68kMLA Classic Interface
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| Simasimac Not Going Away After ReCap on SE/30 | |
| Posted by: belgaonkar on 2017-04-10 18:38:13 Hi all, When went to purchase the SE/30 (2 months ago) it booted right up and showed the dead hard drive symptoms but had no hint of "simasimac". I put the machine in 72F climate controlled storage and just recently got around to replacing the hard drive and testing the machine when I noticed the issue. I have cleaned all the Ram and ROM pins with isopropyl and they have been also been tested with known good ones. When I originally pulled the board out of the SE/30 I found 2 caps laying inside (C1 and C13), Im guessing those were completely shot. I took a couple of pictures before sending the board out, but I would like some help in diagnosing the possible issues. Unwilling to ruin an SE/30 board, I have sent it off to be professionally recapped. After the re cap, the simasimac problems are not going away. I noticed that C1 may have some trace issues. Can anyone give me some insight as to what may be wrong? PS. Ive been watching a bunch of tech knights yt videos to see if my symptoms match.  | |
| Posted by: Boctor on 2017-04-11 02:44:06 Those pads for C1 aren't looking so good. Reminds me of my first board, which had failed completely in the "death alley" with the four caps near the VRAM chips. If there are bad traces or lifted/destroyed pads anywhere, a jump wire may be an option, depending on what the schematics say the cap is connected to. | |
| Posted by: ArmorAlley on 2017-04-11 03:39:52 How is your analog board? | |
| Posted by: belgaonkar on 2017-04-11 03:58:51 Looks to be fine, I have ordered replacement caps. Ill attempt to do it myself since they are a bit easier to solder. | |
| Posted by: techknight on 2017-04-11 06:58:20 Thats because you have a rotten trace somewhere, there is an address/data line broken. Probably at the ROM. Take a close look at that. Do you get slow chimes? or no chimes at all? | |
| Posted by: Unknown_K on 2017-04-11 12:34:38 If you look closely at that picture of both sides of the pads there is a trace going to a test point. One side has a mound while the other has a depression and corrosion. While the visible traces themselves are probably ok, some goo could have leaked into the board itself and caused problems. That particular area looked a lot better then others which had lots of cap leakage and solder pads that turned black. | |
| Posted by: belgaonkar on 2017-04-11 13:31:05 I noticed that, hence the reason I mentioned cap C1. Is the board shot or is there hope of fixing it? | |
| Posted by: Unknown_K on 2017-04-11 14:47:33 I can't say. Troubleshooting can be an art that takes quite a bit of time and effort and sometimes all you do is find out why it cannot be fixed. | |
| Posted by: belgaonkar on 2017-04-11 18:56:25 How would I know if it's missing a trace? Just use a multi meter to check the voltages on near by components? Where can I get the Apple Schematic? Ive heard the 3rd party ones are not correct. | |
| Posted by: techknight on 2017-04-11 19:02:26 How about read my post? I am trying to send you down the correct troubleshooting path. Do you get Sound? Do you get good chimes? or slow chimes? | |
| Posted by: belgaonkar on 2017-04-11 19:07:13 Sorry about that. I don't have the board with me yet. It is being shipping from the re-capper to myself. | |
| Posted by: Unknown_K on 2017-04-11 19:20:39 No sound at all. | |
| Posted by: techknight on 2017-04-12 15:04:09 Ah... ok. IF you dont get any sound with Simasimac, thats because you have a broken address/data line at the ROM SIMM itself, or the ROM itself is bad. But sometimes you could have a multiple offender, you got a broken trace at the RAM causing the machine not to boot, but also broken traces at the ASC causing no sound. You will have to figure out which condition the machine is in via troubleshooting. IF C1 were to cause trace damage, you would get slow chimes. | |
| Posted by: belgaonkar on 2017-04-12 16:29:01 The ROM simm has cap C12 near it. The apple sound chip is near C7 right? I need to check the traces near there. | |
| Posted by: belgaonkar on 2017-04-17 15:55:36 Got the board today and had a chance to take a closer look at the caps. Cap C9 doesn't look too healthy. Also, will washing the board with distilled water remove the corrosion on the IC legs? Sorry for all the questions, I appreciate any help.     | |
| Posted by: techknight on 2017-04-17 16:14:28 I see a few reasons why it wont boot, but there is not enough detail. I need a good shot at where the ROM would go. | |
| Posted by: belgaonkar on 2017-04-17 17:04:32 There you go!  | |
| Posted by: belgaonkar on 2017-04-17 17:20:47 Closer up  | |
| Posted by: belgaonkar on 2017-04-19 14:48:45 Any ideas on what trace might be messed up? | |
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