ironborn65 Posted November 15, 2020 Report Share Posted November 15, 2020 Hi pals, I just got a - externally looking - fine 6100. I tested the power supply: OK. I replaced the 3.3v battery: OK I looked for macroscopic leaking from the capacitors: OK the HD works fine, I connected it to another Mac: OK I turned it on: black screen, no BEEP 5V, 12V stable: OK reset PRAM quick on-off-on It turned it on: black screen, no BEEP, no HD activities I did then a closed inspection at the mother board, and I saw some sign of corrosion (see attached photos) close to some SM capacitors. It did not look so bad to me but I decided to do some cleaning with isopropyl alcool and a cotton swab. WTF!! A small capacitor went off a very very tiny one, I believe it is a capacitor (it is visibile in a one of the pics). The fact that it went off some easily it means to me that the capacitors have leaked significantly. I'll recap the mother board, but the tiny capacitor is very small, probably beyond my skills and tools. Can anyone please provide some comments? Enjoy the photos Please be kind to me thanks best PF Quote Link to post Share on other sites
LaPorta Posted November 15, 2020 Report Share Posted November 15, 2020 All that greenish stuff on the leads of the surrounding components is the result of the leaking capacitors. That stuff needs to be cleaned up, and the caps replaced. Quote Link to post Share on other sites
cheesestraws Posted November 16, 2020 Report Share Posted November 16, 2020 Yeah, you're going to have to give that a really thorough clean before you can really assess it, I think. Where did the cap that fell off come from? Quote Link to post Share on other sites
ironborn65 Posted November 16, 2020 Author Report Share Posted November 16, 2020 the tiny capacitor felt from here, see photo Is it mandatory to solder it back ? Quote Link to post Share on other sites
ironborn65 Posted November 16, 2020 Author Report Share Posted November 16, 2020 I replaced all the capacitors, the picture shows only three of them and the tiny capacitor I was somehow able to solder back (it was rescued from another device, same colour of the original that went lost ). I tested the continuity from each capacitor pin and the trace it's laid, everything looks fine, I checked the polarity numerous times. I assembled it back. Same checklist as above: it chimes as the fist but then I hear the nasty car crash sound, of course still a black screen. I tried with another pair of SIMM I had, known to be working, but with no luck. Ah, the hardware reset works. Any hope? thanks Quote Link to post Share on other sites
ironborn65 Posted November 19, 2020 Author Report Share Posted November 19, 2020 If the Mac plays the crash crash sound after the startup bong can I assume at least the CPU is not compromise? thanks Quote Link to post Share on other sites
bibilit Posted November 19, 2020 Report Share Posted November 19, 2020 Egret chip ? Quote Link to post Share on other sites
cheesestraws Posted November 19, 2020 Report Share Posted November 19, 2020 31 minutes ago, ironborn65 said: If the Mac plays the crash crash sound after the startup bong can I assume at least the CPU is not compromise? Yeah, that is... it being well enough to notice it is unwell, if that makes sense. About how long is the interim between the chime and the crash? Quote Link to post Share on other sites
Daniël Oosterhuis Posted November 19, 2020 Report Share Posted November 19, 2020 Do you have a way to hook a monitor up to it? If so, do this and see if you get an error code. I should note that the 6100 needs the battery to output video at a cold boot, without a battery you will need to reset the machine by either hitting the reset button or quickly power cycling it after the first boot chime, to get a video signal. So don't be alarmed if you get no display on a "normal" cold boot. Quote Link to post Share on other sites
ironborn65 Posted November 19, 2020 Author Report Share Posted November 19, 2020 thanks Daniel, cheesestraws for the reply. I tested the power supply: OK. 5V, 12V stable: OK I replaced the 3.3v battery: OK I recapped the mother board, please notice the replacement of the tiny capacitor (is it?) near C94 C95 C97. It came out and lost when cleaning, I replace with one of the same color from a scrapped device. Monitor connected I turned it on: black screen, classical chime and after about 1 sec i got the chime of death (car crash) I did several tests: reset PRAM quick power cycle remove the RAM SIMM, just the on board RAM switch ROM to the other slot no SCSI cable, no floppy cable Every timer I turn it on: black screen, classical chime and after about 1 sec the chime of death (car crash) Quote Link to post Share on other sites
ironborn65 Posted November 19, 2020 Author Report Share Posted November 19, 2020 12 hours ago, bibilit said: Egret chip ? what is it? Quote Link to post Share on other sites
cheesestraws Posted November 20, 2020 Report Share Posted November 20, 2020 10 hours ago, ironborn65 said: I turned it on: black screen, classical chime and after about 1 sec i got the chime of death (car crash) What happens if you power it on, wait for the chime of death, then do a reset (note, not a power cycle)? 10 hours ago, ironborn65 said: what is it? The Egret is a chip that deals with quite a lot of miscellaneous functions associated with the CPU. It's a bit notorious for getting cap gunk stuck under it and failing for that reason. Quote Link to post Share on other sites
ironborn65 Posted November 22, 2020 Author Report Share Posted November 22, 2020 On 11/20/2020 at 10:31 AM, cheesestraws said: The Egret is a chip that deals with quite a lot of miscellaneous functions associated with the CPU. It's a bit notorious for getting cap gunk stuck under it and failing for that reason. can u please help me to locate the chip? I can not find schematics or a MB layout thanks Quote Link to post Share on other sites
cheesestraws Posted November 22, 2020 Report Share Posted November 22, 2020 38 minutes ago, ironborn65 said: can u please help me to locate the chip? I can not find schematics or a MB layout I don't know anything about the 6100, I'm afraid, I just know what that chip is in earlier Macs. @bibilit might be able to help. Quote Link to post Share on other sites
Daniël Oosterhuis Posted November 22, 2020 Report Share Posted November 22, 2020 (edited) 3 hours ago, ironborn65 said: can u please help me to locate the chip? I can not find schematics or a MB layout thanks It's U11. It's in the right upper corner (with the I/O ports pointing upwards), under C3. If C3 leaked, it's very likely the EGRET has gotten gunked up. EDIT: It's seen in your picture here, 341S0788: Edited November 22, 2020 by Daniël Oosterhuis Quote Link to post Share on other sites
ironborn65 Posted November 22, 2020 Author Report Share Posted November 22, 2020 Thanks Daniel, that area is not very clean, the cap leaked, as you can tell from the greenish around it. At this point I have IMO some options: - desolder it, clean it and put it back. I do not have special tools, I'm just good enough to solder SMD tantalum capacitor, it's probably behind my skills and I do not want to make practice on an Apple MB. - put it the dishwater for a couple of rounds Reading around, a mixture of water and acid citric (lemon) would help removing the conductive acid of the capacitor. Isopropyl alcohol does not help, it's good for removing flux Quote Link to post Share on other sites
cheesestraws Posted November 23, 2020 Report Share Posted November 23, 2020 Citric acid ought to do it. Distilled vinegar is also a good option. Either way, you need to make sure to rinse and dry it properly, though... Quote Link to post Share on other sites
ironborn65 Posted November 27, 2020 Author Report Share Posted November 27, 2020 finally I got it working! Lovely! I did a thorough cleaning, using vinegar, I also re-soldered a couple tantalum SMD, my bad one was loose and it booted up! But ... now the audio is not working, it make some white noise for a minutes or so, then it stopped. It might be another DMS. Thanks you all! Quote Link to post Share on other sites
Daniël Oosterhuis Posted November 27, 2020 Report Share Posted November 27, 2020 2 hours ago, ironborn65 said: finally I got it working! Lovely! I did a thorough cleaning, using vinegar, I also re-soldered a couple tantalum SMD, my bad one was loose and it booted up! But ... now the audio is not working, it make some white noise for a minutes or so, then it stopped. It might be another DMS. Thanks you all! That could be the Crystal Audio IC on the board. On a PowerMac 8100 board that I got from Japan, the caps too had leaked fairly heavily, and it seems to have killed the audio chip, even despite the fact I didn't power it up until after recapping and cleaning. Mine's just making horrible digital noise, so I think that's the DAC in the chip audibly failing. Yours might be bad too, if there are no signs of corossion or damaged traces or components around the chip or other parts of the audio circuitry. The part number on the chip is CS4217, they seem to still be for sale relatively affordable online, though as usual, beware of fake/dead remarked chips from China. Quote Link to post Share on other sites
ironborn65 Posted November 30, 2020 Author Report Share Posted November 30, 2020 still there are strange (to me) issues After re-controlling and re-soldering again some SMDs to try to make the sound work (before committing to replace the sound chip) ... the motherboard did not boot at all, sadness: - silent - with additional RAM, with only onboard RAM - the PSU provides stable and precise voltage - the CPU goes up to 48 degrees centigrade - I replaced the silicone heatsink compound - PRAM battery ok - rapid on/off/on - reset keyboard - recapped of course I was almost due to store it in the RIP section of the self, when is started to show life, flashing bands on the screen first, restart again, then the smiley face, it freezes, restart again ed again .... apparently it works only when warm. The more it warms up the more likelihood that it boots and it remains on till the OS allowing me to work with it, but it might still freeze. Ah, the rest button does not work, all the section is rusty and not in good conditions. I was looking around those STEWARD ICs, any clou what they are for? I could only find a Chinese only web site thanks PS: the camera decided to apply HDR, the pads are not so bad Quote Link to post Share on other sites
ironborn65 Posted December 7, 2020 Author Report Share Posted December 7, 2020 I just to close the thread, I gave up with it, it's unstable. Quote Link to post Share on other sites
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