The Sinclair QL Forum

t0nyt wrote:Had an early delivery! The boards were a lot bigger when I printed them out on A4...

IMG_4740.jpeg

Easier to solder on the a4 scale though

t0nyt wrote: Sun May 04, 2025 9:28 am Is it best practice to trim the legs of components like resistors before or after soldering please?

Many thanks

Yes, it is.
Much better.
But it requires some practice to get the measure and also need to use a sharp tool that you master in its use.

For resistors... no need actually.
But for other components that you will need to do it, yes... try always firstly.
For example when the soldering edge is too close to some case plastics or other boards that could scratch and damage them.

That happen to me with my first QL and... holy S**T!!!

Some background for times you doubt about how to proceed:

I cut leads before for some components and contexts.
Not only me, but lot of more experienced techs than me, do the same.

There are not only conductivity reasons (that go beyond of kind of iron solder composite) but mechanical reason and finishing reasons.
If you are considering the most common plan... new PCB with good thick measure, good leads (not too hard), good... probably no need before at all.
But do it with a CPC or Amiga 500 rev5 board with straight pins (ie. a socket or IDC pins) and not a new and calibrated tool to cut off. There is a risk, low? probably, but there is.
You will be risking your board only because with others PCBs worked fine.
Not the less when we talk about very thin boards (less than 1mm), very old PCBs, suffered PCBs... try before.
Always the tool with give some mechanical pressure on the led that force the "rivet" (very common in old and thin PCBs) and ripped them off. A good tool or a tool in good conditions this force is residual.
Sharped the tool and not maladjusted, better the cut. But better doesn't mean always certainly perfect.

Flexible leads... after is more comfortable.
Hard leads... before and specially when the board is delicate, going to be too close to a plastic or another board.

Cutting after = Any level soldering Skill
Cutting before = from medium soldering skills. It requires practicing. Otherwise you could cut in excess or not all pins at same level.

Finally an example: As you can tell... risk ZERO for another PCB or a plastic part/component nearby.
You cannot get that finishing quality/safety level in anyway cutting after

Just tried a dry run of the components that overlap (EEPROM, 74LS133 & legs for QL) and using a socket for the EEPROM fouls the other components. I should have realised that I suppose (looked fine in A4 size! )

So will use SIL headers for the EEPROM

As it happens I actually ordered the wrong 28 pin sockets (too narrow) anyway! I have the SILs in my spares box

t0nyt wrote: Thu May 08, 2025 4:30 pm Just tried a dry run of the components that overlap (EEPROM, 74LS133 & legs for QL) and using a socket for the EEPROM fouls the other components. I should have realised that I suppose (looked fine in A4 size! )
So will use SIL headers for the EEPROM
As it happens I actually ordered the wrong 28 pin sockets (too narrow) anyway! I have the SILs in my spares box

If you have problems to see properly the solder area and some leads, you can use your phone placed some on holder as an electronic microscope.
It may seems stupid, but no few times was very helpful for me and my old eyes.

Popopo wrote: Thu May 08, 2025 5:13 pm

t0nyt wrote: Thu May 08, 2025 4:30 pm Just tried a dry run of the components that overlap (EEPROM, 74LS133 & legs for QL) and using a socket for the EEPROM fouls the other components. I should have realised that I suppose (looked fine in A4 size! )
So will use SIL headers for the EEPROM
As it happens I actually ordered the wrong 28 pin sockets (too narrow) anyway! I have the SILs in my spares box

If you have problems to see properly the solder area and some leads, you can use your phone placed some on holder as an electronic microscope.
It may seems stupid, but no few times was very helpful for me and my old eyes.

I don't have a phone holder (would probably just knock it over anyway!) but I will be using the phone to examine the solder joints as I go to make sure I haven't created any shorts

Many thanks

Hi,

Lookmon Youtube, there are some good soldering videos. Look for Mr Solderfix

https://www.youtube.com/channel/UCw4EJf ... pp=desktop

He gives a good description of many types of soldering.

T48 , software 12.90 released including new firmware


btw assembled mkII should look like this ;

HI,

Looks good, does it work? and does the I2C work?

techy wrote: Fri May 09, 2025 8:28 am btw assembled mkII should look like this ;

IMG_0147.JPG

Nice!

My first attempt won't look quite like that as I'll be using sockets (as it doesn't need to fit inside the QL and means I can easily extract IC's for troubleshooting) and I'm skipping the upper 16kb to keep it as simple as possible for now so no jumper for that

That all assumes I can put it all together in the first place!

techy wrote: Fri May 09, 2025 8:28 am T48 , software 12.90 released including new firmware


btw assembled mkII should look like this ;

IMG_0147.JPG

This board looks very nice job!

Look... now what I would advice considering the image... clean/remove the residual flux.
Use alcohol iso-propyl, teeth brush and kitchen roll.

Spread some alcohol on the PCB where you have flux, put the paper on it and brush it.
Some residual flux (depending on the quality) could produce problems (short story) in short or long term.

Moreover you will be happier with the new look, fresh and clean try it please.

No idea about this project size (I cannot appreciate the height by the photo), I guest it is perfectly fine and measured, but would not be a bad idea to be careful with the plate. Your pins thread could make short with the keyboard plate (it is conductive). Moreover if it is manipulated while the QL is powered (typical opening, check something and then closing the case again while it is running). Does make sense?

For extra protection could add some caps on the pins to cover them, like IDC female row and remove them when needs.

One question techy, It seems you soldered 2 IDC pins (jumper on the right) directly to the IC (a GAL I think), Are not the tracks on the PCB? or it was a special mod for convenience?
Thanks