Hello, I'm looking for some help repairing a flashlamp power supply. It is part of a 1997-made 30W average, 4.4kW peak, 0.5-20ms pulse duration dental /jewellery spot welding laser marketed in Europe by the German companies Alphalaser and Siro Lasertec and in the US by Gramm Technology:
(picture from Gramm Technology website)
I believe that it is originally made in China for/by Sintec Optronics, although some parts are also Russian (binocular microscope head). It's almost certainly also been marketed under other designations.
The lamp looks clean, only 700000 pulses, so I'd expect to see some light at least from the trigger ignition pulse - or hear a crack, or something... but nada.
The power supply (only marking is LPL10-1 on the logic board and LPL10-2 on the trigger board) runs off a single phase mains connection. It is a 20kg unit with 4 fibre optic connections for monitoring/control. The inverter/capacitor bank is working, the voltage is fairly close to the front panel setting, but there is no flash. It's a series trigger unit with a large, high current IGBT. The control CPU seems to be operational, the UV protection works at the appropriate moment and the fans come on when the CPU thinks it's triggered a pulse.
I've checked all the electrolytic caps, 2 and 3-pin semicondutors on and around the board - IGBT, diodes, rectifiers, transistors and thyristor. No sign of a fault, no evidence of obvious arcing or high current damage to tracks or components.
Unfortunately, some kind soul has taken the time to file off all the IC markings - and now I'm stumped. I don't know how to check the trigger circuit without blowing up either the test equipment or the circuit.
I'm not even sure how to properly test whether the trigger signal is getting to the logic/trigger board.
Does anyone have any ideas or experience to share? Perhaps even a known working board for sale?
NB I am fully aware of the hazards of working on this type of equipment, I have been doing it for over 30 years.
Thank you, fellow laserists!
Pictures:
Pic 1: This is the trigger board, I suspect the fault is here somewhere... The component bolted to the board by the 4 electrolytics is, I believe, the ignition thyristor (BT151-800R).
Pic 2: Trigger board mounted in the power supply unit. At rear left, the large IGBT and the main rectifiers can be seen.
In the foreground, the top of the logic board with the 4 monitor/control fibre optics.
Pic 3: (out of focus) close-up of logic board with 4 fibre optic connectors. NB all IC markings helpfully filed off.
Pic 4: View of power supply with boards mounted on top of the capacitor bank.