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#1 2017-02-15 15:30:47

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

SE/30 Revival Questions

Hey folks, I've recently been trying to revive an SE/30 I picked up at a thrift store. I'm basically a total beginner - very careful with everything (borderline paranoid), but very unaware of how to fix these issues beyond replacing capacitors. I've tried to leverage some online guides, forums, and techknight's (assuming the user here is one and the same) videos on youtube. All of those have been great and I've learned a lot but I'm having some persistent issues and was hoping to get some tips on things I can look for with my issues.

After getting the machine home and doing the smoke test I got a screen just like this:

Mac_screen_pattern.jpg

I familiarized myself with the simasimac error screens here but the image looks like a mix of a few different errors so I'm not totally sure. The vertical bars and checkerboard appear to be related to ram/rom simms so that is where I've tried to pay extra attention.

I was aware of the leaky capacitor issues (I've fixed caps on some older video game consoles) and the caps had certainly leaked so I went ahead and replaced them with fresh electrolytics. All in all the board appears to be in decent shape - the battery had not exploded, the ue8 chip and the sound amp were not nearly as bad as I have seen in several videos/pictures, the pads were in pretty good shape (save for one that I accidentally lifted) - so I was hopeful that the re-cap would fix the problem.

After the re-cap the screen persists but now, on the positive side, I get death chimes (I had no sound before the re-cap).

Things I've tried:

  • Re-capping the board

  • Giving it a good scrubbing (against my better judgement). I scrubbed with a soft bristle toothbrush in warm soapy water, rinsed clean, hit it with the heat gun lightly for about 10 mins just to dry off the surface residue and let it sit for 24hrs

  • Scrubbed the ROM and RAM slots with alcohol

  • Cleaned the ROM and RAM simm pins liberally with alcohol

  • Tried a replacement ROM simm (ordered working off of ebay)

  • Waiting on new RAM simms (to rule out bad ram - but I'm assuming this won't make a difference)

  • Tested continuity from pin 2 in bank a/b slot 1/4 to buffer - I have continuity (thank you techknight)

  • Tested continuity from pin 2 in each bank to it's parallel - I have continuity

Observations:

  • I had an issue removing the 470uf axial capacitor (this appears to be common) - and the replacement was causing a short. I fixed this but doesn't seem to make a difference.

  • In the ROM simm slot, the 3rd pin (looking at the board - rom/ram closest to you - counting left to right) looked bent. I fiddled with it and it should be bent back far enough to contact the simm

  • Testing continuity from the ROM slot to some of the chips around it seems to work EXCEPT for that 3rd pin - no reading on multimeter (I don't know/think this is normal)

  • Testing continuity from the bottom of the board - ROM slot pins I seemingly get continuity all around except from the pin highlighted below (again - I don't know if this is normal)

edited_mb.jpg

  • Testing continuity on R36,R37,R38 - I get nothing

I apologize for the novel length post but I figured I should be as thorough as possible in describing the issue. Any tips or things to look for would be greatly appreciated. My fear is that the board might simply be too far gone at this point but cosmetically it really looks fine.

If posting more pictures would help please let me know and I will certainly get those up.

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#2 2017-02-15 16:47:48

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: SE/30 Revival Questions

UE8 issue?

Any pics of that area of the board?

Charles is the expert there. Here's a post he made.

https://www.thinkclassic.org/viewtopic.php?pid=776#p776

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#3 2017-02-15 16:55:19

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

I don't have any pictures of that area handy currently but this evening I will certainly post.

Thank you for the link - I will examine the IC a bit more and see if I can verify this as an issue. Assuming it needs to be replaced is there anywhere reliable to purchase it?

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#4 2017-02-16 00:36:05

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

I've got a better picture of the ue8 here:

IMG_20170215_191938.jpg

I think this may be the issue. Doing the continuity tests to the corresponding pins on uc7 and uc6 shows that maybe half of them are working. I guess the next step would be to run jumpers just to see if I can get it working.

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#5 2017-02-16 14:54:09

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: SE/30 Revival Questions

I think you are headed in the right direction. Schematics for SE/30 would probably help you out if you don't have them. I am quickly wading into the deep-end on my knowledge with this though. smile

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#6 2017-02-16 15:11:41

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

I found what I think to be the correct schematics here - although I'm having a tough time making heads or tails of them. I'm certainly in over my head a bit but I really appreciate the help!

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#7 2017-02-17 01:54:08

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

Welllll - it looks like perhaps I ran the jumpers wrong or something. After jumping the seemingly dead pins from ue8 to their corresponding pins on uc6/7 and testing for continuity it gave me the same screen and then quickly changed into a garbled wavy mess. I did order a replacement from mouser and I have some chip quik coming to pull up and properly repair ue8 so hopefully that will do the trick neutral

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#8 2017-02-20 18:46:20

bobo68
Member
From: Germany
Registered: 2015-07-07
Posts: 22

Re: SE/30 Revival Questions

UC6, UC7, UE8 etc. are on this page: Page 5-> Video Interface. What are you struggling with?

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#9 2017-02-20 19:08:04

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

Those are indeed the schematics I'm using. I was correct in my previous post when I guessed I had run the jumpers wrong (numbered the pins wrong). Upon further testing ue8 did/does have continuity to uc6/7. I'm still planning on replacing it as I had already ordered replacements and I've removed the original but I'm skeptical it is going to resolve the issue.

The issue I'm continuing to run into is the combo jailbars/checkerboard with death chimes. I've recapped and cleaned the board thoroughly - ue8 was the next in line for possible solutions.

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#10 2017-02-20 19:31:20

bobo68
Member
From: Germany
Registered: 2015-07-07
Posts: 22

Re: SE/30 Revival Questions

Numbering is always from the marker on the chip (or even on the board in this case - the white dot) counter clockwise starting with 1.

You might want to check more of the stuff that you see in this picture. e.g. the sound stuff (UE10, UB10, UB11, the caps in between) and the address line (A0, A1, ...) connections to the Glue chip (the big one at the bottom, UI8)
2015-01-18%2020.58.29.jpg

This info card may help:
Macintosh%20SE:30%20Mainboard.jpg

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#11 2017-02-20 19:59:25

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

Awesome. Thank you! This should come in handy. Will report back in after ue8 goes back in and I can test a few more things.

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#12 2017-02-24 04:20:23

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

Well I have to say I'm a bit stumped.

I got ue8 back in - not totally pretty because one of the pads came half off with a leg but the replacement seems alright just slightly off center to accommodate the missing pad area. I revisited cleaning the board as I had just done a cursory scrubbing initially. I decided to throw the board into the dishwasher and give that a go. After it was done I put it in a bath of 99% IPA and a bit of window cleaner (for the ammonia), hit it lightly with the heat gun to dry it some, and left it to air dry for 24hrs. Getting home and testing today yielded the same result with the jailbars and checkerboard pattern from the initial post.

I've been sitting here all night testing continuity to verify the address lines per bobo's suggestion - from uk6 to ui8 (glue), from ui8 to ue10, and from the pins on uk6 to the corresponding pins on u*8 chips. I'm working on testing ue10 to ub10/11 but those also appear to be checking out ok. Any more suggestions? neutral

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#13 2017-02-24 13:29:52

ScutBoy
Member
Registered: 2014-05-25
Posts: 159

Re: SE/30 Revival Questions

That SE/30 "info card" is awesome - any more like that for other models out there? I don't recall seeing this or any others on the wiki...

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#14 2017-02-24 14:13:13

bobo68
Member
From: Germany
Registered: 2015-07-07
Posts: 22

Re: SE/30 Revival Questions

Does the machine boot, i.e. do you have desktop or see the mouse pointer move underneath the stripes and checkerboard?

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#15 2017-02-24 14:34:33

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

Bobo - I get exactly this screen without a cursor or anything.
Mac_screen_pattern.jpg

When I have the speaker plugged in I get death chimes loud and clear. This is the screen I've been getting since I picked it up and before I recapped it - the only difference is that after the recap I'm now getting sound. I've tried different ram simms and rom simms but nothing has seemed to make a difference. I'm guessing there has to be a short somewhere on the board but the traces all look really good and the board itself is really clean - no battery explosion only leaky caps.

Any suggestions would be awesome as I feel like I'm scraping the bottom of the barrel. Given kind of the 'common' fixes I'm down to probably looking at the bourns filters but I'm not too sure how to test if those are working.

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#16 2017-02-24 16:09:46

bobo68
Member
From: Germany
Registered: 2015-07-07
Posts: 22

Re: SE/30 Revival Questions

When my SE/30 had simasimac it would still boot and you could see movement through the patterns. There are some random dots on your screen, that's why I asked.

techknight pointed out on 68kMLA: "slow death chimes = cant see RAM = check the traces to the RAM slots, the buffer IC just below the slots near one of the good leakers, and then check the 74F258s for stuck logic gates.".

Do you have a correct RAM configuration? AFAIR memory size in bank A has to be >= that in bank B.

But I'm starting to guess because it seems that you checked all relevant connections on the mobo...

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#17 2017-02-24 16:24:20

stinthehuman
Member
Registered: 2017-02-15
Posts: 10

Re: SE/30 Revival Questions

So when I first got the machine both banks were full - as part of my testing process I've tried filling both banks, only bank A (with both 4 simm sets indv.), and purchased a known working 1mb set to fill bank A (just to rule out bad ram simms). All of those resulted in the same screen and chimes. I checked the continuity from pin 2 in bank A/B to the buffer IC and the parallels from bank A to B (pin 2 in bank A slot [n] to pin 2 in bank B slot [n]) and all of that seems up to snuff. I'll check out techknight's post to see if maybe there is something that I'm missing - I checked the buffer based on one of his YT videos.

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#18 2017-10-02 18:29:20

cbmeeks
Member
From: Hixson, TN USA
Registered: 2017-07-24
Posts: 4
Website

Re: SE/30 Revival Questions

Have you been able to get this to work?  I noticed you used radial caps instead of SMD.  I did the same thing and part of me feels bad about it.  lol

My issue with my SE/30 is horizontal stripes.  But this post is motivating me to get it back out and try fixing it again.


Cat -- the other white meat.

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