Dave Haynie and SMD caps

matthey · 10 April 2011, 20:42

Dave Haynie is having a garage sell...

http://www.amiga.org/forums/showthread.php?t=57327
http://shop.ebay.com/?_from=R40&_trk...All-Categories

One of the items he is selling is a revision 2 CD32 with the caps leaking...

http://cgi.ebay.com/Haynies-Garage-C...item1e62d71a68

He mentions...

"I think it's probably seen better days, there seems to be some kind of corrosion around the capacitors, which is weird, since those are aluminum air caps, not something filled with a dielectric goo. But there it is."

The pics look like leaking SMD caps with dust attached to me. This is just another common example of crappy leaking SMD caps from the research I have been doing. I'm about to do a cap and restoration job myself for a 4000, 4000T (amber rev 2 motherboard like the rev 2 CD32) and a CD32 and I really don't like the idea of using crap parts. My 3000s and 3000T with thru holes work fine with no leaking caps (batteries removed). It looks like the only options to avoid the SMD electrolytic caps are to use thru hole electrolytic caps or tantalum caps. Electrolytic thru hole caps look like a good compromise for less leaking/longevity (vs SMD), safety (vs tantalum) and price (vs tantalum). The availability of the thru hole is good for even the smaller sizes where SMD is used on Amigas. Is there any problems or disadvantages with installing thru hole electrolytic capacitors (bending legs and laying across pads) where there is room (everywhere!)? Does this sound reasonable? Has anyone done this also? Would a professional electronic service person frown on me if I asked him to install these?

My buster socket is warped and bulging out and my boards disappear after warmed up on my 4000T (yes, socketed on rev 2) so I want to replace that too. Will this 84 pin SMD plcc socket work?...

http://search.digikey.com/scripts/Dk...me=3M8421B1-ND

Thanks.

P.S. Dave put a NYX AAA motherboard board up too 8-) with battery still intact (Doh!)...

http://cgi.ebay.com/Haynies-Garage-N...item1e62da18bf

Battlstarcanada · 10 April 2011, 21:47

I'm "watching" the AAA prototype board just to see how much it goes for!

orange · 10 April 2011, 22:02

yes, I've seen someone using through-hole tantalum in aorg photo gallery (iirc, A4000 audio caps).
it looks professional, dunno if there are some problems.

matthey · 10 April 2011, 23:59

Quote:

Originally Posted by Battlstarcanada

I'm "watching" the AAA prototype board just to see how much it goes for!

I would expect to see $2000-$4000 U.S. because of the documentation and Dave Haynie giving 1/2 to charity. Maybe the same price range as a working 3000+? Non functional and missing the AAA chips hurts a lot. I think there will be a lot of "watchers" though.

Quote:

Originally Posted by orange

yes, I've seen someone using through-hole tantalum in aorg photo gallery (iirc, A4000 audio caps).
it looks professional, dunno if there are some problems.

I've seen a few tantalum upgrades and I would say the explosion risk is probably overrated if only replacing the smaller caps and non audio caps. I was not planning on doing the caps in tantalum though. The audio caps see negative voltage and should be bi (non) polar electrolytics from what I understand. I was actually wanting to use thru hole electrolytic caps for all replacements and bi-polar electrolytics for the troublesome audio caps. These 22uf 16V bi-polar eloctrolytics look good at a reasonable price...

http://search.digikey.com/scripts/Dk...&name=P1164-ND

Zetr0 · 11 April 2011, 00:23

@matthey

They look great to me, something I should do on my A4k!

jaycee · 11 April 2011, 00:31

Tants are dreadful. Ugh. They have a habit of failing SHORT with age and exploding.

Panasonic capacitors are excellent. Their "FC" series are also great.

matthey · 11 April 2011, 01:33

Quote:

Originally Posted by jaycee

Tants are dreadful. Ugh. They have a habit of failing SHORT with age and exploding.

Tantalum caps die and explode. SMD electrolytics leak. Why isn't there more people that solder thru hole electrolytics on SMD pads? It seems like the logical solution to me. I have yet to hear from anyone that thinks it is a bad idea. Hmmm

.

jaycee · 11 April 2011, 01:39

Quote:

Originally Posted by matthey

Tantalum caps die and explode. SMD electrolytics leak. Why isn't there more people that solder thru hole electrolytics on SMD pads? It seems like the logical solution to me. I have yet to hear from anyone that thinks it is a bad idea. Hmmm

.

I've used through hole caps on SMD pads myself plenty of times. The SMD electrolytics are made exactly the same way, they just dont have plastic covers and they have flat leads which are fed through a plastic base and bent flat.

The Amigas used early generation SMD parts, so I guess design flaws in those parts have long since been corrected. Capacitors have a finite life span anyway, and many Amigas have long exceeded that lifespan.

matthey · 11 April 2011, 03:17

Quote:

Originally Posted by jaycee

... The SMD electrolytics are made exactly the same way...

They should have been made the same way back then but the SMD caps leaked and the non SMD caps didn't.

Quote:

Originally Posted by jaycee

The Amigas used early generation SMD parts, so I guess design flaws in those parts have long since been corrected. Capacitors have a finite life span anyway, and many Amigas have long exceeded that lifespan.

Yea, it could have been that early SMD caps were defective. We won't know if later ones were for awhile. It looks like the new SMD caps are the same design which is what worries me. Another potential problem is that most electronics makers plan on obsolescence in 5 years or less so why would cap manufacturers change the design? I'm not so worried about the caps failing as leaking. Well, thanks for your opinion. That's +1 who thinks modern SMD=thru hole for cap leak resistance. Maybe I should have started a poll. Any one else with an opinion?

Damion · 11 April 2011, 05:59

I think it's more a matter of quality than SMD vs thru-hole. The SMD Panasonics used on (at least) some earlier A4000's usually don't leak, but the cheapies do. (I've yet to see an A600 or Commodore A1200 board with out at least some evidence of leakage.) The thru-hole caps used in the earlier Amigas were generally good quality (Elna, Shoei, Nichicon). I've yet to have an issue with those, but I've seen plenty of cheap thru-hole caps leak, explode, or otherwise fail.

My opinion - keep things original, stick with a quality Japanese SMD cap (Panasonic, Nichicon, UCC) and they will last a very long time.

Hewitson · 11 April 2011, 06:29

Quote:

Originally Posted by matthey

Tantalum caps die and explode. SMD electrolytics leak. Why isn't there more people that solder thru hole electrolytics on SMD pads? It seems like the logical solution to me. I have yet to hear from anyone that thinks it is a bad idea. Hmmm

.

I think it's a bad idea, you could knock the cap and rip the pad off the board. Unlikely, but I have seen it happen.

orange · 11 April 2011, 08:01

@Hewitson

yeah, but that could also happen with SMD. though less likely.

Hewitson · 11 April 2011, 10:19

I don't agree. A properly soldered SMD resistor/capacitor has an incredibly strong mechanical attachment to the board.

Loedown · 11 April 2011, 11:33

Quote:

Originally Posted by Hewitson

I don't agree. A properly soldered SMD resistor/capacitor has an incredibly strong mechanical attachment to the board.

Problems usually arise if you use a through hole part and too much heat into the pad. SMD parts do have a very secure mechanical strength to the board but this can also be their weakness, as when the boards are manufactured, if the reflow curve isn't correct for the board it puts too much mechanical stress on mostly the 1206 / 805 / 603 / 402 parts and this can cause micro cracking within the parts themselves. Flexing the board after it's been reflowed and cooled causes similar sorts of problems. One board I used to test had a string of capacitors along one edge and naturally it was snap pressed into a housing, stupid design and multiple field failures.

Paul_s · 12 April 2011, 08:13

Quote:

Originally Posted by matthey

I would expect to see $2000-$4000 U.S. because of the documentation and Dave Haynie giving 1/2 to charity. Maybe the same price range as a working 3000+? Non functional and missing the AAA chips hurts a lot. I think there will be a lot of "watchers" though.

It's the same board as shown on amiga-hardware.com. Albeit with a bit less battery acid leakage!

To quote DH;

"This was the first functional AAA board, and also the first to die. The death was in part purely accidental, and in part a bit of negligence. First to blame is me. Back in those days, you needed +12V for Flash memory, so I had this going to the Flash SIMM modules. Sadly, rather than protect the +12V signal with grounds on either side, or some-such, I pretty much ignored the signal neighbors. This is not the best decision, since a +12V shorted to a normal TTL-level input can destory that input.

Second problem was the ROM SIMM itself. The PCB guys messed up just slightly here, so the SIMM didn't fit tightly in the connector, but could slide left or right a bit. Which allowed adjacent pins to occasionally short out. Fortunately, I noticed this early on, and did not allow a short to occur. Unfortunately, some of the chip designers didn't know about this, and one day tried to start up the board when I wasn't around. The result was a +12V short to data-line D5, killing much of the system. Well, hey, these things happen, and we had two other boards. Those boards went with some of the top chip guys on the AAA project. Far as I know, at least one of those was still functional, or at least as functional as these things got."

pcut · 13 April 2011, 11:42

There is a load of old Amiga and Commodore prototype hardware for sale from an ex Commodore employee on ebay.

http://shop.ebay.com/?_from=R40&_trk...All-Categories

orange · 13 April 2011, 17:07

@pcut
haven't been paying attention?

fitzsteve · 13 April 2011, 17:10

Quote:

Originally Posted by orange

@pcut
haven't been paying attention?

I imagine a Mod moved the post here - probably TCD

TCD · 13 April 2011, 19:58

Quote:

Originally Posted by fitzsteve

I imagine a Mod moved the post here - probably TCD

Guilty

UberFreak · 14 April 2011, 14:36

@matthey

I've replaced leaking SMD caps with mini thru-hole ones on A1200, A4000, A600 & CD32.
No problems at all, just make sure to cut the legs short enough to lower stress to the pads.

10 April 2011, 20:42	#1
matthey Banned Join Date: Jan 2010 Location: Kansas Posts: 1,284	Dave Haynie and SMD caps Dave Haynie is having a garage sell... http://www.amiga.org/forums/showthread.php?t=57327 http://shop.ebay.com/?_from=R40&_trk...All-Categories One of the items he is selling is a revision 2 CD32 with the caps leaking... http://cgi.ebay.com/Haynies-Garage-C...item1e62d71a68 He mentions... "I think it's probably seen better days, there seems to be some kind of corrosion around the capacitors, which is weird, since those are aluminum air caps, not something filled with a dielectric goo. But there it is." The pics look like leaking SMD caps with dust attached to me. This is just another common example of crappy leaking SMD caps from the research I have been doing. I'm about to do a cap and restoration job myself for a 4000, 4000T (amber rev 2 motherboard like the rev 2 CD32) and a CD32 and I really don't like the idea of using crap parts. My 3000s and 3000T with thru holes work fine with no leaking caps (batteries removed). It looks like the only options to avoid the SMD electrolytic caps are to use thru hole electrolytic caps or tantalum caps. Electrolytic thru hole caps look like a good compromise for less leaking/longevity (vs SMD), safety (vs tantalum) and price (vs tantalum). The availability of the thru hole is good for even the smaller sizes where SMD is used on Amigas. Is there any problems or disadvantages with installing thru hole electrolytic capacitors (bending legs and laying across pads) where there is room (everywhere!)? Does this sound reasonable? Has anyone done this also? Would a professional electronic service person frown on me if I asked him to install these? My buster socket is warped and bulging out and my boards disappear after warmed up on my 4000T (yes, socketed on rev 2) so I want to replace that too. Will this 84 pin SMD plcc socket work?... http://search.digikey.com/scripts/Dk...me=3M8421B1-ND Thanks. P.S. Dave put a NYX AAA motherboard board up too 8-) with battery still intact (Doh!)... http://cgi.ebay.com/Haynies-Garage-N...item1e62da18bf Last edited by matthey; 10 April 2011 at 21:42.

13 April 2011, 11:42	#16
pcut Registered User Join Date: Aug 2009 Location: Liverpool Posts: 26	Prototype amiga/commodore hardware on ebay There is a load of old Amiga and Commodore prototype hardware for sale from an ex Commodore employee on ebay. http://shop.ebay.com/?_from=R40&_trk...All-Categories

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10 April 2011, 21:47	#2
Battlstarcanada www.battlestarcanada.com Join Date: Apr 2011 Location: Durham, NC USA Posts: 10	I'm "watching" the AAA prototype board just to see how much it goes for!

10 April 2011, 22:02	#3
orange Registered User Join Date: Apr 2007 Location: Belgrade Posts: 567	yes, I've seen someone using through-hole tantalum in aorg photo gallery (iirc, A4000 audio caps). it looks professional, dunno if there are some problems.

11 April 2011, 00:23	#5
Zetr0 Ya' like it Retr0? Join Date: Jul 2005 Location: United Kingdom Age: 49 Posts: 9,768	@matthey They look great to me, something I should do on my A4k!

11 April 2011, 00:31	#6
jaycee Registered User Join Date: Sep 2006 Location: Norwich, UK Posts: 57	Tants are dreadful. Ugh. They have a habit of failing SHORT with age and exploding. Panasonic capacitors are excellent. Their "FC" series are also great.

11 April 2011, 05:59	#10
Damion Registered User Join Date: Mar 2008 Location: US Posts: 315	I think it's more a matter of quality than SMD vs thru-hole. The SMD Panasonics used on (at least) some earlier A4000's usually don't leak, but the cheapies do. (I've yet to see an A600 or Commodore A1200 board with out at least some evidence of leakage.) The thru-hole caps used in the earlier Amigas were generally good quality (Elna, Shoei, Nichicon). I've yet to have an issue with those, but I've seen plenty of cheap thru-hole caps leak, explode, or otherwise fail. My opinion - keep things original, stick with a quality Japanese SMD cap (Panasonic, Nichicon, UCC) and they will last a very long time.

11 April 2011, 08:01	#12
orange Registered User Join Date: Apr 2007 Location: Belgrade Posts: 567	@Hewitson yeah, but that could also happen with SMD. though less likely.

11 April 2011, 10:19	#13
Hewitson Registered User Join Date: Feb 2007 Location: Melbourne, Australia Age: 41 Posts: 3,772	I don't agree. A properly soldered SMD resistor/capacitor has an incredibly strong mechanical attachment to the board.

13 April 2011, 17:07	#17
orange Registered User Join Date: Apr 2007 Location: Belgrade Posts: 567	@pcut haven't been paying attention?

14 April 2011, 14:36	#20
UberFreak Registered User Join Date: Sep 2009 Location: the world Posts: 439	@matthey I've replaced leaking SMD caps with mini thru-hole ones on A1200, A4000, A600 & CD32. No problems at all, just make sure to cut the legs short enough to lower stress to the pads.

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