68kMLA Classic Interface
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| iici astec psu just died yesterday | |
| Posted by: Jon183 on 2017-11-25 23:54:59 Hi everyone, I powered on the iici for about a minute and it never wanted to turn on again. I removed everything and I have nearly finished recapping the board and cache card and washed them, just have to order the axial caps. I shorted pin 9 and 10 (5v trickle and pfw) on the psu and it turns off immediately after shorting on, not even a second, it makes a click sound for on and then click for off. When pins are constantly shorting, PSU oscillates apparently. View attachment 21262 View attachment 21263 View attachment 21264 View attachment 21266 View attachment 21267 | |
| Posted by: BadGoldEagle on 2017-11-26 04:06:44 I wouldn't trust any of those 25+ year old capacitors... I'd recap that PSU first and then if it still doesn't work, we'll have to troubleshoot. I know nothing about IIcis and their power supplies. But I do know that every LC PSU should to be recapped by now and since the IIcis are more or less contemporaneous with the LCs, that's why I think caps are the culprit here. Caps are a common failure on any old PSU anyway.... | |
| Posted by: techknight on 2017-11-26 06:57:47 the other thing that is becoming a common failure point are the opto-isolators. If its not the caps, then it could be that. But without troubleshooting its really hard to tell. | |
| Posted by: IIfx on 2017-11-26 12:39:47 Just an anecdotal observation of mine; the GE PSU for the IIcx/ci seems to be more reliable. Out of my sample size of 2, the Astec that came with my IIcx is dead, while the GE that came in my IIci works great even under heavy load with a fast disk and Radius Rocket. Are the designs of the Astec and GE power supplies significantly different? | |
| Posted by: Jon183 on 2017-11-26 14:49:02 I guess I can do a recap next week, even for the two large caps. | |
| Posted by: Compgeke on 2017-11-26 17:14:51 It's the caps almost certainly. They tend to fall short circuit on the 5V rail and sometimes even leak. My IIcx Astec had leaky and dead shorted caps. | |
| Posted by: Jon183 on 2017-11-26 20:01:27 Ill put up a list of caps. | |
| Posted by: Jon183 on 2017-11-26 20:07:56 4700pf 250v box x2 4.7uf 400v 47uf 25v 470uf 200v x2 100uf 35v 180uf 16v 470uf 16v 4.7uf 50v x2 1000uf 16v 2200uf 16v 1500uf 10v x2 2.2uf 50v | |
Posted by: rickrob on 2017-11-30 18:45:514700pf 250v boxI was just about to ask if anyone had a list of caps for the Astec PSU's -- The PSU in my IIci still works, but might as well re-cap it. I'll find the part numbers at Mouser and add to this post. | |
| Posted by: Jon183 on 2017-11-30 18:58:56 Well its good to know the list is useful, I will make a list of caps for everything I come across that I cant find online. | |
| Posted by: rickrob on 2017-12-03 19:46:52 This is what I ordered from Mouser Mouser # Mfr. # Manufacturer Customer # Description 647-UPT2D471MRD UPT2D471MRD Nichicon Aluminum Electrolytic Capacitors - Leaded 200volts 470uF 22X40 20% 647-UPJ1C102MPD UPJ1C102MPD Nichicon Aluminum Electrolytic Capacitors - Leaded 16volts 1000uF 10x31.5 20% 5LS 647-UPM1C222MHD UPM1C222MHD Nichicon Aluminum Electrolytic Capacitors - Leaded 16volts 2200uF 12.5x31.5 20% 5LS 647-UHE1A152MPD UHE1A152MPD Nichicon Aluminum Electrolytic Capacitors - Leaded 10volts 1500uF 105c 10x25 5LS 647-UPM1C471MPD UPM1C471MPD Nichicon Aluminum Electrolytic Capacitors - Leaded 16volts 470uF 8x20 20% 3.5LS 647-UPJ1C181MED UPJ1C181MED Nichicon Aluminum Electrolytic Capacitors - Leaded 16volts 180uF 6.3x15 20% 2.5LS 647-UST1H4R7MDD UST1H4R7MDD Nichicon Aluminum Electrolytic Capacitors - Leaded 50volts 4.7uF 5x7 20% 2LS 647-UPW1H2R2MDD UPW1H2R2MDD Nichicon Aluminum Electrolytic Capacitors - Leaded 50volts 2.2uF 5x11 20% 2LS 647-URZ1V101MPD1TD URZ1V101MPD1TD Nichicon Aluminum Electrolytic Capacitors - Leaded 100uF 35 Volts 20% 3.5mm 647-UPW2G4R7MPD UPW2G4R7MPD Nichicon Aluminum Electrolytic Capacitors - Leaded 400volts 4.7uF 10x20 20% 5LS 647-UPM1E470MED UPM1E470MED Nichicon Aluminum Electrolytic Capacitors - Leaded 25volts 47uF 6.3x11 20% 2.5LS 80-PME271Y447MR04 PME271Y447MR04 KEMET Film Capacitors 250volts 4700pF 20% LS 10.2mm 80-PME271Y433MR30 PME271Y433MR30 KEMET Film Capacitors 250volts 3300pF 20% LS 10.2mm | |
| Posted by: Jon183 on 2017-12-03 21:17:44 Good luck, recapped a TDK LC PSU just then, it was 100% lifeless before, now it works fine. When I recap my IIci, hopefully it will work again, it was for the 5 seconds I first powered it on. | |
| Posted by: rickrob on 2017-12-09 19:23:55 Worked out great. Recapped the power supply and it started right up. My iici is 100 percent recapped, mobo and cache card too. | |
| Posted by: Jon183 on 2017-12-12 20:24:24 My IIci supply does the same thing, even with all the new caps (expect for the two largest ones, they were too expensive). It makes the MB light blink twice and nothing more. Should I follow this guide? http://www.shobaffum.com/iici/trickle.pdf Logic board fully recapped, cache card not installed or recapped until my chisel tip for SM soldering arrives. | |
| Posted by: Bolle on 2017-12-12 20:38:30 You might want to also have a look at that:  C10, C12, C13 leak heavily onto the UE13/UD13 area. Check if those logic ICs are still good. They tend to fail due to cap goo which results in all kinds of weird power issues, like the machine won’t power on or off, won’t stay on, etc. | |
| Posted by: Jon183 on 2017-12-12 21:29:33 While I did swab under the caps, I didn't clean it properly, I shall look around the area and report my findings when I resume working on it. | |
| Posted by: Jon183 on 2017-12-15 05:32:33 Probably on Sunday or Monday ill look into it, I really need to look into circuit diagrams again, didn't pay much attention in class. | |
Posted by: Jon183 on 2017-12-24 02:51:37      | |
| Posted by: Jon183 on 2017-12-24 02:52:09 Forgot to clean the top board as seen in photo 4 down from the top. Cannot delete bottom duplicate photo for some odd reason. It was working when I plugged it in after who knows how long, then it powered down and I couldn't power it on again, its been bad ever since, even after recap. PSU is recapped (not two large 200V caps), board not really cleaned, the time to do that is now. | |
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