iici astec psu just died yesterday

[Jon183]

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.

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[BadGoldEagle]

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....

 

[techknight]

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. 

 

[IIfx]

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?

 

[Jon183]

I guess I can do a recap next week, even for the two large caps.

 

[Compgeke]

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.

 

[Jon183]

Ill put up a list of caps.




 


 




 


 




 


 




 


 




 


 




 


 




 


 




 


 




 


 




 


 




 


 




 

 

[Jon183]

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


 

 

[rickrob]

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


 

I 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.

 

[Jon183]

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.

 

[rickrob]

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

 

[Jon183]

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.

 

[rickrob]

Worked out great. Recapped the power supply and it started right up. My iici is 100 percent recapped, mobo and cache card too.

 

[Jon183]

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.

 

[Bolle]

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.

 

[Jon183]

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.

 

[Jon183]

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.

 

[Jon183]

 

[Jon183]

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.