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SE/30 no fun with new purchase


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Hi, 

 

Yesterday I got a package containing SE/30. Fact the PDS cover was lying separately told me it was a bad sign (probably the box was dropped). When I turned it on, it started with chime, gave me a jittering sound  and horrible smell of burnt plastic. Immediately turned it off. So I guess the entire display needs replacement (?) The white tab on the neck of kinescope seems tilted. Is there any visible sign of completely dead CRT?

 

On the bright side, motherboard seems to be working, the small battery leakage didnt get out this little compartment. I will recap it in a local shop. 

 

 

 

 

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When my first Classic came, it had been dislodged too - just plug it back in and see if it'll work. Before doing so, make sure that you haven't turned the thing on in a while, and GROUND THE CRT!!! - also, stay away from the flyback transformer, and you should probably be fine

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I'm no expert, but the jittering sound and the smell of burnt plastic sound like a burned out flyback transformer. That can happen anytime due to age.

 

The tilted white tab looks ok, as Jaek says it can just be gently pushed back on. But if you're planning to recap, you might want to remove the analog board as well (observing all proper voltage precautions, do you know how to discharge the CRT?) and study it closely. Larry Pina's Repair and Upgrade book describes how to locate and replace burned out components on the analog board. Most likely the picture tube is fine, the yoke doesn't look broken.

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The yoke board is significantly dislodged (perhaps from a rough shipping ride), you need to reseat this (push it back down) - don't bother if the glass around the yoke is cracked though.  Before powering it on, check the analogue board for any charred components/smell, and gingerly power it up ...

Edited by Byrd
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Repair book: courtesy of maccaps (hope this is ok):

 

http://maccaps.com/MacCaps/Repair_books_files/Macintosh%20Repair%20and%20Upgrade%20Secrets.pdf

 

The physical book is also widely available (there are several copies on ebay complete with items for $30), and can be worth purchasing just for the included disk and ruler. I actually own the physical book, and find the physical copy very useful for quickly flipping back and forth; I am seriously considering buying another copy just to get the bookmark/ruler, which I once had but have long since lost!

 

The same author wrote several updated volumes for later macs, as well as The Dead Mac Scrolls. Great stuff.

 

(The original volume linked covers both the Plus and the SE - the SE/30 uses the same analog board as the SE.)

 

OP: Given the symptoms already reported, there are almost certainly burned components on the analog board that need to be replaced before you try starting up again. One bad component can take out several others when it fails. This may have already happened, but might as well not aggravate the problem.

 

If you need replacement components, there are flyback transformers on ebay for $30, search recent discussions for details. I'm still trying to figure out the best components to use to replace some other parts (e.g. C3 and J1 - I have a burned analog board and a dying flyback of my own, on two different computers!).

Edited by tanaquil
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Was it reportedly working when you bought it?  I'd still say the disloged yoke board would have caused some of the bad faults you experienced.  You could make a good proper SE/30 if you can source a SE by interchanging the plastics chassis etc.

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Byrd: yes, I have a picture showing the computer as fully working (incl. screen)  just before the package pick up. 

 

 

Originally this seller offered local pickup only, so I guess above description must have been true. I just convinced him to send it to another country... 

 

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I tried to start up an SE/30 with a dislodged yoke board (I didn't realize it was loose until much head scratching ensued) and the only symptom was black screen/no video, while other operating sounds proceeded as normal. I doubt that was the cause of anything.

 

If you can get a cheap local SE, even better (than putting the SE/30 motherboard in a working SE) would be to use the SE guts to replace non working components in the SE/30.

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ok here's quick update to my SE/30. Took it to retired university technician with 45 years experience, who opened it up. He disconnected it from a yoke board and found a separate piece of glass from CRT neck, so it was degassed for sure. On the other hand he tested flyback and said it was fine. Too bad it's harder to find a working CRT these days than flyback you can get new old stock on eBay. Agreed to replace CRT if I find one.

 

Should I throw entire CRT to the garbage (well technically give it to electronic waste center) or save some parts of it (like cables)?

Edited by CharlieFrown
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Oh, too bad about the CRT. I guess your first instinct (blaming damage in transit) was the right one after all.

 

I have definitely seen advertised-good 9 in CRTs coming up on ebay, and not for outrageous prices - I think there is a seller offering them in the Trading Post right now as well. Good luck!

 

By all means save the cables, why not? If they test bad with a new unit (don't know why they would) you can always throw them out later.

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  • 2 months later...

ok here's an update, I bought CRT on eBay, supposedly taken from Mac Classic, but the yoke cable was plug and play.

After transplantation, keeping my fingers crossed I turned it on, ping, happy mac, no arches of electricity...that's good. 

 

It boots just ok, but the screen seems distorted, havent tried any adjmustment, windows are visible when dimmed.

DO you think I got broken CRT or just another thing? Brightness is really nice, no visible burn ins. 

 

 

 

 

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After any CRT/ Analog Board Transplant, you NEED to perform adjustments. Don't worry your CRT is fine.

 

What you need to do:

1/ Turn down Cut-Off ! Seems like your previous CRT was kinda weak (logical). This one isn't and it requires less than your old dead one.

2/ Reduce Width. The display should measure 7.11 inches wide.

 

You can do these adjustments with the computer on, but you need a plastic or insulated screwdriver. I used kebab skewers on my Classic II.

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There are adjustment's you have to make on the analog board... You need the plastic adjustment tools or use something non conductive.. You can use a small screwdriver if you are experienced but it's not recommended.. It's on the side facing outward and should have a plastic white shield over it.. There is small holes where the adjustments need to be made.. Just be careful.. if there is no plastic shield and if your not comfortable I would have that experienced tech you know do it..

 

Kebab Skewers is an awesome idea!!!

Edited by aplmak
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There is a transistor on the "video board", (the one that connects to the back of the CRT), you should replace it, should be a 2N3906 by memory.

I also had a gassed CRT and after replacing it it did, the same thing, replacing that transistor fixed the problem

Edited by Ferrix97
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