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

I checked the voltages on the same locations in my working SE, and the voltages there are the same, for example -9.3 volts where you say it should be -12, and 5.4 where it should be 5.0. But I don't know, it may be sweating a bit...

 
Alright, so now I've recapped my SE/30 logic board with tantalum caps, but when I turn the computer on, all I see is this:

mac_se30_2016-04-17.jpg.5efcbf8a70f30b9ad51a4e7fb7e7cba0.jpg


I tried this SE/30 logic board in my SE FDHD, which gives the same results, while my SE logic board works in the SE/30 box, which indicates that the error is with the SE/30 logic board.

I also tried booting the SE/30 without RAM simms mounted, and the screen is the same (while the bong is that major chord arpeggio instead).

Any ideas? This is really quite tiresome... :(

 
Thanks for the ideas!
Yes, I get the chimes. With RAM (and ROM) simms mounted, I get the normal single bong. Without RAM (but ROM still mounted), I get what I believe is the slow death chime -- it's a succession of notes which sounds like a major chord arpeggio.

 
can we see a picture of this board you re-capped... i hate tantalums because they can easily cause bridge shorts lots of times.

also flux in the rom slot can cause that pattern... but a slow sad mac is always memory /dead trace issues.

 
Okay, here's a whole bunch of large pics:

2016-04-18_01.jpg.e4b21c0fe4192f5f8f0cbaaa5c87ca79.jpg


2016-04-18_02.jpg.ac335923046bf26caf577b008273a42b.jpg


2016-04-18_04.jpg.1deccaf4983b3c3972784743a07f7194.jpg


2016-04-18_05.jpg.d9a46ba14f4cb577ee5fcc7f20798775.jpg


2016-04-18_06.jpg.90fa59ff73930a89fe5d2543bef670a9.jpg


It's the first time I recap a board, although it's far from the first time I solder things, so it's not the neatest job ever. I know C6 and C9 look suspicious, but they all check okay with the multimeter. While many of the caps don't sit very straight, I made sure they solder joints were good.

In general, the board looks pretty clean, doesn't it?

Underneath the old caps were very faint signs of leakage; nothing that seemed to have flowed around at all. I did clean the whole board after removing the old caps. And I just took some electrical cleaning spray and a toothbrush and cleaned UE8 and thereabouts, but alas, the screen still shows the same pattern.

 
Well, that red maxell has to go bye bye for one thing. 

Getting chime with simasimac is really strange. Although, How does the chime sound? is it clean, or is it distorted or sounds like its off-key? 

Next thing is to check the 5v, and 12v rails. if they are where they should be. 

 
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I'll check the voltage on the battery again, but I seem to recall it's okay. (Yes, I know it should be replaced anyways.)

I'm not sure exactly how good the chime is supposed to sound, so it's difficult to judge, but I haven't noticed anything odd with it. It's not off key, to my ears, but sound quality may be a little distorted, but not very obviously. It's also quite short and cuts off abruptly at the end.

I've already posted the voltages from the analog board in this thread (see previous page and replies). Thing is, this computer works fine with another (SE) motherboard in it, so I figured the voltages are okay.

Here they are again: 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.

 
Those Maxwell batteries explode more often than any other brand of battery.  Probably 90% of the time there's a battery leak, it's a red Maxwell.

 
I'll check the voltage on the battery again, but I seem to recall it's okay. (Yes, I know it should be replaced anyways.)
Dont think you quite understand the severity of it. That battery has to go. no ifs, ands or buts. period. Look at the date code. if its 80s, 90s, GOTTA GO!

 
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Dont think you quite understand the severity of it. That battery has to go. no ifs, ands or buts. period. Look at the date code. if its 80s, 90s, GOTTA GO!
Alright, alright.

But it seems like there's a slim chance that the motherboard is gonna work at all. And if it's not, I'm not gonna bother to find a store that sells the correct battery and waste my money on it. In that case I'm just gonna toss the Maxell in the recycling bin and be done with it.

Any ideas on the simasimac problem? I really appreciate all the help you guys have given me so far!

 
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