View Full Version : Ut-oh. Sudden complete lack of laser beam. [It's stuffed- confirmed]

Darren Null
09-18-2007, 6:42 PM
GCC Mercury 1 (12W)

Everything was running smoothly, finished 1 job (wood), put the next in (acrylic) and no laser beam.

I've got everything else; the head moves to where it's meant to go and looks like it's attempting to laser the right bit. I've got the red aiming beam. The red "laser on" light lights; both on the control panel and on the laser unit itself. (It goes off when you open the doors halfway through; then hiccups and comes back on when you close the doors like it's meant to (top and front doors)).

The manual suggests:

Check power (yup- lights on laser light up (both the green 'power' light and the red 'laser working light), all contacts screwed in solidly).

Is it overheating? 12W? Doubt it. Ambient is 30 degrees C, 5 degrees less than it's been coping with throughout August. Turned it off for an hour anyway...still no beam.

...and there the manual ends.

The mirrors and lenses are all fine and clean. There weren't any impacts to the machine between jobs. Head moves. Tracks are clean. Table goes up and down. Autofocus works. Every connection that I can see is in and tight.

...and there my technical expertise ends. AFAIK all the GCC stuff is working because the red 'working' light on the laser itself is going when it's meant to.

Any ideas please? *grovel, beg, whimper*

Joe Pelonio
09-18-2007, 6:52 PM
There are two things I can think of that are possibilities, neither will help you without technical support though.

First, a problem with the power supply not sending power to the tube

Second, the tube is dead

Try running an old file just to be sure it's not the way your artwork is set up.

Hopefully it's something else easier and cheaper to fix, but I'd get on the phone to the support people as soon as you can.

Darren Null
09-18-2007, 7:02 PM
It's not the artwork- I remade the file and then tried a different one before I took any of the case off.

The laser is getting 32.something volts DC, which is what it wants, according to the manual (Synrad manual). Also, the fuse in the back of the laser is fine.

I bought the machine as a repossession. I don't have support people.

Joe Pelonio
09-18-2007, 7:12 PM
It's not the artwork- I remade the file and then tried a different one before I took any of the case off.

The laser is getting 32.something volts DC, which is what it wants, according to the manual (Synrad manual). Also, the fuse in the back of the laser is fine.

I bought the machine as a repossession. I don't have support people.

Ouch! Hopefully someone with a GCC can help you, but it is sounding like a bad tube. I don't know whether those are available from Synrad or you would have to go through a dealer.

I'd at least contact GCC through their website:


Paul Proffitt
09-18-2007, 7:20 PM
Not that I know anything about that particular laser, but since no one else has mentioned it yet ... could it be a safety switch / interlock that isn't closed. My Epilog is very particular about having the door closed. When it isn't everything works except there is no beam. Just a thought.

Darren Null
09-18-2007, 8:06 PM
I'm pretty sure it's not the doors- there's a 'laser working' light, both on the laser unit itself and duplicated on the control panel- the light goes out when either the front or top doors are open and goes back on (after the customary hiccup) when the door is closed again.

It's sounding very much like I'm in ouch! country. I've emailed GCC for what it's worth, but frankly I'm not expecting any joy. GCC is split up into territories, you see, so any enquiry/quote/support etc. is referred to the relevant country; which in my case is Spain, god help me. Back when I was researching which machine to buy, the mercury was one of my first choices, so I emailed for a quote. GCC Spain took 7 weeks to get back to me, leaving me with not enough money for any reasonable sized (for my purposes) machine, as my family had been at the the machine budget in the meantime. Anyway, I emailed GCC Spain indicating my displeasure and (for bonus points) copied it to head office.
I think I'm stuffed.

The laser is Synrad, but it's been GCC-ified...there's the red beam and a couple of mirrors bolted onto the front, and a GCC control board added inside the box that I know about. I've emailed Synrad too- their support is first-class and there may be some me-replaceable board or something gone inside. It's not gas because it went so suddenly.

Larry Bratton
09-18-2007, 8:56 PM
Just a thought. Does this machine have an air assist tube? On my machine their is a tube close to the lense. I once, accidentially moved this tube so that it obstructed the beam going through the lense. Everything else worked, just like yours, but no beam. I don't know anything about GCC machines or whether or not you have this feature or not, but that little air tube shut me down. (Epilog tech solved it) Good luck!

AL Ursich
09-18-2007, 9:12 PM
Can you find a place where the laser energy comes out of the tube into the cabinet and place a piece of masking tape over the opening. Careful of mirrors. See if it burns. Burns = problem in cabinet, mirror or like above, air assist blocking the beam. No Burn then go back to door magnets, shutter, like your doing.

Good Luck,


Darren Null
09-18-2007, 9:25 PM
Good suggestions, but the beam isn't leaving the laser unit itself, down in the back of the machine.

Looks like a dissassemble the laser job. RF, maybe, whatever that is.

Frank Corker
09-19-2007, 4:37 AM
Darren when I had a couple of problems a few months ago with mine I was directed by the support group to 'trip' switches inside the machine. There may be something between the power pack and the laser that isn't accessible from the outside. When different panels are removed you might find one. This is obviously suggestion only.

Rodne Gold
09-19-2007, 7:09 AM
Get into the diagnostic mode , I think you push either Start/enter or Autofocus when you switch the machine on , you will be able to test the laser firing from there (still have to have the doors closed).
If it doesnt fire , its most likely dead and it's most likely the RF boards on the laser.
One thing to do is also reseat all connections to the motherboard and check the flexible cables.

Ralph Coton
09-19-2007, 9:33 AM
I have a mercury (25w) I just had a very recent problem with my laser in which the power diminished suddenly. Every thing on the laser checked out ok (mirrors,lens,alignment,voltages). I sent the laser tube to the company I bought the laser from. Long story short the laser tube was bad - manufacturer defect - bad electronics. I just installed the new laser tube and it works perfect. This is after ownership and usage of about a year. Hope this may help

Richard Rumancik
09-19-2007, 11:00 AM
If there is no beam at the laser itself then it appears that the tube has gone. Synrad would repair a GCC-modified tube but I don't know if there is a Synrad dealer in Spain.

You probably can't repair the RF boards (if they went bad) and apparently you need some special equipment to "tune" them after replacement. On the 25/30 watt there are two RF boards and ususally one fails, dropping power to 50%. In your case you lost 100% (but I don't know if the 12w has one or two boards.)

Synrad told me that the main mode of failure of the RF boards is the failure of a capacitor on the boards. When they refurb I think they put in a new-improved RF board design.

The lens attachment to the outside will unbolt easily so that can be moved to a different tube.

You say you are operating at 32V from the power supply. In the past there were problems because GCC set the power supply voltage to 32V on tubes calibrated (tuned) at 30VDC. This can cause stress on the RF boards. Before dropping in a new or refurbished tube get this point clarified. You can adjust the power supply voltage down to 30VDC if you need to.

I was unaware of any special GCC board inside the laser tube. (Unless you mean RF boards that had heavy-duty caps for GCC). GCC adds a harnness which is connected to the interlock circuit as I recall. You could move this harness yourself if you can find a working tube from somewhere.

If you are convinced that it is the RF board you could get a technician to test the caps on the board and replace if defective. Not sure if this would require re-tuning. It might not work as well if not re-tuned but you might get some more use out of it as a last-ditch effort.

Thinus Rabie
09-19-2007, 11:27 AM
Hi Darren ,

Wow man , you don't need this kind of bad luck !

I might not be able to help you , but can tell you that I am really hoping you solve the problem very soon.

Darren Null
09-19-2007, 5:39 PM
Thanks very much for the suggestions guys. I can't tell you how much it's appreciated. All to no avail, alas. It's toast. RF is the way to bet.

Just to clear up the loose ends then:

Frank- I was devoutly hoping for trip switches or something similar. There's a couple as the power goes into the machine, but nothing between the power supply and the laser...just a fuse and that's fine.

Rodne- Diagnostic mode is obtained on the GCC Mercury (aka Pinnacle M series) by pressing the Start/Stop & Pause keys simultaneously as you power on. To be honest, I'd already tested all the parameters from the front of the machine, apart from laser on, which I'd tested by (with software) burning something at lowish power and waving my hand across the front of the laser unit (I was panicking and didn't think of paper or other hand substitutes - "Got goggles on and the rest of me'll heal"). I can see the diagnostic mode being useful for technicians for quickly testing the whole machine without having a computer attached, but the only time an owner would really need diagnostic mode, I think, would be if there's something wrong with the control panel at the front.

Ralph- I bought the machine as a repossession from a company (in a different country) that specialises in repossessions of computer and comms equipment. They had to look up what a laser engraver was before putting it up for sale. My support options are somewhat limited.

Richard- Ah, thank you. Synrad have a distributorship in Spain, which is not the same thing as a repair centre, reading between the lines.

I don't know if the 12W has one or two boards either....something to check- if there's 2 then that changes things a bit. I'll know tomorrow.

30V vs 32V- the laser unit is a 10W one, according to Synrad specs. So it's either overdriven a bit; or GCC Marketing Department is lying to make the machine specs look a little less woossy. So maybe the 32V is necessary, but thanks for the info- if it comes to a new unit, I'll check what it was tuned at and adjust accordingly.

GCC board inside the tube- Reading back, I got hold of the wrong end of the stick on this one. When I was installing the laser and was stuck on 2 identical wires, GCC told me that "Laser control is the cable coming from inside of laser tube and it connects to laser control pcb". Of course, the pcb is on the OTHER end of the wire. I added 2 and 2 and got 5. DOH!

Thank you for the info about the capacitors. At the moment, that looks like my best (only) option.
Technicians later: I found this guide to good capacitor-failure indicators:

Look on the motherboard for the capacitors, which look like miniature batteries, or pop cans. They may be of varying heights and diameters, but in general are 1 inch in height and 1/4” to �” in diameter. Do any of these capacitors have visible leakage? If this has occurred, it will look similar to what a leaky battery looks like, with rusty corrosion along the body of the capacitor. You will also notice a browning of the board and capacitor, and it may look like a liquid has run down the motherboard.

Another sure-fire way to tell is if the capacitor has bulged. In general the capacitors will fail at either the top or bottom seal. If the top seal has bulged, it is pretty self-explanatory what you would see. Imagine a pop can left in the freezer. If the bottom seal has bulged, the capacitor will no longer be sitting flush with the board and will be pushed away and cocked at an angle. Finally, the weak point may be in the side, resulting in a bulge out the side of the capacitor. I have not seen this type of failure myself, but I have read that it is possible. Basically, if the capacitor does not resemble a pop can, it has probably failed and bulged.
Source. (http://www.epinions.com/content_3906576516)
...if nothing looks obviously amiss THEN it's time for a technician. I might even be able to get a capacitor on without help, after soldering my thumb to the board a couple of times.
As for tuning, well maybe it's possible just using the force and twiddling bits and seeing how the burn improves/diminishes. I've got two bags of perspex bits, so can guage burning depths fairly accurately. Mind you, I'd quite like to know exactly what I'm twiddling first. Maybe Synrad'll tell me....it's not like they're losing custom: with a 12W the first thing I'm going to do is upgrade ASAP. Anyway, there must be universities and laser techs who do this sort of thing.

Thinus- Thanks.

AL Ursich
09-19-2007, 10:54 PM
This is worth a read.... http://www.siliconchip.com.au/cms/A_30328/article.html

I was a Sony Service Center Tech around this time and made a bunch of money working overtime replacing Capacitors in truck loads of Computer Monitors at the time. Not officially linked..... But, I believe this was the source of the problem.

Capacitors would be the next logical place to look.

From the article ""All electrolytic capacitors have a finite life, measured in thousands of hours. Unlike the exceptional cases discussed in this article, there are usually no external signs that a capacitor is nearing its end of life. However, it is possible to determine whether a capacitor is serviceable or not by measuring it's ESR (Equivalent Series Resistance).""

Good Luck,





Rodne Gold
09-20-2007, 12:44 AM
Synrad will send you a white paper or tech instructions on how to repair the RF boards , you will soon see what is blown on em (we opened a tube once) and the parts are easily available and cost pennies.
However tuning the boards requires a specialises osciloscope and a offboard power controller.
I am not sure whether the 10w has a single or double rf board , if its double , fiddling to try tune em is most likely to result in failure of both boards on a regular basis.

However , I would not go this route , I would get a decent 25 W refurbished source to replace the 10w one , 10-12 w's is really not useful power , we have had a 12w loaner unit in one of our 30w machines and it was truly a nightmare to work with.
I understand it might be pricey initially , but i don't think you will be sorry at all.

Richard Rumancik
09-20-2007, 11:08 AM
I think Rodne is right - if you look for another tube you should probably look for a 25 watt. You might be able to get a used one for 2-3 thousand dollars US. However, it might also mean a different power supply. I don't know if they use the same power supply in the 12 watt and 25/30 watt LaserPros or not. The 10 watt tube needs only 7A and the 25 watt about 14A. If you have less than 14A supply (see the nameplate on power supply near the laser tube) you will need a different one. You could probably order from Meanwell if you can't get from GCC. It would be around $300 US. Mine is called a "27V" supply by Meanwell but was adjusted to 32V by GCC. I turned it down to 30V to protect the laser tube which was spec'd at 30V.

The info about capacitors that you found refers to electrolytic caps. I don't remember if they are electrolytic caps or not. (Other kinds of caps have different geometry.) Maybe try to get whatever info Synrad will supply first. They might show you a picture of the board.

If you think it is the caps then you could just replace them. But don't twiddle any adjustments by trial and error. You'd be better off to leave the original settings.

Looking back at my Synrad e-mails, they said "A sudden drop in power is 99% of the time the RF board (failing)."

If you do not tune after replacing caps, the laser will probably still run but mismatch between the tube frequency and the board frequency may continue to stress the caps. So - if you already know how to replace them - buy a few extras . . .

There should be a sticker on the tube that says what voltage it was tuned at. Of course, if someone adjusted it after the factory (and didn't mark it) then it is anyone's guess. Higher voltage = more stress on caps.

Just for your info, Syrad quoted me $700 US four years ago for just replacing the 2 RF boards and retuning (no re-gassing.)

Darren Null
09-20-2007, 11:55 AM
Rodne, I agree with you 150%. Unfortunately I'm just starting up after going into the laser biz with what I had left after another project went horribly wrong. Another laser just isn't an option, otherwise I'd already have another one on the way.
12W isn't terribly useful- 30W would halve the burn time on what I can do already AND extend the range of what's possible. Back when I started in computers, if you wanted to print a 5Mb graphic, you just left it on overnight, so I can cope with zen computing to a certain extent but upgrading is a high priority. IF I can get to that stage.

Al- Thanks for the info. Always useful to know. However, I think I'm dealing with caps that are already toasted, rather than on their way out, so hopefully the diagnosis will be simpler.

Richard- Thanks again. Some more good info to bear in mind (I'm saving this thread as we go along). You're probably right about not tuning using the force. There is another method, apparently, using a prism, a strip of wall to burn, a calculator and two boxes of headache tablets (the maths look pretty fierce), but that's made much more difficult by the beam being invisible; plus how to burn a mark in a wall without toasting the prism. Could be tricky. And -the thought occurs to me- it may well be possible to tune the laser outside the range of my protective goggles which could end badly. Leaving the settings where they are and taking the extra cap attrition is definitely the most sensible option.
How does one go about turning the power supply to 30V please? I might as well address that issue while I'm performing surgery. I have a voltage tester.

Thanks everybody for the help.

Martin Reynolds
09-20-2007, 12:28 PM
There's a Synrad 10W laser (http://cgi.ebay.com/SYNRAD-J48-1W-9075-CO2-LASER-NIB_W0QQitemZ280154246123QQihZ018QQcategoryZ4660QQ ssPageNameZWDVWQQrdZ1QQcmdZViewItem)up on ebay right now.

Joe Pelonio
09-20-2007, 12:55 PM
12W isn't terribly useful- 30W would halve the burn time on what I can do already AND extend the range of what's possible.
Keep in mind that not all lasers are capable of a more powerful tube without other modifications. For example I considered an upgrade to 60 watts when my 45 watt went out last time but was told by Epilog that 45 is the max for this machine.

Kim Vellore
09-20-2007, 1:06 PM
I tried to upgrade mine to 60W but the physical size of the 60W laser tube is bigger than the 45W to fit in the same place. The power supply was also too big to fit. The 35w and 45w were the same size. I would check the dimensions and mounting drawings of the new laser and the power supply before buying.


Darren Null
09-20-2007, 1:27 PM
Good ebay find, but unfortunately even that is out of my budget right now. The fiscal outlook is bleak, as an economist would say.

As for power upgrades, the Mercury (aka Pinnacle M) comes with a range of power options from 12-100W, so there's lots of space in the bay for the right laser. As for homebrew power upgrades for machines that aren't built for it, to quote the Synrad tech support guy:
"Many have tried, but few have succeeded".

Darren Null
09-20-2007, 5:32 PM
Bonus points to everybody who guessed a blown capacitor on the RF board. Diagnosing a problem sight unseen from a different continent, just from a text description. I salute you!
Even without technical equipment, it wasn't too hard to spot the problem. I'd had the laser working for about 2 hours; which it should be able to cope with.
So tonight, I'll pore over the schematics and try to work out what all those squiggly bits are, and tomorrow it's off to Motril to see if I can't find some replacements. I might mount the replacement capacitor in a spring-clip arrangement rather than soldering it to the board if this is more likely to happen with an untuned laser. And get me a bag of spares.

Assuming those are both RF, then there's 2 in the 10W laser, just to answer the question.

Bill Cunningham
09-20-2007, 10:31 PM
Is that a burnt resistor behind it? Makes you wonder which went first, the cap or the resistor.. If you replace them, give it something to do for at least an hour and if it's still working, your gonna be one lucky guy!! I had a heathkit ham transmitter once that I would run at 100% duty cycle on radio teletype. Every so often I would hear a bang, smell 'the' smell, and know another cap and resistor had blown. When they were replaced, I replaced them with double the wattage resistor, and a much higher voltage at the same MF for the caps. Eventually, the transmitter would work all day, key down 100% power without ever blowing anything.. This may or may not work for you. Keeping in mind, a 100 watt tube type transmitter is not as fragile as a digital RF board.. Worse comes to worse, you end up with just a converter. A converter converts electricity into smoke, and I've built many of those!!:eek:

Darren Null
09-21-2007, 12:08 AM
It was definitely the capacitor that went first, judging from the charring pattern. The bit with the screw, I'm told is a variable resistor that's had the corner singed a bit. The little black square -I'm told, also- might be a mounting piece to hold the springy thing (technical term!) on securely, or might be something else.
This is the schematic (I think!):
Assuming I'm not holding it upside down, then the bit I'm after replacing could well be the bit marked "c3 100pF 500V SILVER MICA". You won't be able to tell from my knowledgeable typing and my careless bandying-about of advanced technical jargon; but I'm really not an electronicals expert.

Frank Corker
09-21-2007, 7:37 AM
"Assuming I'm not holding it upside down, then the bit I'm after replacing could well be the bit marked "c3 100pF 500V SILVER MICA". You won't be able to tell from my knowledgeable typing and my careless bandying-about of advanced technical jargon; but I'm really not an electronicals expert"

You could have fooled me. My goodness it looks a bit of a nightmare, I wish you all the best with this one Darren :eek:

Darren Null
09-21-2007, 10:49 AM
Thanks very much.

Oh yeah, a quick note to anyone else who might be contemplating this sort of homebrew madness (and it's not recommended by ANYONE, including me, but I haven't got much in the way of options here):
All wires off the RF board have to be shielded; otherwise they act as antennaes and may pick up enough power to make the unit lase unexpectedly. Just so you know.

We got hit by lightning today too. More annoying than serious- just blew a load of tiles off the wall of the balcony. I must have been Hitler in a past life, or something.

Kim Vellore
09-21-2007, 2:11 PM
You might want to replace it with a 1000pF 500V (or 1nF) capacitor not
100pF. This looks like the DC blocking capacitor and variation in its tolerance should not affect your tunning as long as you do not touch or turn C5.

If you don't get them locally you can try online

1000pF 1000V is available here

costs $2. If it blows again you can put two 2000pf 1000V in series which will be equivalent of 1000pf 2000V and you will not blow it again.

Another piece of advice the coils you see do not even touch or move them, if you do you will have to re-tune.

Good Luck

Kim Vellore
09-21-2007, 2:16 PM
Another factor to consider, if you are blowing the capacitor often which is rated as per design then there is something else wrong, may be tunning, so if the cap keeps blowing you will blow something else soon.


Darren Null
09-21-2007, 2:37 PM
Thanks very much Kim. This is the first time it's happened in my month of running the machine (reasonably hard). The power supply locally is a bit lumpy, so it could be attributable to that.

EDIT: Synrad addressed the exploding cap issue some time ago, apparently, and the current one in use is one of these:
(Cap,Porcelain,1000pF,1000v,10%,100C,Rad - ATC cap)
The mica ones had problems.

Richard Rumancik
09-21-2007, 10:09 PM
Darren - the power supply will usually have an adjustment pot that you can turn through a small hole with a jewelers screwdriver. It might be marked "V out" or "V adjust" or similar designation. You will need to put the meter on the ends of the two leads going to the laser - if I recall they go to a distribution PCB that has a bunch of fan connectors on it. So monitor the voltage and tweak the pot to the desired value.

Normally the voltage should match the one marked on the laser tube. This assumes that no one (such as GCC) has re-tuned along the way. Tuning is valid only for one input voltage. I would drop the voltage down to 30VDC if the laser is marked as such and see what it does.

If you can't cut what you used to, you might have to take some risk and adjust it back up a bit. (It might stress the caps a little, but part of the reason Synrad went to heavy duty caps is that some unnamed OEMs were not matching the tube and power supply voltage very well. To be fair, Synrad sped'd the voltage requirements poorly for a time so maybe some users were confused. With the new caps you will have more margin against mismatch.)

When I replaced my failed tube, the new tube was marked 30VDC and the laser supply was set at 32V. Synrad strongly recommended I drop the voltage to 30V. I felt that I was taking a performance hit, as the new tube did not perform as well as the old one, but since the laser tube was new it is not possible to be sure. There is a tolerance on the laser output at manufacture. A new "30 watt" could be 30 watts or 35 watts. My new tube barely made 30 watts and in the lower right I was below 30. There are losses going from the tube through 3 mirrors to the workpiece.

I would hesitate with the spring clip idea. I would rather see solder. I hope you don't need to replace caps on a regular basis. However, if you want to make it easier, I would install two very short posts of heavy wire. Then the cap could be soldered to these exposed posts. That way you don't have to pull out the boards. But make them as short as practicable and not extending upwards.

Hope you find the parts you need and get it running again. If adjacent parts have been affected by the burning you might need to get a tech to do a bit of troubleshooting to see if anything else is damaged.

Rodne Gold
09-21-2007, 11:31 PM
All we did was e-mail synrad with a pic of the blown components and the RF board and the next day had a parts list and comprehensive instruction on how to fix and tune.

Darren Null
09-22-2007, 6:05 AM
Thanks Richard. My laser actually says 'tested at 32V' so I might leave that bit alone, but it's useful to know.

All we did was e-mail synrad with a pic of the blown components and the RF board and the next day had a parts list and comprehensive instruction on how to fix and tune.
Ah it's alright for you smug city types with yer flashy ways and yer customified oscilloscopes.
I sent Synrad a picture of the exploded capacitor and details of my budget (ie, nothing) and they told me which capacitor I needed for best results and wished me luck. They're damn good at Synrad. GCC still haven't responded to my panicked email.

Darren Null
09-22-2007, 10:17 AM
Just a quick question to anybody who's passing who might know- does it matter which way round a capacitor goes in, or are they bi-directional? The ones I've got have a dot on one end which would seem to indicate that it's important which way round they go, but there's no +- or anything useful like that. Thanks.

Pete Thomas
09-22-2007, 10:27 AM
Hi Darren,
the cap in your picture is not a silver mica type, it is a ceramic capacitor. Based on the info you supplied and not seeing the actual failed part, I believe the blown cap in your picture is C6 (150pf) from what I can see in the picture and the schmetic. Excellent that you were able to get the schematic, thing with the screw is a variable cap. The end of the blown cap looks like it might be going to the ground, but your picture seems to cut off too much to confirm. You could also just ohm the one lead of the blown cap to confirm this.


Darren Null
09-22-2007, 10:47 AM
Thanks Pete. It is C3 though- Synrad have confirmed that. It looks like it's going to ground in the picture, but it's actually a contact that runs underneath the board. The schematic is the original mid-90s schematic (downloaded from Synrad's site...not bad for an old laser) back in the day when silver-mica caps seemed like a good idea. They moved over to other types as silver-mica "proved unsuitable for most applications" and now use "(Cap,Porcelain,1000pF,1000v,10%,100C,Rad - ATC cap)".

So it's a porcelain one going on now.

Do you know if it matters which way round they go?

Pete Thomas
09-22-2007, 10:49 AM
If the capacitor is electrolic yes the polarity is important, normally designated by either a + of -, I would think the red dot might be +. Also there should be an indication on the circuit board as to which is + or - if it is a required polarized cap is required.

Pete Thomas
09-22-2007, 10:51 AM
A procelin or ceramic do not have a polarity. So it should not matter which way it is installed.

Darren Null
09-22-2007, 11:09 AM
It's one of these:
Beyond that your guess is as good as mine. Better, I expect.

I asked for a (Cap,Porcelain,1000pF,1000v,10%,100C,Rad - ATC cap) and got this.

Sorry I took so long- I'm mastering a DVD at the same time and my laptop is running like a shed.

EDIT: No polarity. Excellent. Thank you very much. All I have to do now is wait for the kids to finish with the table; get a first aid kit handy (me soldering and personal injury are synonymous terms) and *GULP* go for it.

Darren Null
09-22-2007, 6:01 PM

Best birthday present I could have had! It works! Only for 2 test blips at 50% power, so I don't yet know if it'll take sustained burns & it's too late now to fire up all the kit for a test. Later today, when everyone's woken up. Despite what are possibly the ugliest soldered joints in history (I was going for speed and lack of heat rather than style). And I didn't even burn myself. Result!

Profound thanks to everyone who helped make a molehill out of a mountain. There just aren't words to express my gratitude. If I can return the favour for any of you at any point just ask & it's yours. Thank you.

An extremely honourable mention to the guys at Synrad too- they couldn't have been more helpful if I was a proper customer. Kudos to them, and I wouldn't go with another laser manufacturer on a bet now.

And GCC the ars...rectal sphincters: They haven't replied to the form I filled in on their main website. True, I didn't buy a new machine from them so they're not making money out of me right now but even so. GCC Spain and the head office are a complete waste of space and it'll be a cold day in hell before I buy a new machine from them. Other regions, your mileage may vary, but Spain...forget it.

Thank you all so much.

Darren Null
09-23-2007, 3:27 PM
YAY! 2 hours at full power and it's still working! Thanks you you guys. I'm back in the game!

Bill Cunningham
09-23-2007, 10:17 PM
OK..... NOW run right out and buy a lottery ticket.. Because you definatly have a horseshoe up your 'rectal sphincter'