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bertie

Newbie Macintosh SE/30 Repair need help (sorry)

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Hate to ask, but been reading this forum, watching videos, etc. for 2/3 weeks and have got to a point where I'm stuck.

 

Background; I recently purchased a Macintosh SE/30 from eBay listed as powering on but nothing on screen. Wanting a new project, I purchased it and yes, no boot chime, no display, but fan & HDD do spin. Idea was to have a go at fixing it otherwise create a funky R Pi retro gaming machine. Board looked really clean, no obvious leaking caps or battery.

 

Following the numerous guides/video here and elsewhere I've:

Washed in white vinegar, then washed & soaked in soapy water and rinsed - tested and now get a boot chime, still no display

Removed & replaced all capacitors with new Tantalum as per https://wiki.68kmla.org/Capacitor_Replacement#Macintosh_SE.2F30_.28630-4198-11.29

(Only difference is I have a Electrolytic cap for C6)

Positive pad came off C6 so have a jump wire to pin 7 of UB11 after checking schematic and saw others had done this.

Replaced battery as read 0v on meter (and was from 1998)

 

Powering on I get a boot chime, HDD appears to be loading OS as light flickers a lot on the front. There is also a slight glow in the glass end of the tube. All capacitors on the analog board and inside PSU look ok.

 

I'm guessing there is now an issue with the tube but haven't found any details for checking this. Can anyone help? Got to a point where I'd like to get it working, even though my original idea was to give it one go then gut it.

 

Thanks

Richard (UK)

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Welcome to the 68kmla Richard. Don't feel sorry because you need help, this is why most of us come here for.

 

So, first things first, have you checked the brightness knob? It could be turned all the way down...

Some solder joints could be cracked on the analog board. It happens a lot. Give the Mac a good smack on the side. If the screen comes back on for a second or so, you'll have to re-do most if not all the connections on that board (especially around the yoke connector).

 

Your logic board could also be malfunctioning. I really hope that's not the case. Even though you can't really see it from the outside, some chips could be rotten. Are the ports on the back really clean or is there a bit of rust on them? It really all depends on how and where the previous owner stored it.

 

Best of luck!

 

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It's probably as easy to get another compact mac as it is to get a PDS graphics card ( say from Lapis, Radius, Micron or RasterOps ). Either way, replacing the tube or using another monitor via the PDS graphics card will tell your tube is the problem.

To be honest, I've never come across a CRT in a compact mac failing. Usually the caps on the analogue board, motherboard or PSU fail first, the motherboard is damaged by the battery or, at worst, the screen has burn-in. Still, there is no reason why it shouldn't fail.

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Thanks for the replies!

 

@BadGoldEagle

Brightness control - yes checked this, though it was bent (someone had previously removed the case/board and not aligned it by the look of it) Would this prevent display if circuits cracked?

 

@ArmorAlley

Yes thought about a graphics card but couldn't find one, and suspect it is something board related.

 

@techknight

Feared it might be something drastic like that. I don't have / know of anyone with a chip station. Is there anyone in the UK that I could send it to?

 

Is it worth pursuing, or do I ditch and move on :-/

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Lets see if someone based in the UK is chiming in here, otherwise send it to me if you want. Sending it to Germany and back is at least a little bit more cost effective than sending it to someone here from the US.

I can test the LS166 at UE8 and the muxes and shift registers next to it as those fail as well sometimes and replace them if needed.

 

Can you post a few pictures of those areas of the board?

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You have the following in London:

 

The Macsmiths
 
 
 489 Hackney Rd, London E2 9ED, UK
 
Tried to have a look at it when i was there last year, but did not have time left.
 
 

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@Bolle

Sorry for the delay, photos attached. Happy to take more if needed.

 

Messaged Macsmiths, see if it's something they do, otherwise I'll get in touch via DM @bolle and organise to ship to you.

 

Aside, decided it's best to give it a chance of repair as the SE/30 seems a popular classic Macintosh. Have sourced a shell for my Retro Pi project instead. Win Win!!

IMG_3126.JPG

IMG_3127.JPG

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Hi Richard - welcome!

 

I live a couple of miles from MacSmiths. As far as I know they only fix modern Macs. They didn't seem very interested in chatting about vintage Macs when I went in a couple of years ago despite their shelves being full of old Macs, a TAM, some Apple IIs and a Lisa :(

 

I have an SE/30 that may have a similar issue. I'm not sure though. 1 of my 3 SE/30s stopped working recently and I managed to fix it yesterday, I was worried it was UE8. I have another I bought non-working that I've managed to get almost working but has vertical lines, although I can see the boot background gray, the mouse cursor, and the 'looking for boot' floppy disk icon through them. I suspect this could be UE8 but I'm finding it difficult to find others who found a fix for this issue - I have seen a few photos of the same issue.

 

What's showing on your screen on boot? Nothing?

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@techknight is the only way to replace/fix UE8 with a hot gun for removing the chip, and is it possible to get replacements?

 

Ive never done IC de-/re-soldering, and I assume my basic soldering set up wouldn't be up to the job.

Edited by james_w

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Hot air will be the easiest. If you are going to replace it anyways you can carefully cut the legs and remove them one by one using wick and your iron.

When putting the replacement back on again you can use hot air again but I find it a lot easier to use an iron to drag solder.

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@james_w

 

I just replaced mine yesterday with this - https://www.digikey.com/product-detail/en/texas-instruments/SN74LS166AD/296-33968-5-ND/1590375

 

Works just fine.

 

Edit: I used the drag solder technique to remove the chip. Be careful not to apply too much prying force as the solder pads are easy to rip up, especially while hot. Like Bolle said, Hot air re-flowing tool would be ideal.

Edited by hfrazier

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@Bolle @hfrazier cheers for the tips - I am such a novice at soldering, I didn't know about the drag technique before. I've watched a few youtube videos and looks like something I could manage so I'll order some replacement ICs soon

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Honestly I got lucky and half of the IC pins popped off (solder between the pins and the pads gave way on one side) ... (which I honestly have taken advantage of with the 'twist technique' of removing the old SMD caps on logic boards before)

 

But anyways, Dave Jones' video on drag soldering may help.. a quality soldering iron ant correct temperature setting makes a big difference. (Also his other videos are awesome, everybody here should watch.)

 

 

 

Edited by hfrazier

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Bertie's board just arrived today and I had time to throw it onto the bench for a quick check.

It is booting fine. SCSI, floppy, sound, serial ports and ADB are working.

Onboard video shows up in TattleTech, so at least it can see the Video ROM.

 

IMG_4248.thumb.JPG.d55d28d819f7a4d3c51e8695af5b01eb.JPG

 

Now to probe the video signals and see where that leads...

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9 hours ago, techknight said:

I think its UE8. Did you change it? 

 

Looks like that's the case. I took the whole Ux8 gang off the board and run them through the tester. All but UE8 passed the tests.

Had to order a new one as it seems I ran out of LS166s. Will post an update if that was the only problem once the new chip is here.

In the meantime I will clean up the board a little bit.

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ive seen UE8 fail dozens of times. thats why I mentioned it in the very beginning. Sure it could have been an open trace but it usually just fails. 

 

I have used the HC in place of the LS and it works fine as well. 

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So @Bolle repaired my SE/30 board and arrived back yesterday (thanks again!!)

 

All back together and have a display!! YAY!

 

? mac icon, which is to be expected as I never knew if an OS was installed or if the SCSI HDD is still 'alive' - so will hunt down some OS7 floppies and see.

 

One new issue, is that the screen flickers and wobbles, more if I tap on the left side (read this somewhere) so might have a broken solder / bad cap on the analog board?? I even ended up with a single white line down the middle at one point, a harder hit on the side brought the display back.

 

Thanks again for everyone's help btw!!

 

 

IMG_3230.PNG

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