bad UI12, then logically it leaves the OS at fault. This would mean checking to see that the disks are still good and that none of the files are corrupted; especially when you've got freezing just before extensions are loading.

Let me think on this a bit more and get back to you. I've got to go on a quick one day road trip and be back later tonight. I'll look through the schematics on the SE/30 and also study some of the troubleshooting resources I've got.

Hang in there!

73s de Phreakout. :rambo:

 

[AichEss]

OK.

A bit more experimentation and another observation (but no real progress).

With no keyboard, just a mouse, the startup goes all the way to the normal screen with the menu bar and hard drive and Trash icons. However, the screen is locked up and the mouse will not move the cursor. The same result with several keyboards and mice which work just fine with any other ADB-capable computer I have. I thought the ADB drivers were in ROM.

I don't know if it makes any difference for the troubleshooting but this logic board has a socket-mount CPU and the mount looks to be original. I didn't know such an arrangement existed.

AichEss

 

[WhoaMan]

When you boot it up with just the mouse connected... and it shows the main (but frozen) desktop... does the time and date appear to be correct? if not, is it always the same date and time when it reaches this point?

If you have no floppy in the drive and disconnect the hard drive, do you get the floppy icon with the question mark? If so, does it blink?

I assume it is not switching between the main and alternate video buffers and that is why it appears the screen is frozen and has no cursor... and since you mentioned the ADB symptoms as well... i would check around UK11 (Via 1) and UK4.

If you happen to have a digital multimeter with a frequency counter or a standalone frequency counter.. i could check pins 1 and 2 on the UK1 (should be 1herz and ~32kiloherz respectively). Also check for +3 between pins 8 (+) and 4 (-)

 

[AichEss]

Hi whoaMan

When you boot it up with just the mouse connected... and it shows the main (but frozen) desktop... does the time and date appear to be correct? if not, is it always the same date and time when it reaches this point?

The time and date don't appear. The HD has SS 7.0.1 and I don't think it has a menubar clock. During the startup the little "wrist watch" icon appears and it does maybe two clicks - that's about all of the action.

If you have no floppy in the drive and disconnect the hard drive, do you get the floppy icon with the question mark? If so, does it blink?

The floppy icon shows and the question mark blinks e_v_e_r s_o s_l_o_w_l_y.

As for your suggestions, I am a total naif around PCBs. Hell, I can't even bring myself to take a shower with one to clean it! There is a bit of "cap stuff" around the caps that I gently cleaned a bit and it doesn't look like it ate up anything but ... Is UK1 the line of 15 tabs along the edge of the board?

AichEss

 

[WhoaMan]

Cap stuff.... as in the capacitors were leaking? If they have leaked at all, you will want to replace them before going any further in your troubleshooting as it will make the system unstable, and to be honest, could be creating all of your issues