How do you guys feel about recapping?

[+Stephen]

My thoughts on this have nothing to do with keeping items original.  It's to prevent people from wasting time and money for no reason, replacing items that are not broke and have little if any chance of breaking.  Light bulbs don't last forever, but do I go around and replace every light in my house that has 20 hours of use on it?

[Keatah]

I suppose it's pertinent to ask/determine the end goal of a preservation effort.

 

Consider an arbitrary vintage 486 system being preserved for the way it was, the manufacturing techniques, the weight, the time it takes to start up, the noises the drives make, and so on. Well, then, you better be sure you're sticking with all original parts. There'll be no SSD/Flash boot devices, there will be the original fans, the original CPU. Can't ever replace the CPU with FPGA or emulation. It would immediately fail the construction/manufacturing aspect. A future technician studying the faux FPGA CPU replacement in it would learn absolutely nothing about a socketed 168 pin 486 chip. What its construction was like, how it had gold-plated pins, how much heat it generated.. An so on

 

To take it further, if all the original cards and motherboard were removed and replaced with a NUC running PC-EM, it would fail even harder. Only a shell would remain, and the technician would learn even less.

 

Now consider a museum goer looking to see the system in operation. The case would be buttoned up, there could be an original motherboard in it, or it could be that NUC with PC-EM. The visitor wouldn't know. Either configuration would give said visitor a great experience in seeing how most software of the day looked and operated. The visitor interaction would be the same, indistinguishable except maybe like for booting. This is good enough for the vast majority of patrons. Perhaps even preferable because it would be 10x more reliable and the visitor could recreate the experience at home.

 

It's like that Space-a-Shuttle example. None of ships have operable engines, they were replaced with look-alike models. Many other under-the-skin modifications have been made - making the ships no longer flightworthy (not that that matters).

 

Most of the SR-71s have their wings band-sawed right where the engine nacelles meet the wings. Definitely not flying again. To a museum patron it's unknown. To a someone looking to do a structural test or study that exact spot, instant fail. Not that that would happen either. Just say'n.

[+-^CrossBow^-]

1 hour ago, Stephen said:

My thoughts on this have nothing to do with keeping items original.  It's to prevent people from wasting time and money for no reason, replacing items that are not broke and have little if any chance of breaking.  Light bulbs don't last forever, but do I go around and replace every light in my house that has 20 hours of use on it?

Actually yes I did this. One of the first things I did when LED bulbs started to become more affordable was swap out ever incandescent in the house with one. I think I've only had to replace one or two LED bulbs in nearly 10 years? Both of them were from my outside yard lights and actually were LED bulbs I found already in the house when we moved in.

 

I know what you meant but it was funny you mentioned light bulbs and I'm over here thinking... "Well yeah I actually kinda did..."

 

[+Stephen]

33 minutes ago, -^CrossBow^- said:

Actually yes I did this. One of the first things I did when LED bulbs started to become more affordable was swap out ever incandescent in the house with one. I think I've only had to replace one or two LED bulbs in nearly 10 years? Both of them were from my outside yard lights and actually were LED bulbs I found already in the house when we moved in.

 

I know what you meant but it was funny you mentioned light bulbs and I'm over here thinking... "Well yeah I actually kinda did..."

 

See what happens when I try to be a smart a$$?  Well played sir!

[Sir Guntz]

I'm stunned that there are seriously people who think it's okay to just leave leaky electrolytic capacitors on a board just because it's "original" and "authentic".

 

They are bog standard parts, they go bad, they have to be replaced when that happens. Either that or you can kiss the functionality of your console or computer goodbye.

 

Take the PC Engine Duo or the much more expensive TurboDuo (both the black looking model), or any Sega Game Gear even. Those systems have really bad capacitors. It's not a matter of if they will leak, it's when. Bad caps in these systems will leak and damage the circuit board they're attached to. On the PC Engine Duo, the most common symptom is weak or no audio, as most of the capacitors are for audio. On the Game Gear, it will just stop working when the caps get bad enough.

 

Computer hardware is no different from other machines we use every day that need servicing. Do you also think it's a smart idea to keep the original oil in your car and only use that because it's "original" and "authentic"? No, you replace the oil when it gets bad. Electrolytic capacitors are exactly the same. A standard part that will go bad eventually and they must be replaced, or your computer will stop working and likely deteriorate beyond repair.

[+DrVenkman]

I’m with @Stephen on this: if a cap is objectively damaged, swollen or leaking, or if it has failed short as determined by measurement then sure, replace it. But if a machine has no problems, leave stuff alone. Or worse, some n00b to Atari collecting buys a busted system and the first thing they do is recap the thing and is then surprised when it still doesn’t work? Drives me freaking crazy. These folks come to retro stuff after growing up with crap consumer electronics from the late 90’s trough early Aughts when cap plague was a thing; it doesn’t even occur to them that it was an era-specific problem. So their first post here is, “I bought this system and recapped it. It still doesn’t work. HELP!” Well, shit dude. You spent 60 minutes and ham-fistedly replaced a bunch of through-hole stuff you barely know how to work on for no reason.

 

Do a little research BEFORE you do the surgery! Get the Field Service Manual and multimeter and start working through the possibilities. “Just recap it!” is NEVER the right approach unless you can already see some damage. Capacitors aren’t magic and they serve specific electronic purposes. On a system like an Atari, especially, there are very few parts of the machine where a bad-but-not-dead cap could stop the machine from running.  

[Turbo-Torch]

11 hours ago, Sir Guntz said:

I'm stunned that there are seriously people who think it's okay to just leave leaky electrolytic capacitors on a board just because it's "original" and "authentic".

 

I'd suspect those people are on the extreme end of the autistic spectrum, not much different than someone who eats foam from couch cushions or has 100 cats living in their house.

There's probably a few people in this world that would like to see an L88 Corvette with the original engine oil that turned acidic 50 years ago, along with the original battery that's leaked and corroded everything surrounding it.  Fortunately, those people don't count and wouldn't be able to afford the steering wheel off such a car.

 

 

[Turbo-Torch]

On 3/11/2021 at 2:30 AM, Keatah said:

I once spoke with someone that was maintaining computers for a museum and the issue of batteries came up. I was horrified to see some boards with those leaky vartabombs and even super old coin cells. They refused to change them out. They cited authenticity. And, get this, authenticity of its future destiny. They said if it's destined to corrode in that area then that is what MUST take place. We won't interrupt the aging process.

 

 

Really?  So what's the name of this museum?  Or is it a secret that you can't let out?

Edited March 20, 2021 by Turbo-Torch

[Sir Guntz]

3 hours ago, DrVenkman said:

I’m with @Stephen on this: if a cap is objectively damaged, swollen or leaking, or if it has failed short as determined by measurement then sure, replace it. But if a machine has no problems, leave stuff alone. Or worse, some n00b to Atari collecting buys a busted system and the first thing they do is recap the thing and is then surprised when it still doesn’t work? Drives me freaking crazy. These folks come to retro stuff after growing up with crap consumer electronics from the late 90’s trough early Aughts when cap plague was a thing; it doesn’t even occur to them that it was an era-specific problem. So their first post here is, “I bought this system and recapped it. It still doesn’t work. HELP!” Well, shit dude. You spent 60 minutes and ham-fistedly replaced a bunch of through-hole stuff you barely know how to work on for no reason.

 

Do a little research BEFORE you do the surgery! Get the Field Service Manual and multimeter and start working through the possibilities. “Just recap it!” is NEVER the right approach unless you can already see some damage. Capacitors aren’t magic and they serve specific electronic purposes. On a system like an Atari, especially, there are very few parts of the machine where a bad-but-not-dead cap could stop the machine from running.  

Some game consoles and home computers are known to have bad capacitors though. As in, ALL units of a particular make and model have bad caps and will stop working.

 

Some examples:

 

PC Engine Duo / TurboDuo (not R or RX versions)

Sega Game Gear

LaserActive PAC modules (NEC and Sega)

Most 68k Macintosh computers (Compacts, LCs, etc)

eMac G4

iMac G5

(probably many other G3, G4 and G5 systems too)

 

In those cases, the failure and inevitable damage is practically guaranteed. Every single PC Engine Duo has bad capacitors. The leakage from those caps damages the board and always results in weak or missing audio. This isn't just a few units, it's all of them.

 

So, yes there are some computers/consoles that aren't known for bad caps, but there are certainly lots that do.

Edited March 20, 2021 by Sir Guntz

[+DrVenkman]

8 minutes ago, Sir Guntz said:

Some game consoles and home computers are known to have bad capacitors though. As in, ALL units of a particular make and model have bad caps and will stop working.

 

Some examples:

 

PC Engine Duo / TurboDuo (not R or RX versions)

Sega Game Gear

LaserActive PAC modules (NEC and Sega)

Most 68k Macintosh computers (Compacts, LCs, etc)

eMac G4

iMac G5

(probably many other G3, G4 and G5 systems too)

Did you actually read my post? I specifically referred to the era of capacitor plague - pretty much every machine you list is from that era. Atari machines, especially 8-bit stuff, predates that era by anywhere from 5 - 20 years. I've had exactly ONE bad electrolytic in an Atari 8-bit computer, and that was because I accidentally ran too much current through it while I was doing some mod work - it was a teeny 10uF cap that split wide open and started leaking. Utterly impossibly to miss visually. I've found a relative handful of polystyrene caps going (not gone!) bad in two different 4-switch Atari VCS consoles but they still worked (just had fuzzy video and/or audio issues). That's it. I own or have owned nearly two dozen Atari machines and a handful of other 8-bit era stuff and the caps in them have been fine. 

 

tl;dr: if it's not broke, don't "fix" it. 

[+Stephen]

Because I am tired of mis-information and second or third hand repeated anecdotes, I spent some time this evening and actually took some measurements.  This is from an Atari 800 - very early 1979 power board.  Covered in dirt, one main cap sort of looks a little puffy.  Hasn't been powered up in the 10 years since I got it non-working from Ebay.

 

I took out all 8 electrolytic caps.  To measure them, I used my DATS V3 hardware.  It takes "high-resolution impedance response measurements with 30,000 data points (1 Hz to 20,000 Hz)".  As a capacitance meter it will measure all of a capacitors electrical characteristics including capacitance, equivalent series resistance, Q, and even loss angle. DATS V3 is capable of accurately measure capacitance from 0.002 uF to 10,000 uF.

 

I am enclosing all measured data.  The part #, the rated value, and how it measured.  TL/DR version - all 8 capacitors were WELL within spec, measuring a few percent over rated micro-farads.  ESR was perfectly acceptable.

C201 is rated 470uF 16V it measures 503.3 uF
f = 120 Hz,     ESR = 0.5509 Ohms,     DF =  20.6 %, Q = 4.854,   DELTA = 11.64 deg
f =  1k Hz,     ESR = 0.4669 Ohms,     DF = 187.2 %, Q = 0.534,   DELTA =  61.9 deg
f = 10k Hz,     ESR = 0.125 Ohms,     DF =  1150 %, Q = 0.08698, DELTA = 85.03 deg

C202 is rated 470uF 16V it measures 507.1 uF
f = 120 Hz,     ESR = 0.5301 Ohms,     DF = 20.16 %, Q =  4.96,   DELTA =  11.4 deg
f =  1k Hz,     ESR = 0.4662 Ohms,     DF = 191.1 %, Q = 0.5233,  DELTA = 62.38 deg
f = 10k Hz,     ESR = 0.1299 Ohms,     DF =  1437 %, Q = 0.06958, DELTA = 86.02 deg

C204 is rated 2200uF 16V it measures 2302 uF
f = 120 Hz,     ESR = 0.3748 Ohms,     DF = 77.12 %, Q = 1.297,   DELTA = 37.64 deg
f =  1k Hz,     ESR = 0.1958 Ohms,     DF =   545 %, Q = 0.1835,  DELTA =  79.6 deg
f = 10k Hz,     ESR = 0.08689 Ohms, DF =  4216 %, Q = 0.02372, DELTA = 88.64 deg

C205 is rated 2200uF 16V it measures 2405 uF
f = 120 Hz,     ESR = 0.3836 Ohms,     DF = 84.67 %, Q = 1.181,   DELTA = 40.25 deg
f =  1k Hz,     ESR = 0.2023 Ohms,     DF = 565.7 %, Q = 0.1768,  DELTA = 79.98 deg
f = 10k Hz,     ESR = 0.096 Ohms,     DF =  3523 %, Q = 0.02839, DELTA = 88.37 deg

C207 is rated 4700uF 25V 85C it measures 5110 uF
f = 120 Hz,     ESR = 0.219 Ohms,     DF = 142.4 %, Q = 0.7024,  DELTA = 54.92 deg
f =  1k Hz,     ESR = 0.094 Ohms,     DF = 842.6 %, Q = 0.1187,  DELTA = 83.23 deg
f = 10k Hz,     ESR = 0.0404 Ohms,     DF =  5593 %, Q = 0.01788, DELTA = 88.98 deg

C208 is rated 4700uF 25V 85C it measures 4993 uF
f = 120 Hz,     ESR = 0.2222 Ohms,     DF = 137.9 %, Q = 0.725,   DELTA = 54.06 deg
f =  1k Hz,     ESR = 0.09402 Ohms, DF =   738 %, Q = 0.1355,  DELTA = 82.28 deg
f = 10k Hz,     ESR = 0.03889 Ohms, DF =  5159 %, Q = 0.01938, DELTA = 88.89 deg

C210 is rated 10uF 16V it measures 11.18 uF
f = 120 Hz,     ESR =  11.4 Ohms,     DF = 9.768 %, Q = 10.24,   DELTA = 5.579 deg
f =  1k Hz,     ESR = 3.212 Ohms,     DF = 20.46 %, Q = 4.888,   DELTA = 11.56 deg
f = 10k Hz,     ESR = 1.954 Ohms,     DF = 119.9 %, Q = 0.8337,  DELTA = 50.18 deg

C211 is rated 10uF 16V it measures 11.72 uF
f = 120 Hz,     ESR = 9.632 Ohms,     DF = 8.673 %, Q = 11.53,   DELTA = 4.957 deg
f =  1k Hz,     ESR = 3.144 Ohms,     DF = 21.34 %, Q = 4.686,   DELTA = 12.05 deg
f = 10k Hz,     ESR = 1.963 Ohms,     DF = 127.5 %, Q = 0.7846,  DELTA = 51.88 deg

[_The Doctor__]

So everyone can understand

 

https://circuitdigest.com/tutorial/understanding-esr-and-esl-in-capacitors

 

the only time an ever so slightly higher ESR may be desirable is in decoupling caps at certain frequecies

 

https://www.avnet.com/wps/portal/abacus/resources/article/understanding-esr-in-electrolytic-capacitors/

[carlsson]

On 3/20/2021 at 3:32 PM, DrVenkman said:

if a cap is objectively damaged, swollen or leaking, or if it has failed short as determined by measurement then sure, replace it.

In any case, it means we should open up at least the systems known to be in danger no less than once a year and inspect if something is looking funny. If everything still seems alright, just close the system and let it be for another year. Like a yearly doctor's visit. The comparison with the light bulb is skewed by the fact that usually you'll see right away when the bulb goes, and besides most light bulbs don't explode in such way that the bulb socket or the entire lamp gets damaged.

 

But yeah, it is good news that all caps from a 1979 Atari still rate properly. It matches what I speculated about earlier, that continuous optimization and price cutting probably means newer capacitors are worse than the older ones. We know about the plague in the very end of the 90's and early 2000's due to the stolen formula, but already earlier in the 90's before the formula was stolen and regardless of the PC Chips fakes, at least some cut corners which caused known problems today. If it wasn't so much trouble desoldering and measuring caps, I'm sure more people could do that to put together a database of which caps are more likely to go bad than others.

[juansolo]

On 3/22/2021 at 5:36 PM, carlsson said:

But yeah, it is good news that all caps from a 1979 Atari still rate properly.

They didn't in one I RGB modded last week... So you can't really take that as all caps in 1979 are still good today.

[+Stephen]

2 hours ago, juansolo said:

They didn't in one I RGB modded last week... So you can't really take that as all caps in 1979 are still good today.

What machine and what caps?  Were they physically leaking or damaged?  If not, please post measurements like I did showing that they were out of spec.  If they were leaking, please post pics.

[+Stephen]

Here's another piece of non-anecdotal evidence.  I spent a few days replacing all the lights in my Sansui 7070 receiver from 1976.  I bought it in early 2015.  It gets used 7 days a week for 12 to 18 hours a day.  Guess what I did not do?  Recap the damn thing.  The bias current for both channels was dead on spec and the DC output was -6mV on the left channel and 10mV on the right channel.  Also in spec.  Just to make it perfect, I was able to adjust both channels to 0.4mV.

 

It is rated for 60 watts RMS.  It outputs 72 with zero clipping (into 8-ohm load block using oscilloscope to verify clean output).  It will cleanly amplify signals past 70kHz.  The three band equalizer on it is in spec regarding frequency and levels.

 

But sure - I should have definitely recapped it, because of the 1976 build date.

[juansolo]

It was last week, a couple were out, one read nowhere close, there was no leaking. It varies from machine to machine. A lot of machines pass through our hands, some are just fine, some are not. But go on your own experience if that works for you, just understand that your experience does not equal everyone's experience.

 

Other than that, I'm not about to get into a pissing contest with someone online about it because frankly, life is too short.

[+eebuckeye]

Recaps need to happen at least for some systems already mentioned.  Amiga 1200, Turbo Duo, Turbo Express and others.  I had cap leakage on my Turbo Express and was very lucky that a cap replacement and minor repair fixed it.  Keeping original is crazy in my opinion at least for the systems that are known for bad caps.  One of the first questions will be 'has it been recapped'.

[carlsson]

I found a sponsored article about testing capacitors in circuit using an ESR meter. Does anyone have experience of that, and how reliable is it in practice?

https://www.yamanelectronics.com/test-capacitor-without-desoldering/

[juansolo]

19 hours ago, carlsson said:

I found a sponsored article about testing capacitors in circuit using an ESR meter. Does anyone have experience of that, and how reliable is it in practice?

https://www.yamanelectronics.com/test-capacitor-without-desoldering/

You can't test capacitance in circuit. You can tell it's not shorting, but that's about it. To test them you really have to pull them. If you're pulling them, you may as well swap them for new ones as half the job is already done...

[damanloox]

Electrolytic capacitors degrade over time ("by design/nature"). Sometimes they degrade to the point of spilling electrolyte all over the place. It's not whether somebody want's to keep an item "original" or not - it's about keeping it working. I'm pretty sure no collector/historian would be happy having rare machine that has half ot the traces "removed" by leaking capacitors. The "keeping it as original" argument makes absolutely no sense unless somebody wanted to keep a shell only. 

And yes - I do replace caps in my ageing machines. Purely because some have very little use and I'm not going to take them apart every now and then just to visually inspect capacitors (and "visual inspection" is no guarantee either and testing in circuit is like groundhog forecast). I don't believe in "unopened collector's value". Somebody who allows the piece of history to rot in leaking electrolyte is certainly not a collector in my opinion.

[santoscork]

Recapping is important. Electrolytic capacitors, similar to toner or car tires, are consumables meant to wear out over time. To maintain the functionality of your original Atari hardware, replacing these capacitors is necessary to avoid potential issues. This is not a matter of opinion but rather a factual requirement. While some may argue that replacing capacitors alters the machine’s originality, it’s a subjective viewpoint. As a collector of vintage hardware, finding time for these maintenance tasks is often a challenge. Fortunately, Atari 8-bit computers and video game consoles have relatively few capacitors to replace. However, dealing with original power supplies, which are typically epoxy-sealed, poses a real challenge. I’ve resorted to new third-party power supplies for my 800XL and 2600s, ensuring reliable power delivery, which is important for proper functioning.

 

Maintaining vintage hardware and keeping them running in spec is, in my opinion, one of the pieces to this hobby that adds a unique appreciation for the hardware. It offers a hands-on learning experience about the inner workings of these classic machines, which enhances our understanding and appreciation for their technology and historical significance.

[CaptainBreakout]

Interesting that this response came out of nowhere from a few years gap, and yet I find it so succinct and well-written, and I agree with it. Nice.

 

I'm surprised no one has brought up batteries as an analogy.  Everyone here knows batteries will leak and cause all kinds of damage to battery compartments, or worse... The PCBs that were unlucky enough to be designed with them in place.

 

I don't think anyone who's into vintage toys, for example, would suggest keeping the 1970 factory Everreadys in the battery compartment of a toy robot for authenticity.

 

The CD-i I can see across the room has such a component... And I've worked on a lot of pinball games that have malfunctioned as a result of being stored with batteries on the motherboard.  Sometimes these batteries are manufactured into the game (Gottlieb, I'm looking at you).  No one is happy when they discover that their pinball won't work anymore even though they've kept it wrapped up in storage untouched for three decades, simply due to battery corrosion.

 

Capacitors are very much like this, but on a longer time line.

 

Someday I'm looking forward to a new technology... A component that will replace the capacitor with something that will truly last forever. That would be nice. A little like an LED versus an incandescent bulb.

 

It's a bit lame thinking when I replace capacitors for something that it may be that the ones I installed will need to be replaced again in 30 years.

 

Still this hobby is a lot like classic cars. 

 

So in the sense I ask you... What's more impressive/desirable?... A Model-T that's totally original... with brittle cast wheel bearings and all kinds of problems resulting from 100year-old parts and decay even from being stored in the best of conditions... Or one that's reasonably modernized and ready to take you down the street?

 

Edited January 30 by CaptainBreakout

[Video]

My thoughts on recapping, I've got no issue if it is needed. If a cap goes out, your device can quit working, sometimes disasterously so. However, that's if needed, not just "because I can" atari 2600 is a really reliable machine and if you regularly use it, it shouldn't need recapped. Most peoples problem with it is "I got out of playing for years or decades, and went back to it after the caps dried out from lack of use" assuming someone didn't stop playing bitd because a cap blew and back then it wasn't possible to Google fixes.

 

I don't care for modding, but hey, its your toy, not mine so that is up to you. Recapping is about preservation, not modding, to get as long a life out of a product as possible, so that's cool if you can. Buying someone else's thing is just inheriting someone else's problem, especially with a 40+ year old piece of hardware, so not necessarily a viable option. And as seen with 2600+ even new may not be. I'd love a 100% replacement for my aged 2600, sure, but its going to be a future thing, if ever. Recapping is still a last resort for me as I lack experience/skill to do it, but I'd try if I had to, because I love my 2600, but like I said, last resort, I'd risk serious chance of doing further damage or destroying it doing it myself. Luckily my childhood Vader still works fine, knock on wood.