Leadlight GPL-110 Modifications

[Wyvern]

Re: Leadlight GPL-110 Information

if im not mistaken this is the black wire from the photodiode connected to a transistor

 

[Double_E]

Re: Leadlight GPL-110 Information

Are we sure of that? I don't know how to track down what that part is, it looks like it might be an active amplifier. I cant see where the ground from the neg end of the battery goes, it looks like it might pass through the switch then to the black wire on the other side. Does anybod know what that part is? c19 doesn't really say much.

 

[Wyvern]

Re: Leadlight GPL-110 Information

 

[Double_E]

Re: Leadlight GPL-110 Information

Yeah, see how the switch covers the trace, it's hard to see what's going on under there.

 

[CHP]

Re: Leadlight GPL-110 Information

There are also a few vias on that circuit board. The traces under the IC in the top left are blind. Its probably best to beep out the traces. I have a partial schematic, but there are a couple nodes that are uncertain. Anyone have a broken one that they are willing to part with?

 

[LaserMod]

Re: Leadlight GPL-110 Information

I'm sorry guys but I have just found my 110 board, will post pics soon. The resistor mod is wrong, it is the SMR labelled '102' on the right of the pot. Hope no-one tried it... /ubbthreads/images/graemlins/rolleyes.gif

Anyway this board is useless as the contacts where the diode sits are broken as you will see on the images. I will also remove the button and take some angle shots.

CHP if you want me to send you the board...not a problem... PM me. /ubbthreads/images/graemlins/smile.gif

 

[LaserMod]

Re: Leadlight GPL-110 Information

Here are the images:

I have compared both a 105 and a 110. The top board is an AtlasNova - you can tell with the gold contact and generally much better 'put together' circuit compared to the other. Much better quality /ubbthreads/images/graemlins/thumbsup.gif

Front:

Front again with the buttons removed:

Back:

And I removed the two larger components so the tracks can be seen:

Cheers!

I also took some diode shots - pointless... but just for a laugh. /ubbthreads/images/graemlins/smile.gif

 

[Bengal]

Re: Leadlight GPL-110 Information

Thanks for the new pics.
and removing those components.
I hope they still work when you put them back on.
the 5 pin ic seems to be a op amp or maybe darlington pair transistor?

 

[Wyvern]

Re: Leadlight GPL-110 Information

excellent work!!!

 

[bootleg2go]

Re: Leadlight GPL-110 Information

Hi LaserModifier,
Which resistor mod is wrong? I don't quite understand.
Can you explain which mod/resistor value needs to be put back to it's original value and which one we should be changing instead and to what?

Thanks
Jack

[ QUOTE ]
LaserModifier said:
I'm sorry guys but I have just found my 110 board, will post pics soon. The resistor mod is wrong, it is the SMR labelled '102' on the right of the pot. Hope no-one tried it... /ubbthreads/images/graemlins/rolleyes.gif

Anyway this board is useless as the contacts where the diode sits are broken as you will see on the images. I will also remove the button and take some angle shots.

CHP if you want me to send you the board...not a problem... PM me. /ubbthreads/images/graemlins/smile.gif

[/ QUOTE ]

 

[LaserMod]

Re: Leadlight GPL-110 Information

Bootleg, if you compare the images of the 110 board, on mine the '102' on the 'right' of the pot is shorted with solder. That is the one to short not the one marked '332' as I originally stated in the first post of this thread...sorry. /ubbthreads/images/graemlins/frown.gif

If you have done the '332' did you get any more power then?

 

[LaserMod]

Re: Leadlight GPL-110 Information

Hmmm, my 110 looks really trashed on them images compared to bootleg's brand new one. /ubbthreads/images/graemlins/smile.gif

Although I didn't use the flash as the image tends to come out a little overexposed when the components were only an inch off the lense when photographed. Macro Lenses Rule!

 

[bootleg2go]

Re: Leadlight GPL-110 Information

Hi Lasermodifier,
I did do the shorting of the 332 (3.3k) resistor, for me it didn't really help at all. So I guess I'll put the 3.3k resistor back in. So what was the effect of shorting the 102 (1k) resistor to the right of the pot? Was there a dramatic increase in power output? let me know. If so, maybe it would be best to just reduce it from a 1k to a 220 ohm or so.

Jack

 

[drpepper1024]

Re: Leadlight GPL-110 Information

Ok, dumb question, but what relation do the numbers on the resitors have to the actual resistance? Is there like a chart that tells you what numbers correspond to which resistances?

 

[bootleg2go]

Re: Leadlight GPL-110 Information

The 1st 2 digits of the printed number are the 1st digits of the actual resistance. The 3rd digit in the printed number is the number of zeros place after the 1st two digits. So a 223 is 22000 ohms. If there are 4 digits on the resistor, that just give another digit of precision and the last digit is the number of zeros on the end, so a resistor with 2332 for instance would be 23300 or 23.3k ohms.

Jack

 

[CHP]

Re: Leadlight GPL-110 Information

LaserModifier,

Nice job! Can you tell where the wiper terminal from the pot connects? Where does the one connection go from the 1k resistor that you removed? The zener diode, to the lower left of the pot, looks like it has a via from its anode. If there is a via, can you tell me where it goes?

 

[LaserMod]

Re: Leadlight GPL-110 Information

Yeah I'll have a look...

*empties parts box all over the desk*

The good news whilst holding the circuit to a bright light source...there are no hidden tracks (that I can see) in the wafer...all the tracks are surfaced.

Just going to dig out my meter...I can't immediately see where the wiper goes...

 

[LaserMod]

Re: Leadlight GPL-110 Information

Ok, I have a better solution... just cleaned the entire board of components... I don't think this board will ever work now... /ubbthreads/images/graemlins/rolleyes.gif

I didn't expect the wiper on the pot to be directly connected to the lowest resistance side...but then again it would allow for no resistance whatsoever along these poles /ubbthreads/images/graemlins/thinking.gif

Front:

Back:

This should help with the guess work of where the tracks go...the hardest bit now is matching the contacts with the ones on the opposite side. /ubbthreads/images/graemlins/smile.gif

 

[CHP]

Re: Leadlight GPL-110 Information

I have a schematic together but the circuit looks "funky". I wouldn't have designed the circuit this way. I've simulated the circuit and it seems that the maximum current to the LD, if the feedback is disconnected, is much lower than the models without the feedback circuitry. I assumed that the IC is an op amp and that the feedback is actually a mini solar cell instead of a PD. The circuit tracks the pot movement (turn clockwise to increase output power) until the circuit's maximum current drive limit is reached. Then, further clockwise adjustment of the pot does nothing.

 

[DaFiend]

Re: Leadlight GPL-110 Information

[ QUOTE ]
LaserModifier said:

This should help with the guess work of where the tracks go...the hardest bit now is matching the contacts with the ones on the opposite side. /ubbthreads/images/graemlins/smile.gif

[/ QUOTE ]

Couldn't you use something like photo shop and flip /reverse everythinging round and and have them side by side?