2 x SE/30s: SimasiMac on one, JailBars+boot on other

[TheoryBoy]

Hi maybe some one can help

I have 2 SE/30s both have been idle for over a year, the SimasiMac one did boot over a year ago, I had a little trouble with SimasiMac back then but after a few boots its started up ok. I knew I would have to do the caps which I did last week. I also spotted a bit of battery leak, so that has been cleaned up and replaced. Even after replacing all the caps I still get SimasiMac. The Memory has been tested on an LCII and checks out fine, this memory was originally in it when it did boot fine. 3.6V Battery is new.

The other one, must the same story as the first, but with jailbars. The odd thing is it bongs and boots from HD but the screen still has jailbars. Some times they are rolling jailbars (left to right/fast) At first I thought it was a bad analog board, but I have used an se board to verify that I get clean video. So the problem lies on the motherboard. I have replaced the caps on this board also, but made no change. Again the memory has been verified. 3.6V Battery is new.

I would be happy getting one going between the two and my theory is that the video section of the second one is damaged in some way, but I dont have the pinouts of the SE video connector to do a trace back.

Can anyone help ?

Thanks

 

[applefreak]

Repair Macintosh SE/30

http://www.biwa.ne.jp/~shamada/fullmac/repairEng.html#SimasiMac

 

[wally]

Video (9) Horizontal drive (10) Vertical Drive (11). But the trapezoidal area bounded by (UC6, UI6, UG8, UA8), and additionally the ICs UJ6 and UK6 are all video related, and to make signal tracing matters more complicated there are five mystery PALS. An easy step is to remove (one at a time) all socketed PALs and the Video ROM (taking care to ground yourself to prevent ESD), clean the leads if necessary and reinsert to resolve any aging socket contact issues. If you have a scope and cable extensions you can look thru the entire area for marginal levels; everything should be logic levels. UD8, UE8, UF8 are particularly vulnerable to C7 leak corrosion and shorts both to the PC traces and internally into the IC leadframes themselves. If you are a skilled solderer you can cut out these three ICs, remove the lead stubs one at a time and install SMT replacements after carefully inspecting and repairing the traces underneath these particular ICs.

With respect to battery leakage, D1 keeps the normal power from charging the battery, and D2 keeps the backup battery from trying to power the +5 rail when the machine is off. Both are SMT versions of 1N914. If your version of CPU PC board has C12 near the RTC, leakage from this cap can spoil RTC operation and cause several kinds of battery failure if either diode leaks in the reverse direction more than spec.

 

[TheoryBoy]

:b&w: :b&w: :b&w: Success. Thank you so much wally, you advice was accurate and concise. While it was not the exact solution , it started me on a road that lead to a sweet booting SE/30.

After replacing all of the chips from UG8 to UA8 with no chance I went searching for the video schematic a little deeper. Link below. After loads of tracing with the DMM I found a possible cause.

It turns out that I had faulty video memory. I had a short between pins 1&2 on UC7. The short was caused internally in the memory chip, and this was causing vertical bars on the screen. It turns out that the Hi Res Mac II Graphics card uses the same memory chips, and quick snip and relocation lead to partial success.

I now had video but was covered by white bars, about 5mm wide and still vertical across the screen. I then replaced the other memory chip which cured all video artifacts.

Thanks again I have included pics of work in progress and finally my finder up and running.

Video Schematic found on web.archive.org.

http://img264.imageshack.us/img264/5788/videowg3.gif

http://img510.imageshack.us/img510/2515/solderingzv5.jpg

http://img386.imageshack.us/img386/9179/videomemks9.jpg

http://img101.imageshack.us/img101/9866/osesbu6.jpg

 

[wally]

[] ]'> Wow, great detective work and determination! Enjoy your SE/30! [] ]'> Looking at your pictures and the relatively clean uncorroded pads on the video memory chips, this makes me wonder if some significant percentage of the SimasiMac cases are actually just bad plastic packages of certain memory chips, and not necessarily anything to do with cap leakage other than also taking several decades to develop... [] ]'>

 

[JDW]

Well, if anyone has any spare video memory chips, I certainly could put them to good use. I've tried everything to get rid of the SimasiMac bars on one of my SE/30 logic boards (cap job didn't do the trick), but until reading this thread, I thought it was a lost cause. Now it would seem a video chip swap might do the trick. But alas, I don't have any spares handy.

So again, I'd love to give some a try, if you could spare them!

 

[TheoryBoy]

Well, if anyone has any spare video memory chips, I certainly could put them to good use. I've tried everything to get rid of the SimasiMac bars on one of my SE/30 logic boards (cap job didn't do the trick), but until reading this thread, I thought it was a lost cause. Now it would seem a video chip swap might do the trick. But alas, I don't have any spares handy.
So again, I'd love to give some a try, if you could spare them!

There are plenty more on that Mac II graphics card [] ]'> PM me your address and I can post them to you. (I am in Ireland so it could take a bit of time to get to you, about a week to US)

Unfortunately due to limited equipment, I can only snip them off , so the pins wont be full length. You will have to snip the pins on your end too leaving as much as the pins as possible. Then its only a matter of lining up and soldering.

I am not sure what success you will have, as this se/30 was still booting even with the 'jail bars'. So the problem had to be on the video side.

 

[JDW]

TheoryBoy, I certainly appreciate your kind willingness to ship me some replacement chips. But since you mention that your board would boot, even before you replaced the video chips, it is unlikely they would work on my board. My SE/30 logic board won't boot at all. No chimes either. I switch on the Mac and those horizontal lines appear, and there is no disk drive or any other activity in the machine. And again, I replaced my caps (every single one of them) on this machine, so I know it can't be that. And since I have another SE/30 logic board that works fine with that analog board and CRT, I know for a fact it's a problem with the other logic board only, not a problem in any other area of my machine.

Sure wish I knew the root cause those. For in the past, this particular logic board worked fine. And then one day I connected it and it had those SimasiMac-like horizontal lines at cold boot. (But the machine won't boot.)

I even bought a TechStep off EBAY to diagnose the problem, but since it won't boot or show anything other than the horizontal lines, even the TechStep cannot assess anything other than the voltage (which is within spec, by the way).

 

[oscaracso]

TheoryBoy, I certainly appreciate your kind willingness to ship me some replacement chips. But since you mention that your board would boot, even before you replaced the video chips, it is unlikely they would work on my board. My SE/30 logic board won't boot at all. No chimes either. I switch on the Mac and those horizontal lines appear, and there is no disk drive or any other activity in the machine. And again, I replaced my caps (every single one of them) on this machine, so I know it can't be that. And since I have another SE/30 logic board that works fine with that analog board and CRT, I know for a fact it's a problem with the other logic board only, not a problem in any other area of my machine.
Sure wish I knew the root cause those. For in the past, this particular logic board worked fine. And then one day I connected it and it had those SimasiMac-like horizontal lines at cold boot. (But the machine won't boot.)

I even bought a TechStep off EBAY to diagnose the problem, but since it won't boot or show anything other than the horizontal lines, even the TechStep cannot assess anything other than the voltage (which is within spec, by the way).

hi! i think i have the exakt same problem. bought myself a mac classic II for 9$(90 swedish krowns) pluged it in and all i see is these horizontal black and white bars. i hear a blip, but it comes exatcly when i turn on the power so i dont think its a "booting-blip" then nothing happens.

i later got it open, look at the motherboard to see if anything was a little loose or something. took away the plastic cover on the analogboard(is it the name of the power board??) and then i put it all back and put in the powercord. BAM! it shortcuicute and m whole apartment whent dark.

opend it again and looked at the analog board and it where all black from the shortcircuit where the powercord goes.

then i couldnt put in the cord anymore cous it would just shortcircuit, even with the power knob off. and then after two days i tried it again. then it just worked.

but all the same. just these horizontal bars.

did you fixe yours? if you did i be happy to here how you did it.

heres a picture oif mine

 

[JDW]

No, my dead SE/30 logic board is still dead. I tried everything to fix it, in vain.

But I just took a look at your photo, and you have a very DIFFERENT problem than my board has. You have THICK VERTICAL bars. I have THIN HORIZONTAL lines. Thick vertical lines are a different problem altogether.

 

[oscaracso]

is these bars more similar??

i just took a look at this page and he siad that the problem was a leak of the electrlytes?

he put in the dishwasher...

link:http://www.oldmac.de/classic203.html

you need babelfish if you dont know german: http://babelfish.altavista.com/babelfish/tr

and heres another guy that just put it in a warm bath.

i think this might work. im gonna do some more detective work and then mabey try it out

 

[JDW]

No, those bars do NOT look similar.

Please allow me to define terms:

Vertical = up/down -- your problem

Horizontal = left/right -- my problem

Now as to the definitions of "thick" and "thin," I will leave that to Merriam Webster. :b&w:

 

[oscaracso]

aaa sorry.

mixed it up.

ok. but i will look into those horizontal to if i get across it. if i do i promise to post it.