checking electrolytic caps

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checking electrolytic caps

traymond
Hi 
Im needing to check all Caps on my C128 
to check these would I read the caps in OHM's readings?

Im going to desolder them one at a time just to know what ones are failing and if the
Electrolytic is leaking out or the CAP has a bulge on the top.

This C128 is blowing the fuse in the power source, and this power source has been built from scratch from Ray Carlsen in the U.S.A. I trust Ray's work so it must be something on the
C128's MB circuit.

I was also told isnt there a power regulator component that has 3 solder legs that could possibly
cause power problems, Should this regulator read 12VDC?   What legs do I probe when I read the voltages on this regulator?

Terry Raymond


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Re: checking electrolytic caps

Clockmeister


On 29/05/2017 7:50 AM, Terry Raymond wrote:
> Hi
> Im needing to check all Caps on my C128
> to check these would I read the caps in OHM's readings?
>
> Im going to desolder them one at a time just to know what ones are failing
> and if the
> Electrolytic is leaking out or the CAP has a bulge on the top.

If you are going to the trouble of desoldering them, just replace them
but do so with quality caps.

> This C128 is blowing the fuse in the power source, and this power source
> has been built from scratch from Ray Carlsen in the U.S.A. I trust Ray's
> work so it must be something on the
> C128's MB circuit.

I trust Ray's work too, but that is not to say something hasn't failed
in the supply. Does the fuse blow as soon as you power up the C128?
If there is a dead short in Ray's supply I would suggest that the supply
fuse will blow even if the C128 isn't turned on.

> I was also told isnt there a power regulator component that has 3 solder
> legs that could possibly
> cause power problems, Should this regulator read 12VDC?   What legs do I
> probe when I read the voltages on this regulator?
>
>

If it's a 78xx Voltage regulator then see here:
https://www.engineersgarage.com/electronic-components/7805-voltage-regulator-ic

Pin 1 is input voltage, 2 is ground and 3 will be the regulated output
voltage which should match the last two digits after the 78 part number.
IE 7805 = 5V, 7812 = 12V.



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Re: checking electrolytic caps

traymond
Hi Clockmeister,

This power source has a pigtail for powering the C64 works fine doesn't blow it's fuse
Just when powering up the C128.

This is helpful enough to find what regulator I need.

Terry

On May 28, 2017 6:06 PM, "Clockmeister" <[hidden email]> wrote:


On 29/05/2017 7:50 AM, Terry Raymond wrote:
Hi
Im needing to check all Caps on my C128
to check these would I read the caps in OHM's readings?

Im going to desolder them one at a time just to know what ones are failing
and if the
Electrolytic is leaking out or the CAP has a bulge on the top.

If you are going to the trouble of desoldering them, just replace them but do so with quality caps.

This C128 is blowing the fuse in the power source, and this power source
has been built from scratch from Ray Carlsen in the U.S.A. I trust Ray's
work so it must be something on the
C128's MB circuit.

I trust Ray's work too, but that is not to say something hasn't failed in the supply. Does the fuse blow as soon as you power up the C128?
If there is a dead short in Ray's supply I would suggest that the supply fuse will blow even if the C128 isn't turned on.

I was also told isnt there a power regulator component that has 3 solder
legs that could possibly
cause power problems, Should this regulator read 12VDC?   What legs do I
probe when I read the voltages on this regulator?



If it's a 78xx Voltage regulator then see here:
https://www.engineersgarage.com/electronic-components/7805-voltage-regulator-ic

Pin 1 is input voltage, 2 is ground and 3 will be the regulated output voltage which should match the last two digits after the 78 part number. IE 7805 = 5V, 7812 = 12V.



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Re: checking electrolytic caps

Gerrit Heitsch
On 05/30/2017 04:44 PM, Terry Raymond wrote:
> Hi Clockmeister,
>
> This power source has a pigtail for powering the C64 works fine doesn't
> blow it's fuse
> Just when powering up the C128.
>
> This is helpful enough to find what regulator I need.

You might want to check the bridge rectifier in the C128. If one of the
4 diodes in it has a short it will blow the fuse. It's the black square
next to the power switch.

  Gerrit





>
> Terry
>
> On May 28, 2017 6:06 PM, "Clockmeister" <[hidden email]
> <mailto:[hidden email]>> wrote:
>
>
>
>     On 29/05/2017 7:50 AM, Terry Raymond wrote:
>
>         Hi
>         Im needing to check all Caps on my C128
>         to check these would I read the caps in OHM's readings?
>
>         Im going to desolder them one at a time just to know what ones
>         are failing
>         and if the
>         Electrolytic is leaking out or the CAP has a bulge on the top.
>
>
>     If you are going to the trouble of desoldering them, just replace
>     them but do so with quality caps.
>
>         This C128 is blowing the fuse in the power source, and this
>         power source
>         has been built from scratch from Ray Carlsen in the U.S.A. I
>         trust Ray's
>         work so it must be something on the
>         C128's MB circuit.
>
>
>     I trust Ray's work too, but that is not to say something hasn't
>     failed in the supply. Does the fuse blow as soon as you power up the
>     C128?
>     If there is a dead short in Ray's supply I would suggest that the
>     supply fuse will blow even if the C128 isn't turned on.
>
>         I was also told isnt there a power regulator component that has
>         3 solder
>         legs that could possibly
>         cause power problems, Should this regulator read 12VDC?   What
>         legs do I
>         probe when I read the voltages on this regulator?
>
>
>
>     If it's a 78xx Voltage regulator then see here:
>     https://www.engineersgarage.com/electronic-components/7805-voltage-regulator-ic
>     <https://www.engineersgarage.com/electronic-components/7805-voltage-regulator-ic>
>
>     Pin 1 is input voltage, 2 is ground and 3 will be the regulated
>     output voltage which should match the last two digits after the 78
>     part number. IE 7805 = 5V, 7812 = 12V.
>
>
>
>            Message was sent through the cbm-hackers mailing list
>


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Re: checking electrolytic caps

traymond
Okay is the rectifier the same one found on a C64?

Can I find these like on Jameco or DIGI key or Unicorn electronics?

I could Rob one from one of my breadbin.☺

Will try the rectifier first to see if the fuse problem goes away.

Thanks 

On May 30, 2017 8:53 AM, "Gerrit Heitsch" <[hidden email]> wrote:
On 05/30/2017 04:44 PM, Terry Raymond wrote:
Hi Clockmeister,

This power source has a pigtail for powering the C64 works fine doesn't blow it's fuse
Just when powering up the C128.

This is helpful enough to find what regulator I need.

You might want to check the bridge rectifier in the C128. If one of the 4 diodes in it has a short it will blow the fuse. It's the black square next to the power switch.

 Gerrit






Terry

On May 28, 2017 6:06 PM, "Clockmeister" <[hidden email] <mailto:[hidden email]>> wrote:



    On 29/05/2017 7:50 AM, Terry Raymond wrote:

        Hi
        Im needing to check all Caps on my C128
        to check these would I read the caps in OHM's readings?

        Im going to desolder them one at a time just to know what ones
        are failing
        and if the
        Electrolytic is leaking out or the CAP has a bulge on the top.


    If you are going to the trouble of desoldering them, just replace
    them but do so with quality caps.

        This C128 is blowing the fuse in the power source, and this
        power source
        has been built from scratch from Ray Carlsen in the U.S.A. I
        trust Ray's
        work so it must be something on the
        C128's MB circuit.


    I trust Ray's work too, but that is not to say something hasn't
    failed in the supply. Does the fuse blow as soon as you power up the
    C128?
    If there is a dead short in Ray's supply I would suggest that the
    supply fuse will blow even if the C128 isn't turned on.

        I was also told isnt there a power regulator component that has
        3 solder
        legs that could possibly
        cause power problems, Should this regulator read 12VDC?   What
        legs do I
        probe when I read the voltages on this regulator?



    If it's a 78xx Voltage regulator then see here:
    https://www.engineersgarage.com/electronic-components/7805-voltage-regulator-ic
    <https://www.engineersgarage.com/electronic-components/7805-voltage-regulator-ic>

    Pin 1 is input voltage, 2 is ground and 3 will be the regulated
    output voltage which should match the last two digits after the 78
    part number. IE 7805 = 5V, 7812 = 12V.



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Re: checking electrolytic caps

MiaM
Den Thu, 1 Jun 2017 12:01:32 -0600 skrev Terry Raymond
<[hidden email]>:
> Okay is the rectifier the same one found on a C64?
>
> Can I find these like on Jameco or DIGI key or Unicorn electronics?

A rectifier is just a rectifier. Unless you want something that's 100%
identical to the original one you can just replace it with any that
fits in the physical space and has the same or higher current and
voltage ratings.

--
(\_/) Copy the bunny to your mails to help
(O.o) him achieve world domination.
(> <) Come join the dark side.
/_|_\ We have cookies.

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Re: checking electrolytic caps

traymond
Looking at the rectifier only has one number at the top and bottom 
there are no other numbers.

The top has the  + and the number
Bottom - and a number

I noticed the C64 C128 rectifiers the top number is the same but the bottom number is different
why?

Terry R

On Jun 1, 2017 4:11 PM, "Mia Magnusson" <[hidden email]> wrote:
Den Thu, 1 Jun 2017 12:01:32 -0600 skrev Terry Raymond
<[hidden email]>:
> Okay is the rectifier the same one found on a C64?
>
> Can I find these like on Jameco or DIGI key or Unicorn electronics?

A rectifier is just a rectifier. Unless you want something that's 100%
identical to the original one you can just replace it with any that
fits in the physical space and has the same or higher current and
voltage ratings.

--
(\_/) Copy the bunny to your mails to help
(O.o) him achieve world domination.
(> <) Come join the dark side.
/_|_\ We have cookies.

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Re: checking electrolytic caps

Mike Stein

Manufacturing date?
----- Original Message -----
Sent: Friday, June 02, 2017 4:19 PM
Subject: Re: checking electrolytic caps

Looking at the rectifier only has one number at the top and bottom 
there are no other numbers.

The top has the  + and the number
Bottom - and a number

I noticed the C64 C128 rectifiers the top number is the same but the bottom number is different
why?

Terry R

On Jun 1, 2017 4:11 PM, "Mia Magnusson" <[hidden email]> wrote:
Den Thu, 1 Jun 2017 12:01:32 -0600 skrev Terry Raymond
<[hidden email]>:
> Okay is the rectifier the same one found on a C64?
>
> Can I find these like on Jameco or DIGI key or Unicorn electronics?

A rectifier is just a rectifier. Unless you want something that's 100%
identical to the original one you can just replace it with any that
fits in the physical space and has the same or higher current and
voltage ratings.

--
(\_/) Copy the bunny to your mails to help
(O.o) him achieve world domination.
(> <) Come join the dark side.
/_|_\ We have cookies.

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Re: checking electrolytic caps

traymond
All I can find in the C-128 service manual is that the Full Wave Bridge rectifier outputs 9VAC
All I have on hand is a Rectifier out of one of my Breadbin 64's.
I asked Unicorn Electronics I just need to be sure its 9VAC am I correct?

-Terry Raymond

Virus-free. www.avast.com

On Sat, Jun 3, 2017 at 9:15 AM, Mike Stein <[hidden email]> wrote:
Manufacturing date?
----- Original Message -----
Sent: Friday, June 02, 2017 4:19 PM
Subject: Re: checking electrolytic caps

Looking at the rectifier only has one number at the top and bottom 
there are no other numbers.

The top has the  + and the number
Bottom - and a number

I noticed the C64 C128 rectifiers the top number is the same but the bottom number is different
why?

Terry R

On Jun 1, 2017 4:11 PM, "Mia Magnusson" <[hidden email]> wrote:
Den Thu, 1 Jun 2017 12:01:32 -0600 skrev Terry Raymond
<[hidden email]>:
> Okay is the rectifier the same one found on a C64?
>
> Can I find these like on Jameco or DIGI key or Unicorn electronics?

A rectifier is just a rectifier. Unless you want something that's 100%
identical to the original one you can just replace it with any that
fits in the physical space and has the same or higher current and
voltage ratings.

--
(\_/) Copy the bunny to your mails to help
(O.o) him achieve world domination.
(> <) Come join the dark side.
/_|_\ We have cookies.

       Message was sent through the cbm-hackers mailing list

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Re: checking electrolytic caps

Gerrit Heitsch
On 06/05/2017 03:53 AM, Terry Raymond wrote:
> All I can find in the C-128 service manual is that the Full Wave Bridge
> rectifier outputs 9VAC
> All I have on hand is a Rectifier out of one of my Breadbin 64's.
> I asked Unicorn Electronics I just need to be sure its 9VAC am I correct?

The input for the rectifier is 9V AC, the output will be DC, otherwise
it wouldn't be a rectifier. All rectifiers I know can take at least 40V
AC on the input, most have no problems with 200V (see datasheet), so the
voltage is not the issue.

Otherwise, yes, you can use one from a C64 in a C128, but verify the
pinout, it's usually printed on the top in some way.

  Gerrit



>
> -Terry Raymond
>
> <https://www.avast.com/en-us/lp-safe-emailing-3108-b?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=oa-3108-b>
> Virus-free. www.avast.com
> <https://www.avast.com/en-us/lp-safe-emailing-3108-b?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=oa-3108-b>
>
>
> <#m_-8247164432759569249_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>
> On Sat, Jun 3, 2017 at 9:15 AM, Mike Stein <[hidden email]
> <mailto:[hidden email]>> wrote:
>
>     __
>     Manufacturing date?
>
>         ----- Original Message -----
>         *From:* Terry Raymond <mailto:[hidden email]>
>         *To:* [hidden email] <mailto:[hidden email]>
>         *Sent:* Friday, June 02, 2017 4:19 PM
>         *Subject:* Re: checking electrolytic caps
>
>         Looking at the rectifier only has one number at the top and bottom
>         there are no other numbers.
>
>         The top has the  + and the number
>         Bottom - and a number
>
>         I noticed the C64 C128 rectifiers the top number is the same but
>         the bottom number is different
>         why?
>
>         Terry R
>
>         On Jun 1, 2017 4:11 PM, "Mia Magnusson" <[hidden email]
>         <mailto:[hidden email]>> wrote:
>
>             Den Thu, 1 Jun 2017 12:01:32 -0600 skrev Terry Raymond
>             <[hidden email] <mailto:[hidden email]>>:
>              > Okay is the rectifier the same one found on a C64?
>              >
>              > Can I find these like on Jameco or DIGI key or Unicorn
>             electronics?
>
>             A rectifier is just a rectifier. Unless you want something
>             that's 100%
>             identical to the original one you can just replace it with
>             any that
>             fits in the physical space and has the same or higher
>             current and
>             voltage ratings.
>
>             --
>             (\_/) Copy the bunny to your mails to help
>             (O.o) him achieve world domination.
>             (> <) Come join the dark side.
>             /_|_\ We have cookies.
>
>               Message was sent through the cbm-hackers mailing list
>
>


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