Strong switcher rectifier issue

[Tim Androes]

Strong 1-3k suitcase switcher 6280106 with MS-style connector...this is the half-size version..the VIN and MOD lights are red...is there a way to fix these in the field besides the Reset button or does the unit need to go to some sort of repair shop. Unit is hooked up to a Strong Super 80 lamphouse running a 3K bulb...owner says he was running some reels and the bulb suddenly quit...then he found the switcher as noted...no other lamphouses were being run at the time. Being used in a residential installation. I tried another 6280106...when i tried to strike the bulb the switcher went dead but as soon as i turned off the Manual strike button on the lamphouse the switcher came back on...all appropriate lights green. Single phase 208 to the rectifier reads 240 VAC. there are three other similar setups in this booth but none of them are having the same problem.

[Mark Gulbrandsen]

I used to repair them in my shop, so yes, definately a shop job. Semiconductors are iffy but there are likely substitutes for them today. Have not touched one since Digital Conversions began.
By the way Strong derated them to 2.5kW. So pushing and running a 3kW lamp, especially from 240 VAC is really pushing it. It will be easier and likely less expensive to acquire another used one off Epay.

[Tim Androes]

"shop job"...that's what i was afraid of...boat anchor now, I guess. fortunately he has several more as spares. thanks, Mark.

[Mark Gulbrandsen]

No, not "Boat Anchor".... Parts Donor.... There are other things in there that can still be used to keep others going...

[Tony Bandiera Jr]

Strong 1-3k suitcase switcher 6280106 with MS-style connector...this is the half-size version..the VIN and MOD lights are red...is there a way to fix these in the field besides the Reset button or does the unit need to go to some sort of repair shop. Unit is hooked up to a Strong Super 80 lamphouse running a 3K bulb...owner says he was running some reels and the bulb suddenly quit...then he found the switcher as noted...no other lamphouses were being run at the time. Being used in a residential installation. I tried another 6280106...when i tried to strike the bulb the switcher went dead but as soon as i turned off the Manual strike button on the lamphouse the switcher came back on...all appropriate lights green. Single phase 208 to the rectifier reads 240 VAC. there are three other similar setups in this booth but none of them are having the same problem.

Inspect the lamphouse wiring harness very carefully for signs of toasted wire insulation. DO NOT touch or move it in any way! If the lamphouse internal wiring shorts, it will take out the switcher and display those same fault lights.

I found this out the hard way at a cinema I serviced.

[John Eickhof]

check ur ac mains to ground! red VIN indicates loss of leg on ac input, red MOD indicator points to loss of on board fuse on main board assy thus your only getting 120 volts on one leg of 240 the other line is faulty. remember, 120/208 has three equal legs but 120/240 has a 'high' leg approx 175v to ground! if you are hooked up on single phase but have the high leg in use the power supply will not be happy!

[Mark Gulbrandsen]

Of the 200 or so I repaired back then, I found the board mounted fuses open, diode, or diodes blown open as in the photo, occasionally also a switching transistor on the second board, occasionally a board mounted diode or two as well. The plan I finally came up with was to simply shotgun the semiconductors on both boards. Total parts cost is minimal because you have to buy large quantities to even get the diodes and transistors. Total semiconductor cost back about 2007 in 100 quantity of devices was < 30 dollars per unit. Never had a control board fail. It is transformer isolated to the switcher board. LOTS of screws to remove and replace!!!