Billtodd
Titanium
- Joined
- Feb 8, 2009
Or tales from the repairman...
"Bill, can you look at our engraver..." The 'works' has an overpriced laser engraver (two actually , one on another site) it works ok but support has been crap and now they are insisting on an overpriced service contract etc.etc.
My initial guess was psu, and ,sure enough , on inspection the neg15v was dead. So, off I trot home , and order a replacement. At base, my brain catches up and I realized I should have checked for shorts, but 30w is usually enough to generate smoke and none was observed.
A day later I have new psu and pop in to the works to fit it . I remember to check for short and, bugger, the servo galvanometer , the only thing fed by this supply is the fault. It is a bastard to remove, but 'in for penny, in for a pound ' I hump it back to the bench. Service replacement for this thing is probably in the £1000 region , so worth taking a look.
On the bench, I quickly determine the X axis driver is the problem , and take a WAG that the amp chip is dead , of course none of my usual, or unusual suppliers have stock, but eBay comes to the rescue and a replacement ordered. The driver board is a compact double sided surface mount design, so is a sod to work on. The only safe way to remove the chip is the break it and pull the legs one at a time. Needless to say , this process exonerates the chip and I soon find the culprit is a large surface mount capacitor (in my defense m'lud, aluminium electrolytic caps don't usually go short).
The buzz words of 2022 was 'supply chain' so , of course, no one - anywhere, has them in stock, except a ebayer in hongkong ...
Weeks later I have the parts (I have never had a problem with HK suppliers , they always deliver - eventually). Fitting the bloody thing on the board is another nightmare, which is why I only replaced the dead one and not them all (I await a bite on the arse).
Off I trot back to the 'works' to refit the mirror head (which is as difficult to refit as it was to remove). I power up the machine and sweet FA , nothing powers up . On close inspection the standby supply is on and so suspicion rapidly falls on a 'service' board that weeks before was showing a oddly blank display . Somewhat vexed and very very annoyed, I take the service board back to the bench and reverse engineer it - this little f###er will stop the laser running when its on board battery dies and won't allow a restart unless it is reprogrammed . So, I bypased it!
This was all before Christmas and , since someone was kind enough to give me flu , it wasn't until yesterday, that I felt well enough to return to the engraver.
With the bypassed service board refitted, bingo it fired up, homed responded , to JR's (the operator) instructions , but no visible markers and no bloody lasering. !!#%%## the air was blue . Has the laser died?, Does it need a reset after the 'service' flag? - needless to say we have no information on this machine, I am working from experience only and at this point , I'm out. My throat is sore from three weeks of coughing and my arse is cold from sitting on the floor working on this piece of shit. I retire to the pavilion, injured....
At 01:00 hours this morning, after being able to ignore the elephant, my brain catches up. The laser was working, why should it fail? Could the mirror galvo be kicked off axis? I need to get eyes on the mirrors. So , as I imagined how I might contort myself into a position to see the things , CLICK.
I emailed JR...
"John,
Did you remove the lens cap?"
"Bill, can you look at our engraver..." The 'works' has an overpriced laser engraver (two actually , one on another site) it works ok but support has been crap and now they are insisting on an overpriced service contract etc.etc.
My initial guess was psu, and ,sure enough , on inspection the neg15v was dead. So, off I trot home , and order a replacement. At base, my brain catches up and I realized I should have checked for shorts, but 30w is usually enough to generate smoke and none was observed.
A day later I have new psu and pop in to the works to fit it . I remember to check for short and, bugger, the servo galvanometer , the only thing fed by this supply is the fault. It is a bastard to remove, but 'in for penny, in for a pound ' I hump it back to the bench. Service replacement for this thing is probably in the £1000 region , so worth taking a look.
On the bench, I quickly determine the X axis driver is the problem , and take a WAG that the amp chip is dead , of course none of my usual, or unusual suppliers have stock, but eBay comes to the rescue and a replacement ordered. The driver board is a compact double sided surface mount design, so is a sod to work on. The only safe way to remove the chip is the break it and pull the legs one at a time. Needless to say , this process exonerates the chip and I soon find the culprit is a large surface mount capacitor (in my defense m'lud, aluminium electrolytic caps don't usually go short).
The buzz words of 2022 was 'supply chain' so , of course, no one - anywhere, has them in stock, except a ebayer in hongkong ...
Weeks later I have the parts (I have never had a problem with HK suppliers , they always deliver - eventually). Fitting the bloody thing on the board is another nightmare, which is why I only replaced the dead one and not them all (I await a bite on the arse).
Off I trot back to the 'works' to refit the mirror head (which is as difficult to refit as it was to remove). I power up the machine and sweet FA , nothing powers up . On close inspection the standby supply is on and so suspicion rapidly falls on a 'service' board that weeks before was showing a oddly blank display . Somewhat vexed and very very annoyed, I take the service board back to the bench and reverse engineer it - this little f###er will stop the laser running when its on board battery dies and won't allow a restart unless it is reprogrammed . So, I bypased it!
This was all before Christmas and , since someone was kind enough to give me flu , it wasn't until yesterday, that I felt well enough to return to the engraver.
With the bypassed service board refitted, bingo it fired up, homed responded , to JR's (the operator) instructions , but no visible markers and no bloody lasering. !!#%%## the air was blue . Has the laser died?, Does it need a reset after the 'service' flag? - needless to say we have no information on this machine, I am working from experience only and at this point , I'm out. My throat is sore from three weeks of coughing and my arse is cold from sitting on the floor working on this piece of shit. I retire to the pavilion, injured....
At 01:00 hours this morning, after being able to ignore the elephant, my brain catches up. The laser was working, why should it fail? Could the mirror galvo be kicked off axis? I need to get eyes on the mirrors. So , as I imagined how I might contort myself into a position to see the things , CLICK.
I emailed JR...
"John,
Did you remove the lens cap?"
Last edited:
