Solder power cable directly to circuit board

[Chrb1985]

13 minutes ago, Stuart1971 said:

I am totally at a loss, as to how you managed to do all this soldering, and now only just asking which the + and - are on the board, surely that should have been a question to ask before you started….🤔🤔 or maybe it’s just me….

also, in case this was one of the things you did not understand, “well tinned’ means that you have solder on both the end of the cable you are soldering, and also on the spot on the board to solder too, as you don’t want to have to add more solder while heating the joint, this can cause other bits to overheat, or at least in my experience…so solder on both, then touch the cable to the board and heat both until they flow, then remove iron.

But I am sure other more experienced people will have better ways of explaining  this…

Hmmm. I asked before. And I checked all the pictures I could find. And as far as I know. The plugg inside the connector is + and the exposed metal on the sides of the plug is -. That's what all google searches said. But I can't say anything else than I'm a beginner. I don't have the knowledge or the skills at all in this field. But I'm also not afraid to try new things. And 1burnt circuit board is not really the end of the world for me. So I appreciate all the help I can get here. But please don't be rude..

If someone could telle me specifically Wich of the 3 points is + and who is - it would be greatly appreciated!

[Stuart1971]

5 minutes ago, Chrb1985 said:

Hmmm. I asked before. And I checked all the pictures I could find. And as far as I know. The plugg inside the connector is + and the exposed metal on the sides of the plug is -. That's what all google searches said. But I can't say anything else than I'm a beginner. I don't have the knowledge or the skills at all in this field. But I'm also not afraid to try new things. And 1burnt circuit board is not really the end of the world for me. So I appreciate all the help I can get here. But please don't be rude..

If someone could telle me specifically Wich of the 3 points is + and who is - it would be greatly appreciated!

Appologies if you thought I was rude, it wasn’t meant that way, I was just blunt…👍🏻
positive should be the centre pin of the socket and the plug will also be centre positive…

Edited October 8, 2023 by Stuart1971

[Chrb1985]

1 minute ago, Stuart1971 said:

Appologies if you thought I was rude, it wasn’t meant that way, I was just blunt…👍🏻

Okay thank you. But do you know where I can find some decent drawings or diagrams?

[Stuart1971]

Just now, Chrb1985 said:

Okay thank you. But do you know where I can find some decent drawings or diagrams?

Of what exactly…?

[Stuart1971]

The socket will be centre pin positive…so use your multimeter to see which solder point goes to the centre pin…

Edited October 8, 2023 by Stuart1971

[Stuart1971]

Turn the multimeter to the audible setting and put the two probes one on the centre pin, and then the other on the solder points until you get the buzzer sound then you have the connection / completed circuit and so the correct solder point….

Edited October 8, 2023 by Stuart1971

[Carbon Brush]

Perhaps an element of fixing the lock on the stable door after the horse has gone.
But perhaps something of use to others contemplating modifications to equipment.

First of all I agree with the idea that the DC plugs used on the popular mounts are awful and unreliable.
However, a cable tie fastened to the body to take the strain relief is very easy to arrange and fixes 99% of issues.
In addition it still allows checks on different power supplies, etc. when fault finding.

Second. As a general rule, printed circuit boards are expensive and easy to wreck. Components are often cheap.
If you do insist on removing a component like a connector, or a chip with lots of pins, think about preserving the board before you start.
For example take a modelling grinder (Dremel) to the connector so only the pins remain. Or you can nibble it using fine side cutters.
Then remove the pins from the board one by one. Heat with the soldering iron and GENTLY pull using fine pliers/tweezers when the solder melts.
For a chip, you can cut the legs using your fine side cutters and body falls off.
Then you remove the legs one by one with minimal PCB heating.

Third. Think about your choice of solder.
Nowadays boards are built using lead free solder. In an earlier century, it was a tin/lead alloy.
Try to get hold of the traditional electrical solder for your repairs.
The old solder melts at a lower temperature and often tins wires and flows more readily than the new stuff.
Especially in the hands of a less than frequent board repair person, it is more likely to give a good outcome.

Finally, after soldering, clean off the flux residue. There may not be much - it all depends on the solder you use.
However, the more active/aggresive fluxes can mean corrosion a few years (or sooner) after exposure to the air.

Hoping this is useful.

David.

 

[Chrb1985]

28 minutes ago, Carbon Brush said:

Perhaps an element of fixing the lock on the stable door after the horse has gone.
But perhaps something of use to others contemplating modifications to equipment.

First of all I agree with the idea that the DC plugs used on the popular mounts are awful and unreliable.
However, a cable tie fastened to the body to take the strain relief is very easy to arrange and fixes 99% of issues.
In addition it still allows checks on different power supplies, etc. when fault finding.

Second. As a general rule, printed circuit boards are expensive and easy to wreck. Components are often cheap.
If you do insist on removing a component like a connector, or a chip with lots of pins, think about preserving the board before you start.
For example take a modelling grinder (Dremel) to the connector so only the pins remain. Or you can nibble it using fine side cutters.
Then remove the pins from the board one by one. Heat with the soldering iron and GENTLY pull using fine pliers/tweezers when the solder melts.
For a chip, you can cut the legs using your fine side cutters and body falls off.
Then you remove the legs one by one with minimal PCB heating.

Third. Think about your choice of solder.
Nowadays boards are built using lead free solder. In an earlier century, it was a tin/lead alloy.
Try to get hold of the traditional electrical solder for your repairs.
The old solder melts at a lower temperature and often tins wires and flows more readily than the new stuff.
Especially in the hands of a less than frequent board repair person, it is more likely to give a good outcome.

Finally, after soldering, clean off the flux residue. There may not be much - it all depends on the solder you use.
However, the more active/aggresive fluxes can mean corrosion a few years (or sooner) after exposure to the air.

Hoping this is useful.

David.

 

Ofcourse this is helpfull!

I double checked again and I'm 100% positive I made the right connections. And since I'm no expert. C30 and c31.. if they are burnt.. should it be connection there then? I thought if something is burnt it would be no connection.

I'm boy quite sure on how to approach this fix right now..

[AstroKeith]

13 hours ago, Chrb1985 said:

Okay thanks for good info. I'm not too sure I understood all of it. So can you please give me a link to what actually is + - on the board? Mabye a picture also? I'm pretty sure nothing is burnt. I have inspected it in detail. But I might be wrong. So if I could just get the wire diagram, i'll try again. 👍 But with the advice you gave me

Using this photo, you can see the 'ground plane' which covers most of the reverse side of the board. This is 99% usually ground ie negative. The small area looks like positive and has a decoupling capacitor C1 and coil connected - classic input filter. Without a circuit diagram there is a lot that can be found if you understand electronics, ie which way electrolytic capacitors are mounted, as they have clear polarity marked on them.

[malc-c]

I have to agree with the comments above.  If you have no understanding of electronics or how to test a barrel jack to see which terminal is positive or negative then you shouldn't be doing this.  I was quite taken aback by the statement that if you fried the board so be it, you can always get another... Last time I looked EQ6 boards were £150 a pop... 

If you have a connector that you need to work out the polarity the normal practice is to set the multimeter to DC volts, shove one probe into the barrel of the plug and the other to the side.  If the reading is negative swap the probes around so the red one is inside the barrel to confirm.  Having identified the positive connection (which in this case is the centre pin of the barrel connector)  the other terminals will be 0v (or GND).

Soldering is a skill that some can master to the point of reballing the processors on modern graphics cards with the right tools.  IF you still want to risk damage to your board then practice the basics which include stripping, tinning and soldering wires.  The wires should also be short, so that the solder joint is no larger than the pad you are soldering to, with the insulation as close to the pad as possible to avoid contact with other wires or components.

There was mention about "ground planes" - don't assume a solid area on a PCB is a ground plane.  Some multi-layer boards (these boards are 4 layers) use them for various reasons not always as a ground plane for the power circuit.

I still feel removing the barrel jack and the header plug and soldering the wires directly gains nothing in this instance.  In fact for the reasons I've already stated, over time more damage can be done

[Chrb1985]

17 hours ago, AstroKeith said:

Using this photo, you can see the 'ground plane' which covers most of the reverse side of the board. This is 99% usually ground ie negative. The small area looks like positive and has a decoupling capacitor C1 and coil connected - classic input filter. Without a circuit diagram there is a lot that can be found if you understand electronics, ie which way electrolytic capacitors are mounted, as they have clear polarity marked on them.

Well I'm sorry to say that you are wrong. The 2 spots Wich I soldered together is ground. The one spot you marked - is actually + I have checked this out my self and checked several forum threads and had it confirmed.

Anyway I'm ordering a new board (eq6) with the USB. Eq6 screw on power plugg. The primalucelab 3A power cable  and a baader 230 to 12V 5A 60W power supply. So I guess I'll get it working now. I'm embarrassed to say that I bought the wrong primalucelab power cable.. I got the 8A version.. and the neq6 pro mount needs 2A so it's not entirely sure that I did the dammsge by soldering alone. If I have been running the mount on 8A insted of 2A I guess this can be good for the board right?

I just got one concern right now. And that is the new board. Some sites says it will fit perfect. But the connectors don't quit look the same..  have anyone done this upgrade before? Using eq6 circuit board in neqpro mount? I know some guy in this or a similar post I posted a few days back told me he had done it.

Even though I embarrassed my self alot here, I'm learning. Learning the hard way but it is what it is. Your help is much appreciated

 

[Stuart1971]

14 hours ago, Chrb1985 said:

Well I'm sorry to say that you are wrong. The 2 spots Wich I soldered together is ground. The one spot you marked - is actually + I have checked this out my self and checked several forum threads and had it confirmed.

Anyway I'm ordering a new board (eq6) with the USB. Eq6 screw on power plugg. The primalucelab 3A power cable  and a baader 230 to 12V 5A 60W power supply. So I guess I'll get it working now. I'm embarrassed to say that I bought the wrong primalucelab power cable.. I got the 8A version.. and the neq6 pro mount needs 2A so it's not entirely sure that I did the dammsge by soldering alone. If I have been running the mount on 8A insted of 2A I guess this can be good for the board right?

I just got one concern right now. And that is the new board. Some sites says it will fit perfect. But the connectors don't quit look the same..  have anyone done this upgrade before? Using eq6 circuit board in neqpro mount? I know some guy in this or a similar post I posted a few days back told me he had done it.

Even though I embarrassed my self alot here, I'm learning. Learning the hard way but it is what it is. Your help is much appreciated

 

“I'm embarrassed to say that I bought the wrong primalucelab power cable.. I got the 8A version.. and the neq6 pro mount needs 2Aso it's not entirely sure that I did the dammsge by soldering alone. If I have been running the mount on 8A instead of 2A I guess this can be good for the board right?‘

Yet another electronic mistake….🙈 if a cable is rated at 8 Amps, it does not mean it puts out 8 amps, it means that you can use any electronic device  that requires up to that amount, so you alway want higher rated cables than the devices you are powering, so if you mount needs 2 amps and your cable and power supply are rated higher, then that is perfect….the mount or any electrical device only draws the power it needs….so you HAVE NOT been running the mount on 8 amps at all, you have just been using a cable rated to carry 8 amps which is absolutely fine and good…the mount has been using the 2 amps it needed….

now if you had an item that required 8 amps and your cable was rated at 2 amps then you would have a real issue…😮😮

You really do not know enough at all to be messing with theses things, 😮😮

[Carbon Brush]

Echoing comments from @Stuart1971

Basically if you have to be told how to do basic soldering work. If you don't understand how volts & amps work.....What are you doing opening the box?

I started following this thread (and contributing) hoping to help.
This is my last post in this (extremely frustrating) thread.

[Stuart1971]

5 minutes ago, Carbon Brush said:

Echoing comments from @Stuart1971

Basically if you have to be told how to do basic soldering work. If you don't understand how volts & amps work.....What are you doing opening the box?

I started following this thread (and contributing) hoping to help.
This is my last post in this (extremely frustrating) thread.

Me too, I’m out now as well, it’s pushing my stress levels reading his posts TBH….🤯

[Andy ES]

On 08/10/2023 at 09:24, AstroKeith said:

Messing with modern electronics requires some basic tools and knowledge. 

Mutlimeter - essential
Temperature controlled iron with narrow tip - essential
Sharp side cutters - essential
Calibrated wire strippers - almost essential
Solder sucker or soldering wicking material
Heat shrink sleeving - essential

Going to add:

Anti Static Mat with wrist band connector and Earthing Lead - essential

[malc-c]

10 hours ago, Chrb1985 said:

I'm embarrassed to say that I bought the wrong primalucelab power cable.. I got the 8A version.. and the neq6 pro mount needs 2A so it's not entirely sure that I did the dammsge by soldering alone. If I have been running the mount on 8A insted of 2A I guess this can be good for the board right?

As mentioned you clearly have very little understanding about electronics and the way electricity works.   Most people might  be able to change the spark plugs on their car, but certainly lack the knowledge, skills and tools to mess about with the internals of the engine, and the electronics in a modern mount is no different.  

It doesn't matter if you have an 8A rated cable or a 30A rated cable, it would ONLY be an issue if the cable was rated at half an amp, i.e. a lot less than the 2A a mount typically draws when slewing (although the initial current surge that happens when the steppers start is more, which is why people will recommend a 5A rated supply.  The cable rating is not how much is fed to the mount, it's how much constant current it can handle flowing through it.

2 hours ago, Stuart1971 said:

You really do not know enough at all to be messing with theses things, 😮😮

I have to agree...  and like other cringe reading the OP's posts,.  It's bad enough when someone accidentally blows a board, but when they hack about blindly not knowing the basics, even after being advised not to, then I have no sympathy when it all goes tits up.

Edited October 10, 2023 by malc-c
typo

[bosun21]

I echo the above sentiments as well. I am an Electrical/Electronics engineer and I bowed out very early in the thread once I saw what was occurring. A little knowledge is a dangerous thing being proven once again.

[malc-c]

1 minute ago, bosun21 said:

I echo the above sentiments as well. I am an Electrical/Electronics engineer and I bowed out very early in the thread once I saw what was occurring. A little knowledge is a dangerous thing being proven once again.

I think it's knowing personal limits and when you get out of your depth (some people should never enter the water !) - Being trained to solder to ministry of defense standards at what was British Aerospace I'm comfortable at working down to SOIC level on PCBs.  But even if I had the tools I still wouldn't entertain re-balling a GPU , at least not after a lot of practice.

Seeing thick heavy gauge wires, poorly tinned and then dry jointed to the thin copper pads is so upsetting

[knobby]

On 07/10/2023 at 23:00, bosun21 said:

That won't help with finding the polarity.

It will if he uses it to check if the yellow or red is connected to the centre pin ! 

🙂

 

[bosun21]

24 minutes ago, knobby said:

It will if he uses it to check if the yellow or red is connected to the centre pin ! 

🙂

 

Still won’t show whether the polarity is correct.

[Stuart1971]

28 minutes ago, bosun21 said:

Still won’t show whether the polarity is correct.

It can if you have a multimeter with an audible sound, as mine does, as you can set it on that and if it’s a circuit it will buzz….

EDIT, sorry I misread your reply, you already know this, its whether he has it connected correctly while powered up you are referring to, I was just saying to find which connector on the back is connected to the centre pin… sorry, ignore me..👍🏻 

Edited October 10, 2023 by Stuart1971

[knobby]

1 hour ago, bosun21 said:

Still won’t show whether the polarity is correct.

Wow this has turned into an 'interesting' thread 🙂

At the risk of being argumentative, at the time of my 'battery  - wire  - bulb' suggestion, the OP had a stripped cable to connector and wanted to see if the red or yellow was positive.

Making the assumption that it was a Skywatcher supply, my suggestion would have worked. Try it yourself if you get bored, It emulates a multi meter continuity test.

 

What I (all of us really) didn't know was just how unqualified for the task the OP was  at the time.

I fail to see why you need to poo poo my suggestion ' twice '

Have I offended you 🙂

 

[DaveL59]

I'm just wondering when the classic phrase "Frying Tonight" will be uttered... 😉 

[bosun21]

59 minutes ago, knobby said:

Wow this has turned into an 'interesting' thread 🙂

At the risk of being argumentative, at the time of my 'battery  - wire  - bulb' suggestion, the OP had a stripped cable to connector and wanted to see if the red or yellow was positive.

Making the assumption that it was a Skywatcher supply, my suggestion would have worked. Try it yourself if you get bored, It emulates a multi meter continuity test.

 

What I (all of us really) didn't know was just how unqualified for the task the OP was  at the time.

I fail to see why you need to poo poo my suggestion ' twice '

Have I offended you 🙂

 

 

1 hour ago, knobby said:

Wow this has turned into an 'interesting' thread 🙂

At the risk of being argumentative, at the time of my 'battery  - wire  - bulb' suggestion, the OP had a stripped cable to connector and wanted to see if the red or yellow was positive.

Making the assumption that it was a Skywatcher supply, my suggestion would have worked. Try it yourself if you get bored, It emulates a multi meter continuity test.

 

What I (all of us really) didn't know was just how unqualified for the task the OP was  at the time.

I fail to see why you need to poo poo my suggestion ' twice '

Have I offended you 🙂

 

No not at all. It's just at the time the OP was trying to find out the polarity not the continuity for which he would need a multimeter.

[Dr_Ju_ju]

A very silly question, and very late in the day, (and I don't have one of your mounts), but does the original power socket have an internal switching mechanism, that ensures no power can 'flow' till everything is firmly seated  ???