Newbie could use some help with half-dead SE/30

[Tonebender]

First post here ... hope you don't mind me asking for some help.

I was lucky to get my hands on an SE/30 for free last week, but it won't boot. The fan runs, and it starts with the familiar bing in the speaker, but the screen is dead ('cept for some glow in the tube in the back) and there is no sound whatsoever from the floppy or hdd. It has a NIC which blinks green once when I switch the power on and once more when I turn the computer off. That's it.

Any suggestions as to where I should start diagnosing this thing?

I've gone so far as to open the cabinet and looked around. The thing is suprisingly dusty and dirty inside, but there are no specific visual give-aways. No burn marks, no bulging caps, no obvious corrosion, etc.

I'm a newbie when it comes to Macs but have plenty of experience with the soldering iron and poking around in high voltage appliances (such as tube amplifiers).

Thanks for any tips!

 

[techknight]

This is really starting to grow a beard. 

Recapped? 

 

[Elfen]

Grow a beard and its female on top of that! LOL!

Tonebender - use your nose, is there a Fish Smell? A Fish Smell, no matter how slight, would indicate that the caps on the logic board has leaked.  SE\30 Macs have a bad reputation of having their capacitors' seal break down and leak cap-goo everywhere, causing corrosion on a microscopic scale. This requires that the board be washed in an Ammonia & Distilled Water bath to neutralize the cap-goo acid, and then scrape it down with acetone with a tooth brush and rinse with high  proof Isopropyl Alcohol before getting the board recapped.

You can recap the board your self or pay somebody to do it. Forum member Uniserver has an excellent reputation of recapping Mac Logic boards, and brought mine from the brink  death - literally! I recommend him. The caps are Surface Mounted so that requires something different in term of soldering that you may have done with Tube Amps.

If you recap the board yourself, when you remove the cap from the logic board, brush the area with a toothbrush and acetone to remove any cap-goo that remained even after you washed it. And then wipe it down with a paper towel soaked alcohol before soldering the replacement cap. Even then, this is 50% of the job because the SE\30 is still dead and requires more work in tracking down broken traces from the cap-goo with a multi-meter and soldering a wire in its place to fix it.

If you send the Logic board to be recapped and repaired, focus your attention on the Analog Board. Check for burnt components, broken solder joints and fix as necessary. Do not reheat and reflow broken solder joints! Desolder it to remove all the old solder, and resolder with fresh flux and solder. Reheating a solder joint only fixes it temporarily and you will have to fix it again in a couple of months when it breaks again. Resoldering it with fresh solder will make the repair last for years. Get the books "Dead Mac Scrolls" and "SE Upgrade and Repair Secrets," they will be helpful in future Mac SE\30 repairs.

Question: Have you turned it on and adjusted the Brightness on it? There is a knob on the left bottom of the front of the machine to adjust the brightness. Many people do not realize that it is there and turn on their Mac and the screen is dark and assume that something is wrong.

EDIT: The Dust and Dirt may have kept the cap-goo from spreading, so you may have lucked out in that. But still, the logic board needs recapping in the very least.

 

[Bunsen]

I don't know if the SE/30 is one of the machines prone to this or not, but sometimes replacing the onboard battery will allow you to boot.

The quick test for that is to remove the battery (it should be on a jumper & leads) and then try to boot.  If that doesn't work, leave it powered up for a half hour or so and then very quickly switch it off and on again.

 

[uniserver]

haven't met a se/30 mb yet that didn't massively need caps.

Charles

 

[bibilit]

No battery required for a SE/30, check PSU outputs first, clean the board and let us informed.

 

[Tonebender]

Thanks for the quick replies, and Elfen - thanks for the thourough reply. I suppose I should start with what bibilit says: check the PSU outputs to make sure there's power there at all.

I did adjust the brightness control now, and noticed there is a faint vertical line straight through the middle (although not continuous) of the otherwise black screen. Does this mean anything?

 

[CC_333]

It means you probably have a cracked solder joint somewhere on the analog board. In particular, it could be the CRT deflection yoke connector (J1 on a 128k-Plus, or P1 on the SE and SE/30). If you have the nerve to operate the machine with the rear bucket off, try gently wiggling this connector (with insulated pliers) and observing the CRT for any changes (to confirm if it's the problem).

You can also reference the very useful Larry Pina book, Macintosh Repair and Upgrade Secrets. An online version can be found at MacCaps.com, but I suggest also buying the print version if you can, as it's a very handy book to have around in a physical form.

c

 

[bibilit]

from Biwa site:

2. A Bright Vertical Line in the Black Monitor

Symptoms
When starting up Mac SE/30, only a bright vertical line is shown in the black monitor. The width of the vertical line is approximately 5 mm. During start-up, you can see moving raster patterns in the vertical line. You can hear spinning sound of the hard disk drive also. The hard drive seems to be OK, and the vertical line seems to show the startup picture though very compressed to 5mm in width. 

Diagnosis
The horizontal sweep circuit on the analog board is broken.
Ageing and/or cracks in the soldering of either (1) P1 connector, (2) C15 electrolytic capacitor (3.9uF, 35V, 85degree C, HighFrequency, NonPolar) or (3) L2 variable inductor on the analog board is the major cause of the problem.
The most frequent cause is soldering failure of the P1 connector due to ageing and/or cracks. In this case, you will see the burnt and/or charred P1 connector.

Solutions
The first thing to do is to check the connector, capacitor or the inductor, and then desolder, clean and resolder them. If the problem still persists, replace the parts with new ones.



3. A Fine Vertical Line in the Black Monitor

The First Thing To Do Is To Turn Off The Power!!!!!!!!!!!

Symptoms
Mac SE/30 shows a fine vertical line in the black monitor. In addition, you may be able to see and/or smell smoke coming up from the SE/30. It's burning. Shut off the SE/30 immediately, and pull out the power plug.

Diagnosis
The horizontal sweep circuit on the analog board is broken.
The R19 resistor (220 ohm, 1/4W, 5%) on the analog board is burnt out. 

Solutions
Check the R19. If it is burnt, cracked and/or charred, replace it with a new one.
 

 

[uniserver]

a fried UE8 does that,  from the cap ooze leaking into it.

so your main board needs a recap at the very least.

 

[eR1c]

..I recommend checking all the connections from the CRT to the AB, ...my SE had really bad solder joint cracks that were visible under a magnifying glass (my eyes aren't so good) ...re-soldered and that fixed a lot of my display problems. 

 

[Tonebender]

I've now tested the SE/30 with a different logic board, one from an SE. The board looks fine and I'm fairly positive it works, but the SE/30 is behaving the same: black screen with the vertical line, one plong from the speaker, fan spinning, but otherwise dead. I suppose I need to do what eR1c and some others have referred to -- go through the analog board.

I've also measured the voltages from the PSU/analog board, and they are a bit strange in some cases, although it isn't clear how my low-budget multimeter is showing AC voltage.

 

[Tonebender]

Alright, so I started to resolder some of the solder joints on the back of the analog board, and now the screen is totally dead. No vertical line any more. I didn't resolder many joints, but I did the ones for the yoke connector, and R19 and a few more in the same corner of the board. I also measured the voltages on the external floppy connector on the back of the Mac (as per Classic Mac Repair Notes) and they seem okay (+12.6, +12.6, +5.02, -11.5). This is starting to bug me a bit now...

 

[uniserver]

the se/30 doesn't ever require joints to be resoldered on the A/B

 

[Tonebender]

Good news!

This is almost embarrassing, but I tried adjusting the "cut-off" (brightness) control on the side of the analog board, and suddenly the screen as well and alive. I now see the question mark diskette symbol on boot. Darned, I really should have tried this earlier. But I did have the vertical line thing previously, so who knows what's been going on.

Now I could use some more help, although I don't know exactly where to proceed. This SE/30 currently has an SE logic board in it, so I'm not totally sure how well that works (SE boards should work in an SE/30, right?). But the floppy drive is behaving erratically to say the least. It's generally sluggish mechanically speaking, and when I try sticking a system 6 boot disk in it, it spurts it out (successfully half the time) showing a floppy with an X on it...

 

[Tonebender]

Hmm, now that I think of it, maybe the SE logic board (currently mounted in the SE/30) can't handle the 1,44 MB disk drive in which I try to boot from a HD floppy ...

 

[Elfen]

Chances are your SE Logic Board is not a "Super Drive" Logic Board. Those have a SWIM and enhanced ROMS to handle the 1.4M Floppy Drives. The non-Super Drive boards can only handle the 800K drives because they have an IWM and older ROMS.

Did you take the voltages from the hard drive power connector? The Black wire is "-"/Ground, the Red wire is +5V and the Yellow wire is +12V. The meter should be set to DC, not AC, and voltage setting to 20V (depending on the meter, it could be 50V or some other setting. I have one that has 15V as a setting... go figure).

Since you got the CRT going again, did you swap to the SE\30 board to see if it works? I'm confused about that part.

 

[Tonebender]

Yes, I did check the voltages, but wasn't sure about what they should be. On the harddrive power molex connector, they are 11.9, 0, 0, and 5.4 VDC. The connector to the logic board gives -9.2, -4.9, 0, 0, 0, 0, 0 on the first row (left to right) and 11.9, 5.4, 5.4, 1.6, 1.6, 1.6, 0 on the second row. All measured when not connected. I believe they are okay until further notice.

I would gladly put the SE/30 logic board back in to the SE/30, but one electrolytic capacitor is broken off (my fault), so I'm going to recap the board before I can use it again. I have the correct tantalum caps at hand, so I just need the time to do the solder work now.

 

[Elfen]

The connector readings are a bit scary.

The 11.9 is fine for +12V.

*The 5.4 is a bit high for +5V.

The -4.9 is fine for the -5V.

*The -9.2 is low for the -12v.

The 1.6 I think is part of the video circuitry.

It's the -9.2 and 5.4 are a bit off. Though the -12v (-9.2) is mostly for Serial I/O communications, it is not. The 5v (5.4) is a bit high and all the logic processes uses the 5V.  At this point I think the PSU needs to be recapped.