The Sinclair QL Forum

hi all,

Unfortunately i managed to break my 2nd (standard-)qimsi keyboad-connector now. The usb connector simply broke off its solder-pads and one of the solder pads even ripped off from the pcb (after resoldering the usb connector 2 times). on the other qimsi i even manged to rip off 3 of the solder pads from the pcb not sure what i'm doing wrong to manage that 2 times now. (forgive me the mess i've created in a lousy try to repair it)

I want to try repairing it, but would need some info if there are alternatives to these tiny usb-pads where i could solder some wires to my own usb-connector. I know the outer-left (orientation as on the picture) has a pad on the backside and the outer-right also. if im not wrong the 2nd from left is anyhow unused (correct?) so i would need some alternative solder-pads for the 3rd and 4th from the left-side because when i use the existing pads to solder wires on them, the just rip off quite easy again ...

anyone can help me with that ?

Hi,

soldering wires will definitely not last long. From the picture you shared it seems possible to solder an original USB connector again. Connecting the right hand via could be a challenge. But it's worth a try
This is the way I would got.

Best regards,

Stephan

Hi,

sorry to hear about your bad luck. From the picture, it seems that only pin 1 is damaged. Right?

As you could have seen in any microUSB pinout info, that is 5V.
As you could have seen in any QL ROM port doc, pin B1 is also 5V.
As you could have seen in the QIMSI doc, I/O port pin 2 is also 5V.

You can guess the solutions yourself...

- Solder the connector again, and wire 5V from ROM port pad B1 to pin 1 of the connector.
- Alternatively, solder microUSB pin 1 to the other microUSB socket's pin 1.
- Alternatively, solder microUSB pin 1 to I/O port pin 2.

(By the way, I have improved stability somewhat in QIMSI Gold, by increasing the copper area to which the retainers are soldered.)

All the best
Peter

Hi

Sorry to hear this happened, I had the same or actually worse.

I cleaned the pads from old solder and used solder paste to solder a new connector, then I took the copper strands from a thin cable and soldered, take care so you don't short something. I used epoxy to make it stable, so possible but fiddly.
First measure so you have continuity from pads to vias.

/Chris

For wiring, one can use enameled copper wire, so there is no risk of shorts.

thx for your help so far, i guess i'll go ahead (for this QIMSI) with

- Solder the connector again, and wire 5V from ROM port pad B1 to pin 1 of the connector.
- Alternatively, solder microUSB pin 1 to the other microUSB socket's pin 1.
- Alternatively, solder microUSB pin 1 to I/O port pin 2.

you'r right, i should have been able to figure that out by looking at the micro-usb pinout...

But: are there some solder-pads (other than those for the micro-usb connector) for D- / D+ i could use for a "more ruggedized" external connector ?

Hi,

Maybe Hot Glue would help with the stability of the Micro USB connectors.

I think the best idea would not use QIMSI without a case to support the connector from side ways motion that rip the connector from the PCB.

fuasn wrote: Sun Nov 24, 2024 5:30 pm But: are there some solder-pads (other than those for the micro-usb connector) for D- / D+ i could use for a "more ruggedized" external connector ?

No. However, the current PCB is somewhat more robust.
What also helps, is to use angled USB OTG cables and/or a case.

The effect of the straight OTG adaptor cable on the PCB's USB connector mountings did worry me a bit at first. I have ordered one of the 3D printed cases (not arrived yet) to see if that would help relieve the stress on it a little. As mine was from the more recent batch of QIMSI-Golds and you say it's a little more rugged now, hopefully I'm worrying too much. Been very happy with the original QIMSI and its case on my other Gold Card QL, so I hope I'll be equally happy with this one.

Hi,

The mouse connector on my QIMSI came off because the USB cable got caught on the Computer desk, the only damage was a securing Pad, the USB connector pads were undamaged.

I resoldered the connector back on and fitted the QIMSI board into a case, which gives a little more strain relief.

Maybe a new case design could be done to add more strain relief on the QIMSI Gold connectors.