MK1 sc connections

[egomon]

Hi.

I hve one MK1 with different chip in it and I dont know where the negative end of the sc is gooing to go ( the one which is not on the display side)?

If someone could help me with that, I would be on my way to solder sc on its place and see if it works properly

Thanks

[charger105]

Hi Egomon.
It attaches at the rear edge of the board. This point has to connect to the negative battery terminal. Just use a multimeter to check continuity to the negative battery terminal. You could even follow the tracks visually, if you don't have a multimeter handy.

Rgds.

[egomon]

Thanx for the reply....Its morning here and I must be sleepy - forgot to post the picture

[img][img]http://img193.imageshack.us/img193/9164/picyl.jpg[/img]

Uploaded with ImageShack.us[/img]

[charger105]

I think it's here (circled in red):

Just check it for continuity with the negative battery terminal.
Rgds,
Andrew.

[egomon]

Thank you, will give it a try

[egomon]

WelI, I attached the sc and the batteries to the watch and at the beginning it worked well and then I notest that the watch display was lit all the time, but when I took it away from the bright light it when dark. and its operetaed normally. When I put it back to the bright ligth it lit up again by it self...and the display was showing seconds counting.

What would be the reason for that???

[clockace]

egomon, is it always the secs running showing? could be a bad reed. the pcb i have for the mkI you show has the rear sc soldered to the upper[back] edge of the left side resistor. that would be at the farthest left edge of andrews red cicle. it still has the old piece of wire soldered there so i guess that would be the spot. make sure you haven't gotten any solder on the trace above that point which is the post for the rear right setting reed. peter

[J Thomas]

[clockace]

i just noticed 2 of the seg driver transistors and 1 of the digit driver transistors are the older rectangular type. part of the problem?? peter

[charger105]

Hi Egomon.
Seconds are displayed when positive voltage is connected to the pin circled in green below (normally this occurs when the seconds reed is activated). If you've been sloppy when installing the SC, you may have bridged the SC attachment point (circled in blue) to this point. Check both sides of the board.


If you've done this, then when placed under a light, positive voltage from the SC will indeed activate the seconds display.
Rgds,
Andrew.

[egomon]

Hi and thanks for the reply.

I'm away on a business trip and can not do the needed re-soldering right now. But thanks for the advice. Will doo it on saturday
Jeff, do you meen ( on your pict) do I havto solder the sc to the thin wire where is your arrow tip or to the huge punch of stuff near the tip of the arrow-sorry about the poor quality of the pic, my camera is broken for a long time and must take the pic with my phone cam.

Jeff, to tinker wtih this "gooe stuff" its such a good stress relife for me and highly addictive... But there is much more to this then just soldering job ( like I was thinking at first).
I think I have to get some books from the library to get the picture of beginners electronic...I have several modules what work when I connect them to the AAA batteries but when I try with button cells and sc then its whole different story.

To:charger105

I think there is no connections between the seconds reed switch and the sc, The problem appears ( seconds are displaying) only apear when sc is in bright light, in ambient the display is dark and working normally- it's only happens in a bright light...

I can work whit this modul on saturday so will have to wait untill that...

[charger105]

I think there is no connections between the seconds reed switch and the sc, The problem appears ( seconds are displaying) only apear when sc is in bright light, in ambient the display is dark and working normally- it's only happens in a bright light...

That's exactly what would happen if there was a connection between the SC and the seconds reed. I know this because I made a similar mistake at the other end of the display. It was a mangled board and the rivet thing at the bottom of the reed post was touching the SC attachment point. When in bright light, the date displayed. When in ambient light, normal operation.

Rgds,
Andrew.

[egomon]

Ok. Will look wery close the connections. It's so bad that I'm away from home and can not do it now awww...

[egomon]

To:clockace

i just noticed 2 of the seg driver transistors and 1 of the digit driver transistors are the older rectangular type. part of the problem?? peter

The rectangular transistors are new and I solderd them in place.

I dont think thay are the problem-I have the same transistors in other one and its working fine.

Egon

[egomon]

Hi.

I think this was a short circuit problem from my soldering flux. I was quite sloppy with my cleaning up after soldering the sc and chip in place.
Now it's recharge again - but in Finland there is no sun in this time of the year so I have to recharge it under the table lamp and its very slow. Will get result's perhaps after a few days.

For now it seems work...

Thanks for the advice.

Thanks