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Sid1968

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

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Hello folks,

electrolytic capacitors have they names because of its liguid in it, the electrolyte. In German we call them Elko (Elektrolyt-Kodensator).

Elkos do have a minus pole and a plus pole. For that its is VERY important to solder them with the right side. The minus pole on an Elko is marked.

The older Elkos get the higher is the probability that the electrolyte drains and the Elko loses more and more its capacitance.

 

For me that was reason enough to change the Elkos on my 38 year old TI-99/4A EU PAL 1981 V2. Additionally i changed the voltage controller 78M12

on the PSU-Board with the modern 12V DC/DC-Voltage Controller TSR 1-24120, because its much more efficient and produces a LOT less heat than the

78M12 with its huge heatsink. The black plastic at the Cartridgeslot is now muuuuch cooler.

 

But... this is only what i did. Some people think that they do not need an Elko-Change until a device gets problems. Make your on decision. Iam not

responsible of what you do! And remember this is an EU PAL Version for 230V. US-Devices for 110V do very probably need other parts.

 

These are the parts that i needed. This may vary on your TI-99/4A.

 

TI-99/4A Maiboard:

22µF/25V axial. Quantity: 5. Articlenumber on www.reichelt.de: VIS MAL203036229
100µF/16V axial. Quantity: 3. Articlenumber on www.reichelt.de: AX 100/25
10µF/25V axial. Quantity: 1. Articlenumber on www.reichelt.de: AX 10/35

 

TI-99/4A PSU-Board:

3300µF/35V axial. Quantity: 1. Articlenumber on www.reichelt.de: COS 105 3300/35
1000µF/25V axial. Quantity: 1. Articlenumber on www.reichelt.de: COS 105 1000/25
470µF/12V radial. Quantity: 1. Articlenumber on www.reichelt.de: RUBY 16ZLJ470MT
47µF/16V axial. Quantity: 2. Articlenumber on www.reichelt.de: AX 47/16
4.7µF/35V axial. Quantity: 1 Articlenumber on www.reichelt.de: COS 105 4,7/50
12V DC/DC-Voltage Controller TSR 1-24120. Articlenumber on www.reichelt.de: TSR 1-24120

 

Modulator PHA 2037:
22µF/25V axial. Quantity: 3. Articlenumber on www.reichelt.de: VIS MAL203036229
0,47µF/63V radial. Quantity: 3. Articlenumber on www.reichelt.de: RAD 0,47/63
47µF/16V radial. Quantity: 1. Articlenumber on www.reichelt.de: RAD 47/16

 

Here we go:

 

 

 

This is how the mainboard and the psu-board looks before the changes:

 

1. IMG_20190909_114810942.jpg

 

Before i ordered the new Elkos, i desoldered the elkos on one side to better see its capacitances

2. IMG_20190909_154035731.jpg

 

Look at the huge heatsink on the 78M12 voltage-controller, left of the 3300uF Elko.

3. IMG_20190909_115707921.jpg

 

 

 

This is how it looks with the new Elkos and the TSR 1-24120:

 

4. IMG_20190911_191311334.jpg

 

 The videochip got a heat-conducting pad

5. IMG_20190911_191525613.jpg

 

See the TSR 1-24120 at the right side of the orange Elko. It needs no heatsink!

6. IMG_20190911_170929772.jpg

 

7. IMG_20190911_170947505.jpg

 

 

After that i changed the Elkos in my PHA 2037 PbPr to SCART RGB Modulator and readjusted the rotary potentiometer.

 

Before:

 

8. IMG_20190909_153653135.jpg

 

After:

9. IMG_20190912_132424292.jpg

 

 

Now look at the overall result. This is the picture quality on my LCD-TV.

10. IMG_20190912_132514458.jpg

 

 

11. IMG_20190912_135617652.jpg

 

 

 

Kind Regards from Germany

Sid1968

Edited by Sid1968
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Addendum for the US-Version:

 

PSU-Board:

The PSU-Board of the EU Version should be the same like the US-Version. There are different Revisions but apart from that they are equal.

Even though the line current is in the USA 60Hz and in the EU 50Hz its makes no difference. This PSU-Boards awaits 8V AC and 16V AC from

the transformer. The Transformers of the US-Version and the EU-Versions are different, because of the 110V in the US and the 220V (now 230V)

in the EU. But that are external devices. Your external "black block" is NO power adapter, its a transformer... in German we call it Trafo.

 

Mainboard:

The main difference from the US-Version to the EU-Version is the Videochip, some penny-ante stuff and maybe the quarz crystal.

The rest should be similar.

 

Please correct me, if iam wrong or if you have additions. Since i have no US-Version TI-99/4A here, i ask you if somebody could say

more detailed, what Elkos are needed on the US-Mainboard. The differences should be not so big.

 

 

Kind Regards

Sid1968

 

P.S: Feel free to post fotos of your elkochanged Boards. ;-)

Edited by Sid1968
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Solution for the US-Mainboard:

 

As you can see on this labled US-Mainboard all you for an elkochange are 9 pieces of 22uF/25V elecrolytic capacitors: Labled US-Mainboard

Could it be simpler?

 

Elkochanges (Recapping) is in the Commodore Community (VIC-20, C64, Amiga) a veeery common thing. So dont be "afraid" for it. 🙂

Edited by Sid1968

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Did anyone of you 6 billion fantastic users in this forum already recaped his TI-99/4A? 🙃

Edited by Sid1968

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Nope, not that it would hurt, but im not sure it's easy, num 1. And I'm not experiencing an issue the past 7 years.

Edited by GDMike
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The one I got off ebay does not exhibit any signs of bad caps.

 

Those old caps had great electrolyte in them.  Unless the system got hot, or subjected to really crap voltages that were way outside spec, those caps live practically forever.  Not like the cap plague caps of the 90s. Those things spooged in under a year. Nasty stuff.

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Look buddies, if an electrolytic capacitors (Elko) dies on the psu-board it could lead to some overvoltages that could kill one or more chips on your TI-99/4A.

So you will in that case only realize a "problem" with your Elkos if its too late.

 

On C64 the psu is external. So there you could change the external PSU to have no troubles. On the TI-99/4A the PSU is inside the TI-99/4A. You understand?

You must not be a soldering pro to solve the task... but you will make it on your own risk... or a buddie of you will do that for you.... or a shop (maybe arcadeshopper)

would recap your TI-99/4A). Your external black block is NO psu its only a transformer... a iron core with windings around.

 

It makes sense to change all Elkos in your TI-99/4A (mainboard and psu-board), because on the mainboard all parts will get its designated voltages again, too.

Since the Elkos are very old the risk of failures is possible. I recaped all my VIC-20, C64, Amiga and TI-99/4A and can strongly recommend that to you. ;-)

 

But... this is only an advice from me, that you hopefully look at as a forummate. Do whatever you believe is the best for your TI-99/4A, maybe with the help from a qualified electrician. 🙂

 

Kind Regards

Sid

Edited by Sid1968

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I did one of my consoles, because I thought I was having troubles with it. But in the end it was something else, none of the caps were bad. I don't think we've seen any TI systems with bad caps yet (as a group) - they really built these machines to last. The main issue is VRAM (very common now), followed by the video chip, and then I think it was the ROMs or GROMs?

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19 minutes ago, Tursi said:

I did one of my consoles, because I thought I was having troubles with it. But in the end it was something else, none of the caps were bad. I don't think we've seen any TI systems with bad caps yet (as a group) - they really built these machines to last. The main issue is VRAM (very common now), followed by the video chip, and then I think it was the ROMs or GROMs?

OK, as i wrote... waiting for the death of an Elko is an option that i dont suggest. 🙂

Edited by Sid1968

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I've been wanting to recap my TI for a while, and recently did the internal power supply.  Here's what I used :

 

3300µF/35V Radial. Quantity: 1. https://www.digikey.com/product-detail/en/panasonic-electronic-components/ECA-1VHG332/P5557-ND/245156
1000µF/25V Radial. Quantity: 1. https://www.digikey.com/product-detail/en/panasonic-electronic-components/ECA-1EHG102/P5544-ND/245143
470µF/25V radial. Quantity: 1. https://www.digikey.com/product-detail/en/panasonic-electronic-components/ECA-1EHG471/P5543-ND/245142
47µF/25V Radial. Quantity: 2. https://www.digikey.com/product-detail/en/panasonic-electronic-components/EEU-FM1E470/P12923-ND/762833
4.7µF/50V Radial. Quantity: 1. https://www.digikey.com/product-detail/en/nichicon/UPW1H4R7MDD1TD/493-11360-1-ND/4319999

 

Note that some caps have higher voltage ratings than the originals.

Also, all caps here are rated at 2000 hours at 105°C.

 

post-recap-600x550.jpg

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8 minutes ago, chue said:

Also, all caps here are rated at 2000 hours at 105°C.

83 days @ 24 hours a day or a little over 3 years @ 3 hours per day... is that correct?  What is the normal operating temperature of the power supply?

 

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13 hours ago, --- Ω --- said:

83 days @ 24 hours a day or a little over 3 years @ 3 hours per day... is that correct?  What is the normal operating temperature of the power supply?

 

I don't know about the operating temp, but the caps are rated for 2000 hours at 105C. 

 

For every 10C decrease in operating temperature, the lifetime roughly doubles.

https://electronics.stackexchange.com/a/31600/124611

 

Given that, we can expect the following lifetimes for a range of temps:

 

95 C / 203 F = 4,000 hrs

85 C / 185 F = 8,000 hrs

75 C / 167 F = 16,000 hrs

65 C / 149 F = 32,000 hrs

55 C / 131 F = 64,000 hrs

45 C / 113 = 128,000 hrs

35 C / 95 F = 256,000 hrs

25 C / 77 F = 512,000 hrs

 

According to google, you can touch something that is 140 F, and HAVE to pull your fingers away after 5 seconds.  If we assume this temperature for the TI, we get a little over 32,000 hours of continuous operating life.  At 3 hours a day, we get 10,667 days or 29 years.

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You can assume 35C to be closer to most of the internals of the 4A on average... the coffee warmer might get the caps on that board up to 45C (note: the caps, not the heatsink, which is hotter ;) ).

 

I can try my thermal camera when I get home. ;)

 

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27 minutes ago, chue said:

I don't know about the operating temp, but the caps are rated for 2000 hours at 105C

 

DOH.PNG.3c47f37bf69f382183b3014963c16786.PNG  Never mind... for some reason my aging brain did not process the CELSIUS.

 

18 minutes ago, Tursi said:

I can try my thermal camera when I get home. ;)

That would be interesting!

 

 

 

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1 hour ago, --- Ω --- said:

83 days @ 24 hours a day or a little over 3 years @ 3 hours per day... is that correct?  What is the normal operating temperature of the power supply?

 

The biggest problem with the Elkos is that they drain... the electolyte in it drains out by the years. So they looses their capacitance. Draining out is the nature of an electrolytic capacitor.

 

Its good that you changed the Elkos.

Why not changing the 12V DC/DC-Voltage Controller too? Your PSU-Board would get a loooot less warm! ;-)

Why not taking axial Elkos, instead of radial? The PSU-Board were designed for axial Elkos.

 

Cheers

Sid

 

Edited by Sid1968

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22 minutes ago, Sid1968 said:

Why not changing the 12V DC/DC-Voltage Controller too? Your PSU-Board would get a loooot less warm! ;-)

Why not taking axial Elkos, instead of radial?

I have this problem that whenever I order electronic parts, there is always one thing that I forget.  This time it was the DC-DC converter.  I will order one at a future date.

 

Digikey does not seem to sell the axial types - at least I could not find them on the site.

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10 minutes ago, chue said:

I have this problem that whenever I order electronic parts, there is always one thing that I forget.  This time it was the DC-DC converter.  I will order one at a future date.

 

Digikey does not seem to sell the axial types - at least I could not find them on the site.

Thats a reason.

When you buy your DC-DC-Converter, get the elkos for your mainboard too. ;-)

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10 hours ago, chue said:

Note that some caps have higher voltage ratings than the originals.

Also, all caps here are rated at 2000 hours at 105°C.

 

 

2000 hours is a very good value, which i recommend. But, 105°C is a MUST have on the PSU (Power Supply Unit)-Board. For those who uses Fahrenheid, at 100°Celsius water boils.

 

Cheers

Sid

Edited by Sid1968
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On 9/13/2019 at 1:42 PM, Sid1968 said:

These are the parts that i needed. This may vary on your TI-99/4A.

 

TI-99/4A Maiboard:

22µF/25V axial. Quantity: 5. Articlenumber on www.reichelt.de: VIS MAL203036229
100µF/16V axial. Quantity: 3. Articlenumber on www.reichelt.de: AX 100/25
10µF/25V axial. Quantity: 1. Articlenumber on www.reichelt.de: AX 10/35

 

TI-99/4A PSU-Board:

3300µF/35V axial. Quantity: 1. Articlenumber on www.reichelt.de: COS 105 3300/35
1000µF/25V axial. Quantity: 1. Articlenumber on www.reichelt.de: COS 105 1000/25
470µF/12V radial. Quantity: 1. Articlenumber on www.reichelt.de: RUBY 16ZLJ470MT
47µF/16V axial. Quantity: 2. Articlenumber on www.reichelt.de: AX 47/16
4.7µF/35V axial. Quantity: 1 Articlenumber on www.reichelt.de: COS 105 4,7/50
12V DC/DC-Voltage Controller TSR 1-24120. Articlenumber on www.reichelt.de: TSR 1-24120

 

Modulator PHA 2037:
22µF/25V axial. Quantity: 3. Articlenumber on www.reichelt.de: VIS MAL203036229
0,47µF/63V radial. Quantity: 3. Articlenumber on www.reichelt.de: RAD 0,47/63
47µF/16V radial. Quantity: 1. Articlenumber on www.reichelt.de: RAD 47/16

 

 

Kind Regards from Germany

Sid1968

 

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 :grin:

 

 

 

 

 

 

Edited by Schmitzi
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On 10/30/2019 at 5:18 PM, Sid1968 said:

Why not changing the 12V DC/DC-Voltage Controller too? Your PSU-Board would get a loooot less warm! ;-)

But then how would we keep our coffee warm?

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12 hours ago, 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 :grin:

 

 

 

 

 

 

Nice that I could motivate you to do something good for your TI-99/4A. Of course, the components mentioned above should also fit on your Board(s). As a precaution, I would have checked in your place beforehand whether the same electrolytic capacitors in the number mentioned above are actually required on your boards. For installation, I recommend replacing one electrolytic capacitor after the other. If you

remove all of the old electrolytic capacitors right away, errors could occur when installing the new ones. Its always a good idea to make photos BEFORE you start with your work. ;-)

 

 

!!!DON'T FORGET THAT THE CORRECT POLARITY MUST BE CARRIED OUT WHEN THE NEW ELKOS ARE INSERTED. THE MINUS POLE IS MARKED!!!

 

Remember that you do everything at your own risk, but this should help to survive the Elkochange. 😉

Edited by Sid1968
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Advice for the PHA2037 that i elkochanged above too: Turning the rotary potentiometer on the PHA2037-Board more to the left sets the color saturation higher.

 

Edited by Sid1968
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I have a silly question, why are you changing the capacitors, for now I cannot say that I have found some hs.

Before changing them you check them with an esr.

Change a chemical knowing the tolerances of this type of material, I do not notice using it unless it is effectively hs and leaks or in short circuit or is in a time base.

 

Jean Louis

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34 minutes ago, humeur said:

I have a silly question, why are you changing the capacitors, for now I cannot say that I have found some hs.

Before changing them you check them with an esr.

Change a chemical knowing the tolerances of this type of material, I do not notice using it unless it is effectively hs and leaks or in short circuit or is in a time base.

 

Jean Louis

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.

Edited by Sid1968

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