TI-99/4A EU PAL 1981 V2 - New electrolytic capacitors

[Sid1968]

11 minutes ago, Schmitzi said:

 

What is an ESR ?

 

 

https://www.elektroniknet.de/elektronik/distribution/was-versteht-man-bei-kondensatoren-unter-esr-135202.html

[humeur]

ESR it is a device that allows you to check the capacitors without desoldering them, which measures the internal resistance of the capacitor, and then you compare the value with reference values.

you know right away if a capacitor is normal.

 

Jean Louis

[humeur]

2 hours ago, Sid1968 said:

As I wrote in my first post: "Some people think that they do not need an Elko-Change until a device gets problems. Make your on decision."

I did not waited for a 38 year old component that only costs a few cents to break and maybe break components that are difficult to get or even no longer available!

 

And if you look at the result, it's worth seeing, isn't it? I also mean that on the LCD screen.

 

But of course I prefer to respect your decision to wait until your device gets problems. I wish you that your TI-99/4A will live for a very long time. Conversely, please respect that this thread is about successfully performing the elkochange on the TI-99/4A. Something that goes without saying in the commodore scene.

You cannot compare the manufacture of capacitors from the 1980s to those of today.
I have not had an answer how many have you find bad in the ti99, and the control of these has been done before changing them.
I only change if it's useful

[Sid1968]

12 minutes ago, humeur said:

ESR it is a device that allows you to check the capacitors without desoldering them, which measures the internal resistance of the capacitor, and then you compare the value with reference values.

you know right away if a capacitor is normal.

 

Jean Louis

The ESR is not a device, its the "equivalent series resistance" of a capacitor, that we call in german "Ersatzserienwiderstand".

Edited April 24, 2020 by Sid1968

[humeur]

5 minutes ago, Sid1968 said:

ESR is not the device, its the "Equivalent series resistance", that we call in german "Ersatzserienwiderstand".

it's playing on the word everyone speaks ESR.

 

By cons your idea to change the 78M12 regulator by these small switching power supply module is excellent, performance being less efficient.

 

Jean Louis

Edited April 24, 2020 by humeur

[Sid1968]

Just now, humeur said:

it's playing on the word everyone speaks ESR.

 

Maybe everyone you know. In Germany, we usually name things with their correct names or abbreviations. I think that is also so common in English-speaking countries.

[humeur]

2 minutes ago, Sid1968 said:

Maybe everyone you know. In Germany, we usually name things with their correct names or abbreviations. I think that is also so common in English-speaking countries.

I am in France and when you say ESR people understand that it is the measure and not the definition.

 

[Sid1968]

I wish you a happy day.

[humeur]

Just now, Sid1968 said:

I wish you a happy day.

Thank you for such a good day and take care of yourself.

 

Jean louis

[Sid1968]

Hi Guys,
the method proposed by "humeur" to check the function of an electrolytic capacitor by measuring the ESR is well suited for this.
If you want to check your TI-99/4A for damaged electrolytic capacitors, you can use this method.

But why is this not necessary when changing the elkos completely?

If you want to get detailed information about an electrolytic capacitor, please have a look at the wiki here: https://en.wikipedia.org/wiki/Electrolytic_capacitor

Have a look under "Reliability (failure rate)" and "Lifetime". The "Early Failures" and the "Wearout Fairlures" are problematic in the Life of an elektolytic capacitor.

The "Wearout Fairlures" increase exponentially with age!!! This is what it is all about changing the complete elkos.

 

A direct failure of an electrolytic capacitor cannot be predicted exactly. You have to estimate it based on several factors. But if I have a 38-year-old device in front of me,

as in the example above, the probability of failure is quite high, because of the exponentially increasing probability of"Wearout Fairlures". Of course, the device could theoretically

continue to work flawlessly for another 38 years ... but it is that probably???

 

The overall question is not whether an electrolytic capacitor needs to be changed, but when.

 

The complete exchange of the elkos now, even if everyone should still work now, has the advantage that, so far no other component has been damaged by a defective electrolytic capacitor,

the new elkos are relatively cheap, the time required is limited to a few hours and you have a refreshed system afterwards. With the new electrolytic capacitors, there is no need to worry

about the next 20-30 years or more, if you use the device in a normal way.

Since a defective electrolytic capacitor can also damage other components in the worst case, I decided to completely exchange all elkos and can only recommend it to everyone.

But, as I mentioned in this thread, everyone has to decide for themselves.

Best regards
Sid1968

Edited April 27, 2020 by Sid1968

[humeur]

Sorry this texte is in French

 

Une réparation due à une défaillance des condensateurs électrolytiques est devenue un phénomène banal, inhabituel dans les années 80.

 

translate:

 

Repair due to electrolytic capacitor failure became commonplace, unusual in the 1980s.

 

 

https://qastack.fr/electronics/253976/what-happened-to-electrolytic-capacitors-in-the-21st-century

 

on the old capacitor you could reform the electrolyte  https://www.carnets-tsf.fr/condensateurs-anciens/reformer-les-condensateurs.html

sorry in French.

But, as I mentioned in this thread, everyone has to decide for themselves.

 

By cons I retain your idea of changing the regulator, If on the capacitors we are not entirely in agreement I tell you very good idea?

[Sid1968]

On 4/23/2020 at 9:56 PM, Schmitzi said:

 

Very cool list, thanks.

As I am customer at Reichelt, I ordered parts for 3 x PHA2037, 2 x Mainboard and 3 x PSU

I also made 3 shopping carts, for later use.

 

I am going to try it !! If you don´t here from me anymore, please call  the firefighters

 

 

 

 

 

 

 

Hey Schmitzi, are you still alive or do i have to call the firefighters?

 

[+Schmitzi]

6 hours ago, Sid1968 said:

 

Hey Schmitzi, are you still alive or do i have to call the firefighters?

 

 

yeah, I am here

 

I got all the stuff but buried it somewhere because of lack of time 

[Omega-TI]

2 minutes ago, Schmitzi said:

 

I got all the stuff but buried it somewhere because of lack of time 

Lack of time is the working man's enemy.  Ten more years until retirement here.  I have to wonder what kind of amazing toys we'll have for this computer then.

[+acadiel]

Do ESRs matter with any of our capacitors?  In some of my old computing equipment, I really hadn't noticed it mattering, but some folks have been super vigilant about making sure.  I saw someone made a DigiKey BOM - perhaps we can make a Mouser one too and our European friends can make one from a supplier over there.

 

I have replaced caps on a lot of 80s-2000s equipment in the past not knowing about ESR - just using high quality capacitors, and everything is still running just fine.    Some of the fun things in 80s equipment are the RIFA caps from the 80s that go into flames and let the magic smoke out (these are the high voltage across AC).  Aren't you glad we don't have these?  

 

 

 

 

[+Schmitzi]

[Sid1968]

On 7/17/2020 at 2:45 PM, acadiel said:

I have replaced caps on a lot of 80s-2000s equipment in the past not knowing about ESR - just using high quality capacitors, and everything is still running just fine.

And you really made that right, Mate!

 

 

On 7/17/2020 at 2:45 PM, acadiel said:

Some of the fun things in 80s equipment are the RIFA caps from the 80s that go into flames and let the magic smoke out (these are the high voltage across AC).  Aren't you glad we don't have these? 

 

Not having them is definitely an advantage. ?

[+mizapf]

I think this was the same thing that happened to me when, during my visit at the seller of the TI Professional Computer, we powered the machine up. A few seconds later we had a room full of smoke, but the computer still worked. At least I could lower the price by € 50,-. Back home, a closer inspection proved that a capacitor in the power supply exploded.

 

Looks spectacular, in any case.