In case you don't believe capacitors fail

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rubber_jonnie
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Re: In case you don't believe capacitors fail

Post by rubber_jonnie »

stephen_usher wrote: Wed Aug 12, 2020 10:09 am I wonder if he could reverse engineer a chip for me... It's one of the custom VLSI jobbies in a Sun 3/80 (Decode1) which has developed a fault on my machine. ;-)
You never know!
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Tomswork
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Re: In case you don't believe capacitors fail

Post by Tomswork »

@rubber_jonnie

Rifa side note many of the common one can be found under nf rather than uf .1 is 100nf .01 is 10nf

Like this 40yr psu
20200706_213810.jpg
20200706_213810.jpg (262.77 KiB) Viewed 2675 times
Tom
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rubber_jonnie
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Re: In case you don't believe capacitors fail

Post by rubber_jonnie »

Tomswork wrote: Wed Aug 12, 2020 3:17 pm @rubber_jonnie

Rifa side note many of the common one can be found under nf rather than uf .1 is 100nf .01 is 10nf

Like this 40yr psu

20200706_213810.jpg

Tom
Good to know. The failed RIFAs in my Mac actually had part numbers in easy to read format so I was able to look them up.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Dlfrsilver
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Re: In case you don't believe capacitors fail

Post by Dlfrsilver »

rubber_jonnie wrote: Tue Aug 11, 2020 11:48 pm One of the channels I frequent on YouTube is CuriousMarc.

It's a great channel with a lot of content across a number of subjects, and talks a lot about electronics and troubleshooting, something I am learning, and has helped me a lot.

There are a few videos on repairing more modern tech though, and there are some that go into replacing capacitors that have failed.

I particularly like this video, https://www.youtube.com/watch?v=Z4Kp8BDMzHY, because at about 9:30, he pulls apart a bad cap and a good cap, and the difference between the two is night and day.

So, in case you don't believe capacitors fail, have a look at this video and think about what might be going on, unseen, in your caps. It may surprise you.
Some ST PSU and some motherboard got some CrapXon capacitors brand.

The problem is that most users only rely on external aspect of capacitors, the proof is in the Pudding ! :lol:
Steve
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Re: In case you don't believe capacitors fail

Post by Steve »

It is absolutely ridiculous how many people (mainly on Facebook) will still claim there is nothing wrong with caps, especially in the Atari community. You always hear "it's not like Amiga with all their bad caps, Atari used good caps" lol. Yeah the mega cost saving company used the best caps... I've shown that the Atari caps don't leak or bulge, maybe because they're axial, maybe for other reasons I don't know, but you will never get a visual indication. But one day their computers will just die, they'll open their Ataris and cry "But the caps look fine!?!?" Then they will cry some more.
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exxos
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Re: In case you don't believe capacitors fail

Post by exxos »

Yeah I've given up with everyone outside of this forum. Pretty sad when I've actually got qualifications in electronics with almost 30 years in Atari's and fulltime work in electronics design / repair / diagnostics. Vs YouTube education and "looks fine" where the rest of the internet will agree type of facts. Real electronics is becoming a lost art.
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
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Re: In case you don't believe capacitors fail

Post by Dlfrsilver »

exxos wrote: Wed May 25, 2022 2:47 pm Yeah I've given up with everyone outside of this forum. Pretty sad when I've actually got qualifications in electronics with almost 30 years in Atari's and fulltime work in electronics design / repair / diagnostics. Vs YouTube education and "looks fine" where the rest of the internet will agree type of facts. Real electronics is becoming a lost art.
Absolutely :| Look, when i healed my Falcon 030, i not only did a good clean up, from "down the house to the top stair", but then i also did the maintenance on the PSU and the motherboard.

I discovered that the caps in the PSU just leaked, and when i posted on FB about the leak, many idiots came to me saying that what i show was some glue. The thing is that glue is hard and has to be removed with a screwdriver, while a real leak is simply liquid.

The other case i met was that some guys doing videos on Youtube just answered me "replacing capacitors is useless, this is a business = it's useless to replace them". Nevermind the crap quality of the original caps, and the fact that after changing the machine gets fine again.

Ahhh :/
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Re: In case you don't believe capacitors fail

Post by rubber_jonnie »

Dlfrsilver wrote: Thu May 26, 2022 11:24 pm
Absolutely :| Look, when i healed my Falcon 030, i not only did a good clean up, from "down the house to the top stair", but then i also did the maintenance on the PSU and the motherboard.

I discovered that the caps in the PSU just leaked, and when i posted on FB about the leak, many idiots came to me saying that what i show was some glue. The thing is that glue is hard and has to be removed with a screwdriver, while a real leak is simply liquid.

The other case i met was that some guys doing videos on Youtube just answered me "replacing capacitors is useless, this is a business = it's useless to replace them". Nevermind the crap quality of the original caps, and the fact that after changing the machine gets fine again.

Ahhh :/
I saw a similar post about leaky caps on a Falcon PSU (Might have been yours even) and the comments about glue were ridiculous. You only have to look to see that it's not glue but liquid, and as you say, funny how stuff works again after replacing them.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
atari030
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Re: In case you don't believe capacitors fail

Post by atari030 »

Some of the ST PSU's I recapped over the last two years were leaking pretty bad. STE and early FM, It was a PITA to clean up the boards. From the A1200's and A600's I've seen, they are atrocious. None look to be in good shape.
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Re: In case you don't believe capacitors fail

Post by rubber_jonnie »

atari030 wrote: Fri May 27, 2022 12:52 pm Some of the ST PSU's I recapped over the last two years were leaking pretty bad. STE and early FM, It was a PITA to clean up the boards. From the A1200's and A600's I've seen, they are atrocious. None look to be in good shape.
As it goes, whilst I have replaced PSU caps on my STs, none have ever been leaky, though a lot have failed and replacing them has brought the PSU back to life, I've never had a problem with caps on the mainboard.

The caps on my A1200 I caught just in time, and my Amstrad Alt-386 had just one on the mainboard, a little aluminium dustbin, that nearly killed it. A lot of the PSU caps were leaking in that too.

I also suspect my A5000 has some leaky caps which isn't helping!!
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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