SPC900 LXmod yesyes style ;-)

[yesyes]

Indeed. That looks like normal non-LX exposures. Are you sure the switch on the cam is in LX mode, i.e. open?

[Davie]

Yeh and I've tried it both on and off to make sure :/

Double checked the wiring etc ...... ok checked it about a dozen times and cant see anything wrong with it but I might have to check it again now that I've not looked at it for a day or two.

[yesyes]

I would start by checking whether that LX mode switch really opens. You may have a short circuit there somewhere that keeps the webcam in non-LX mode all the time.

[Davie]

I have checked the switch and it does work but I never tried at the circuit board end :/ will try that when i get a minute

[Davie]

The switch works fine no easy fix for me.

I'll draw out a diagram of what I have without looking at any references and see if its the same!

[yesyes]

Sounds like a good strategy.

What happens if you select the normal SPC900 in SharpCap, not the LX version? Does the video look normal?

[Davie]

OK,

Here's the drawing I made up late lastnight with my brilliant MS paint abilities

I was tired when I made this up but I'm sure it's what I have.

The only other thing I can think on is if I have the Diodes in back to front but I don't think I have. Cathodes on the 2N4148s towards the resistors and the Zener cathode towards the wire that comes from Q3 (cathodes if I remember rightly are the ends with the stripes on them and on the drawing they are the tops of the triangles with the lines across them?

lastly these are the parts I used picked up from various threads about the mod.

M10K Min Res 10k

FH04E Sub-Min Toggle E

AY71N 1N5349 BRL

QB73Q BC548B

QL80B 1N4148

Again thanks in advance and sorry for the MS paint

[Reggie]

This is a very good resource for checking out what components do and what the markings mean:

Electronic Components

Regards,

Reggie.

[yesyes]

Davie, this does look alright to me as far as I can see from your drawing. I assume there really is no connection between the 2 serial pins on the top of your drawing?

Also, how did you connect the switch? I don't see any wires going to pin and base 7 on the webcam. Did you wire that switch directly on the webcam across pin and base 7 and then run one wire from base 7 to the "To Switch" connection in your drawing?

If that is all correct, then the only things left to check is the polarity of the diodes (cathode is the side with the ring on the diode and the separate line touching the corner of the triangle. So the serial port lines coming from the adapter are connected to the anodes) and the polarity of the transistors.

A while back I made my own diagram of the vero board I was using. It's about 1/3 down on this page:

yesyes DIY and astro :: Modding an SPC880/900 webcam for long exposure

There you should be able to see the correct polarity of the transistors.

If that still doesn't fix it, could you post a photo of the front and back of your board?

[Davie]

Yes sorry I did say it was late there is no connection between the pins.

As for pad and pin 7 yes the drawing is wrong ... Ive pin 7 going to the switch and pad 7 going to the board through a 10k resistor and then onto the switch on the same lug as the 5v wire.

Sorry about the quality of my pictures and soldering going away tomorrow so rushing around do the last 101 things before i go.

Thanks again

[Gina]

The soldering looks pretty good to me Looks neater than mine these days

[themos]

have you checked for shorts across all these troughs?

[yesyes]

Hmmm, looks alright as far as I can see....

What does it look like on the camera side? Have you broken off / bent pin 7 and 9 on the connector between the 2 camera boards?

[themos]

What are those shining bits?

[Gina]

I didn't see those - they definitely look suspicious. I go along the gaps on mine with a sharp point to make sure there are no solder bridges. I also photograph/magnify to take a really close look. This also can show up suspect joints which could be dry.

[Davie]

Thanks for pointing them out i never saw them.

Sitting in an airport at the minute but doesnt look like we are going anywhere so might get a look later on today!

Sent from my GT-I9100 using Tapatalk

[Reggie]

get some flux on the offending bits and just wipe a clean tipped solderingly hot iron down the gap, that should clear the short through surface tension, the solder will be attracted to one side of the short or the other.

[Davie]

I feel like I've hijacked the thread as I've just looked back over the last couple of pages

Chris yes the pins are cut and I've checked to make sure the circuit opens and closes with the switch.

The tracks on the stripboard were clear and I gave them a scrape to make sure.

I'm on a XP machine at the minute to try to see if thatmakes a difference over the usual Win7one but no change.

[Russe]

Sorry for asking a noob question:

How much of a difference does the LX mod make?

I tried long exp shoots w/o LX mod but only got stars, no M42...

Tried 30s 60s, 600s.

No difference.

Just realised I can't afford a proper cam and would like to give it a go...

[themos]

How much of a difference does the LX mod make?

A factor of 100? The ratio of 1/10 second to 10 seconds.

[Russe]

Sorry, I don't quite follow?!

1/10 what?

[Reggie]

the longest exposure you can do on a non modded SPC900 or spc880 webcam is 1/10th of a second, or 100milliseconds, compared to the exposure length of 10 seconds on a modded spc webcam, so, divide 10seconds by 100milliseconds to tell you how much more awesome a modded webcam is over a non-modded one

IT's 100x more awesome!!

[Russe]

Oh? In astro capture u could set the camera to long exposure???

[Russe]

So it didn't actually take long expos!!!

Shocked looking.

[Russe]

Oh right. So the longest expo after modding is 10s only?