How do these connectors work?

[dicky96]

Hi guys

I'm working on a vintage Onkyo amplifier - I've got it stripped down pretty well however I need to get this PCB off (see pics) to get to the one underneath which has a dodgy rotary selector switch.

Most likely then I may need to strip the actual switch down as after 30 years or so it has some corroded connections internally. I may get luck with switch cleaner as I a;ready did with the A-B speakers selector switch but still need to get at it first.

Problem is I have this PCB loose now but can't figure out how these black ribbon cables with white connectors disconnect and I need to do that to move the PCB out of the way

I unclipped the plastic retainers or whatever they are on a couple of the connectors but still don't see how to unplug the ribbons from the PCB and I don't want to break anything by forcing it

So what kind of PCB connectors are these and how do they unplug?

Rich

[Doc38343]

Re: How do these connectors work?

Those are old school. They actually are push in. They have a little tab that grips the side of the pin to keep them from pulling out. You have to pull firmly, carefully and strait out. They are not intended to be removed and inserted multiple times so just be careful when you do it. I have done many over the years and just recently had the same type on a UK brand power mixer... no problems if your careful. (They will go back in much easier than they come out.)

Please note there is a tool that can be used for these it looks a little like a comb and depresses the tabs so the ribbon can slide out easier. There is always a chance of damage if you just pull. I have taken the time to use a very small probe to release the really tough ones.

[dicky96]

Re: How do these connectors work?

Yes I imagine they are old-scool, the amp is a 1980s Onkyo

Some other connections in the amp are the 'wire wrap' type that as far as I know was only used in the 70s and 80s and you cant easily disconnect them as the wire just fractures if you try to unwrap it and you have to solder them back on

So basically with these the ribbon just pulls out? I have tried pulling on them (not too hard though) and they are quite stiff and don't seem to want to let go easily.

Rich

Added - no they really don't want to come loose - does the comb tool have a name?

[Doc38343]

Re: How do these connectors work?

After looking closer to enlarged photo it looks like on each end there is a release tab that allows the higher top piece to come off. OK this I do know those are very easy to break but if you are careful it can be done successfully. Remember the plastic is old. The tool had little flat prongs that slid in beside the wire. they were very hard metal and very sharp (I cut myself with one once) I could not even find one on a google search, we called it a socket release tool. I worked for a company back then so I just had stuff like that available. We use them to pull similar cables from a controller panel to a control board on chiller units. The jacks looked slightly different though. I think yours are the old two piece snap together type.
Just use care and take your time.

[Doc38343]

Re: How do these connectors work?

There is a guy on YouTube who will know for sure if you can contact him somehow.
I hope i'm not breaking any rules here but his channel is called 12voltvids.

https://www.youtube.com/channel/UCRx...NOjK5D7VB6pHyA

He has been doing a lot of vintage stuff and I'm sure he will know what you need to do.

Here is a video of a guy in a similar situation and he broke one of his so you can see clearly how they are made and work.
Hope this helps you.
https://www.youtube.com/watch?v=iIJu7YB5xHA

[dicky96]

Re: How do these connectors work?

Thanks Doc that helped a lot.

I removed the little plastic covers then used a soldering aid tool like this one https://www.alibaba.com/product-deta...1ca62dcf6EaVVU

I used the sharp round one (tool D) to gently insert into each springy metal contact and depress the contact in turn while keeping a moderate pressure pulling on the ribbon. The ribbons then came out easily.

On one or two I had to go back along the contacts again with the soldering aid tool to completely release the ribbon but it was easy to feel which ones were still gripping the ribbon cable and which ones were already free

I just hope it all goes back together so easily

Cheers
Rich

[dicky96]

Re: How do these connectors work?

Damn - I got to the switch contacts and cleaned them but now I can't get the ribbons to clip back in the PCB sockets during reassembly. They either simply fall out or are gripped on some pins and not others. Fitting the clip/top cover thingies does not help to secure the ribbon. I was careful not to break any of the top clips/covers, they are all fine. How do I fix that?

Rich

[Doc38343]

Re: How do these connectors work?

I use a very sharp but strong pointed probe (came in a soldering tools kit) and carefully pry on the edge of the springy incert to allow it to grip harder. sometimes I've had to carefully pull out on the little tab that catches on the side of the wire. I use a strong magnifier so i can see what i'm doing. Those old connectors were really not intended to be reused i don't think, but like you i have always done it the hard way.
Now days i would probably solder in a different connector but then again.. i may do exactly what you are as well...


Those are way smaller than they look but are incredibly hard stiff metal

[dicky96]

Re: How do these connectors work?

Yeah that is the type of tool I used to free the connections in the first place. Personally, I am of a mind to replace the original PCB sockets with something like molex connectors https://www.ebay.co.uk/sch/i.html?_f...ector&_sacat=0 and then fit the equivalent type connectors to the ribbon cables and sort it that way.

I honestly think that is the only reliable way. I don't have a micrometer here, I still need to bring so much more of my workshop equipment from England to this little subtropical island I now call home - would you happen to know of suitable modern connectors of the correct pin pitch to replace these?

best regards
Richard

[Doc38343]

Re: How do these connectors work?

would you happen to know of suitable modern connectors of the correct pin pitch to replace these?
best regards
Richard

Measure in mm for example 1.0 pin pitch is 1mm pin center to pin center
2.0 is 2mm center to center.. and so on an so forth.

[dicky96]

Re: How do these connectors work?

Cheers my friend - since posting I did try inserting a ribbon into a piece of vero board and found they are 0.1 inch pitch so it should be easy to replace the plugs and sockets with something modern and reliable

Rich