Proper Way to Pull Single-Ended Connectors?


n4buq
 

I'm in the process of cleaning up a very dirty 7514 (apparently belonged to Southern Railway at one time and was stored in a fairly dirty environment). As part of that, I want to remove the Main Interface board and that involves removing many, many of the single-ended push-on connectors (the type that attach to the small pins that typically interconnect individual boards).

I removed a couple of these with a small hooked tool but that doesn't seem to be the most effective way to remove them because uneven pressure on one side or the other doesn't let the connector pull straight up. I'd imagine a hooked tool with a slot in it to clear the pin and allow even pulling pressure but I don't exactly have such a tool.

Is there a better way to do this? Needle-nose pliers? Unfortunately, I need to remove about thirty of forty of these so am looking for a "best method".

Thanks,
Barry - N4BUQ


Jean-Paul
 

Barry I have no experience on 7514, but most 7000 mainframes use single or double row inlune black Molex or AMP flat ribbon cable to PCB connectiors, one name is "harmonica" style.

BEWARE!! over the decades the thin plastic deterioration causes breakage or crumbling of the connectors plastic!

VERY haed to fix.

If gentle rocking does not release then the pins may he frozen to the recipticles.

In fact removal may nit be needed, perhaps just a water or isopropyl alcohol wash can clean up the PCB.

A photo of the dirty board and close-up of connector will be useful

Bon courage

Jon


n4buq
 

Jon,

Yes, I'm familiar with the "harmonica" connectors. The 7704A uses them extensively as well as the plugins and that makes taking the 7704A apart quite a bit easier. The 7514 uses a half dozen of those to the Main Interface, but there are many, many individual slide-on connectors that must be removed in order to remove that board. The manual mentions those but I didn't realize there'd be so many of them!

Yes, I could clean it with IPA and can remove sub-boards and clean them; however, the plugin socket side covers are in very bad shape and I'd like to have the Main Interface board out to better see what I can do about that. If I had a complete set of covers, then that might not be necessary but if I have to try and find a substitute method for those, then having that board out where I can access it directly will be much better.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Jean-Paul" <jonpaul@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Thursday, May 5, 2022 7:35:03 AM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
Barry I have no experience on 7514, but most 7000 mainframes use single or
double row inlune black Molex or AMP flat ribbon cable to PCB connectiors, one
name is "harmonica" style.

BEWARE!! over the decades the thin plastic deterioration causes breakage or
crumbling of the connectors plastic!

VERY haed to fix.

If gentle rocking does not release then the pins may he frozen to the
recipticles.

In fact removal may nit be needed, perhaps just a water or isopropyl alcohol
wash can clean up the PCB.

A photo of the dirty board and close-up of connector will be useful

Bon courage

Jon



n4buq
 

While these aren't the ones I need to remove, these are the type to which I'm referring:

https://w140.com/tekwiki/images/f/fd/Tek_7514_7.jpg

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Thursday, May 5, 2022 8:07:06 AM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
Jon,

Yes, I'm familiar with the "harmonica" connectors. The 7704A uses them
extensively as well as the plugins and that makes taking the 7704A apart quite
a bit easier. The 7514 uses a half dozen of those to the Main Interface, but
there are many, many individual slide-on connectors that must be removed in
order to remove that board. The manual mentions those but I didn't realize
there'd be so many of them!

Yes, I could clean it with IPA and can remove sub-boards and clean them;
however, the plugin socket side covers are in very bad shape and I'd like to
have the Main Interface board out to better see what I can do about that. If I
had a complete set of covers, then that might not be necessary but if I have to
try and find a substitute method for those, then having that board out where I
can access it directly will be much better.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Jean-Paul" <jonpaul@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Thursday, May 5, 2022 7:35:03 AM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
Barry I have no experience on 7514, but most 7000 mainframes use single or
double row inlune black Molex or AMP flat ribbon cable to PCB connectiors, one
name is "harmonica" style.

BEWARE!! over the decades the thin plastic deterioration causes breakage or
crumbling of the connectors plastic!

VERY haed to fix.

If gentle rocking does not release then the pins may he frozen to the
recipticles.

In fact removal may nit be needed, perhaps just a water or isopropyl alcohol
wash can clean up the PCB.

A photo of the dirty board and close-up of connector will be useful

Bon courage

Jon



n4buq
 

Regarding those harmonica connectors, when I pulled one of them from one of the circuit boards last night (P1306 on the A22 board), it crumbled in my fingers. Interestingly, it was a blue connector. The other colors were okay. I have noticed that the blue connectors have crumbled more consistently in some of my plugins and I'm wondering what a specific color would have to do with this. Presumably they're all mixed with a dye but odd that blue is affected more than the other colors. Anyone else noticed this?

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Thursday, May 5, 2022 8:07:06 AM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
Jon,

Yes, I'm familiar with the "harmonica" connectors. The 7704A uses them
extensively as well as the plugins and that makes taking the 7704A apart quite
a bit easier. The 7514 uses a half dozen of those to the Main Interface, but
there are many, many individual slide-on connectors that must be removed in
order to remove that board. The manual mentions those but I didn't realize
there'd be so many of them!

Yes, I could clean it with IPA and can remove sub-boards and clean them;
however, the plugin socket side covers are in very bad shape and I'd like to
have the Main Interface board out to better see what I can do about that. If I
had a complete set of covers, then that might not be necessary but if I have to
try and find a substitute method for those, then having that board out where I
can access it directly will be much better.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Jean-Paul" <jonpaul@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Thursday, May 5, 2022 7:35:03 AM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
Barry I have no experience on 7514, but most 7000 mainframes use single or
double row inlune black Molex or AMP flat ribbon cable to PCB connectiors, one
name is "harmonica" style.

BEWARE!! over the decades the thin plastic deterioration causes breakage or
crumbling of the connectors plastic!

VERY haed to fix.

If gentle rocking does not release then the pins may he frozen to the
recipticles.

In fact removal may nit be needed, perhaps just a water or isopropyl alcohol
wash can clean up the PCB.

A photo of the dirty board and close-up of connector will be useful

Bon courage

Jon



 

Yes, It's always the blue ones that crumble.

D.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of n4buq
Sent: 06 May 2022 14:41
To: tekscopes <TekScopes@groups.io>
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?

Regarding those harmonica connectors, when I pulled one of them from one of the circuit boards last night (P1306 on the A22 board), it crumbled in my fingers. Interestingly, it was a blue connector. The other colors were okay. I have noticed that the blue connectors have crumbled more consistently in some of my plugins and I'm wondering what a specific color would have to do with this. Presumably they're all mixed with a dye but odd that blue is affected more than the other colors. Anyone else noticed this?

Thanks,
Barry - N4BUQ


EB4APL
 

Been there. You can replace the broken connectors with DuPont ones. They are cheap, widely used, i.e. in Arduino projects and in various pin counts. They are always black.

Ignacio

El 06/05/2022 a las 16:22, David C. Partridge escribió:
Yes, It's always the blue ones that crumble.

D.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of n4buq
Sent: 06 May 2022 14:41
To: tekscopes <TekScopes@groups.io>
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?

Regarding those harmonica connectors, when I pulled one of them from one of the circuit boards last night (P1306 on the A22 board), it crumbled in my fingers. Interestingly, it was a blue connector. The other colors were okay. I have noticed that the blue connectors have crumbled more consistently in some of my plugins and I'm wondering what a specific color would have to do with this. Presumably they're all mixed with a dye but odd that blue is affected more than the other colors. Anyone else noticed this?

Thanks,
Barry - N4BUQ





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n4buq
 

Ignacio,

Thanks for that tip. I have some of the four-pin type but will be getting some of the other pin-count versions. I didn't realize those would work.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "EB4APL" <eb4apl@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Friday, May 6, 2022 10:51:46 AM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
Been there. You can replace the broken connectors with DuPont ones. They
are cheap, widely used, i.e. in Arduino projects and in various pin
counts. They are always black.

Ignacio


El 06/05/2022 a las 16:22, David C. Partridge escribió:
Yes, It's always the blue ones that crumble.

D.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of n4buq
Sent: 06 May 2022 14:41
To: tekscopes <TekScopes@groups.io>
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?

Regarding those harmonica connectors, when I pulled one of them from one of the
circuit boards last night (P1306 on the A22 board), it crumbled in my fingers.
Interestingly, it was a blue connector. The other colors were okay. I have
noticed that the blue connectors have crumbled more consistently in some of my
plugins and I'm wondering what a specific color would have to do with this.
Presumably they're all mixed with a dye but odd that blue is affected more
than the other colors. Anyone else noticed this?

Thanks,
Barry - N4BUQ






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virus.
https://www.avast.com/antivirus




Bruce Atwood
 

I also had a blue one disintegrate to dust on my 7904. I put shrink tubing (blue) on every other pin. The wire to wire bonding in the flat cable keeps them in order but I drew a diagonal line across the group just to be sure.


n4buq
 

I'd thought about shrink tubing as well but if I can get appropriate DuPont holders, I'll probably to that route. I'm pretty sure the wires are color-coded such that brown is pin one, red is pin two, etc., so at least I should be able to get them connected in the proper order. Unfortunately, this one (and I don't think many, if any, in this scope) are flat-cable. That would have been handy.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Bruce Atwood" <CCDman1@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Friday, May 6, 2022 3:47:16 PM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
I also had a blue one disintegrate to dust on my 7904. I put shrink tubing
(blue) on every other pin. The wire to wire bonding in the flat cable keeps
them in order but I drew a diagonal line across the group just to be sure.



n4buq
 

Unfortunately, I discovered that that wires for that connector are not color-coded for a 1,2,3,4,5 order and I had to trace them to determine which wire goes where. Not too bad but I wish Tek had provided the cabling color-scheme but I guess that since those were all supposed to be in their respective plastic holders, then that wasn't really necessary.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Friday, May 6, 2022 4:13:33 PM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
I'd thought about shrink tubing as well but if I can get appropriate DuPont
holders, I'll probably to that route. I'm pretty sure the wires are
color-coded such that brown is pin one, red is pin two, etc., so at least I
should be able to get them connected in the proper order. Unfortunately, this
one (and I don't think many, if any, in this scope) are flat-cable. That would
have been handy.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Bruce Atwood" <CCDman1@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Friday, May 6, 2022 3:47:16 PM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
I also had a blue one disintegrate to dust on my 7904. I put shrink tubing
(blue) on every other pin. The wire to wire bonding in the flat cable keeps
them in order but I drew a diagonal line across the group just to be sure.



n4buq
 

Hi Ignacio,

I finally got around to repairing that crumbled blue connector with a black DuPont connector housing. I only had four-pin versions and decided to clip a single socket from one and CA-glue it to the side of a four-pin to make a five-pin. That worked great and I have it fully repaired. Now I no longer have to cringe every time I see those bare sockets hanging on their pins!

Thanks again,
Barry - N4BUQ

----- Original Message -----
From: "EB4APL" <eb4apl@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Friday, May 6, 2022 10:51:46 AM
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?
Been there. You can replace the broken connectors with DuPont ones. They
are cheap, widely used, i.e. in Arduino projects and in various pin
counts. They are always black.

Ignacio


El 06/05/2022 a las 16:22, David C. Partridge escribió:
Yes, It's always the blue ones that crumble.

D.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of n4buq
Sent: 06 May 2022 14:41
To: tekscopes <TekScopes@groups.io>
Subject: Re: [TekScopes] Proper Way to Pull Single-Ended Connectors?

Regarding those harmonica connectors, when I pulled one of them from one of the
circuit boards last night (P1306 on the A22 board), it crumbled in my fingers.
Interestingly, it was a blue connector. The other colors were okay. I have
noticed that the blue connectors have crumbled more consistently in some of my
plugins and I'm wondering what a specific color would have to do with this.
Presumably they're all mixed with a dye but odd that blue is affected more
than the other colors. Anyone else noticed this?

Thanks,
Barry - N4BUQ






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El software de antivirus Avast ha analizado este correo electrónico en busca de
virus.
https://www.avast.com/antivirus