Help Repairing Tridonic LED Driver

[hugo_g]

Hi,

I was hoping to get some guidance on repairing an LED Driver which failed.

I discovered no damage to any components with a visual check, or no bad solder joints.

With some simple continuity tests I determined that F1, which I assume is a flameproof/fuseable resistor, failed. There was no continuity, but working drivers did have continuity.

I also assumed it as a Vishay PR02 4R7 resistor (that a 2W one). Based on the resistor colour, the wire diameter and general appearance.

So I replaced the part, connected it up and poof!! The same part blew. TBH I didn't have high hopes, I expected this failed as something else downstream had failed and this was a safety feature.

Anyway I'm out of ideas. Having working drivers I compared continuity, if something had failed open or closed, and so far following the tracks and comparing values with the DMM everything looks just the same as the working one.

I wanted to see if anyone has some ideas. This is not the kind of thing I would put back in service, but I'm treating this as a learning exercise.







https://www.tridonic.com/com/en/products/led-driver-lca-15w-180-350ma-flexc-ph-c-sr-adv.asp

Some Tech Spec's: Driver LCA 15W 180-350mA flexC PH-C SR ADV

Product description
Dimmable constant current LED Driver (SELV)
Independent LED Driver with cable clamps
Dimmable via leading edge and trailing edge phase dimmers
Dimming range 5 to 100 % (depending on dimmer)
For luminaires of protection class I and protection class II
For luminaires with M and MM as per EN 60598, VDE 0710 and VDE 0711
Temperature protection as per EN 61347-2-13 C5e
Selectable output current between 180, 250 and 350 mA
Max. output power 15 W
Up to 81 % efficiency
Nominal lifetime up to 50,000 h
5 years guarantee

Housing properties
Casing: polycarbonate, white
Type of protection IP20
Interfaces
Terminal blocks: 0° screw terminals

Functions
Overload protection
Short-circuit protection
No-load protection
Overtemperature protection
Burst protection voltage 1 kV
Surge protection voltage 1 kV (L to N)
Surge protection voltage 2 kV (L/N to earth)

[james_s]

That's exactly what I'd expect to happen, fuses very rarely blow on their own. Test all of the semiconductors, one or more of them is shorted. It's probably not really worth the effort but it could be a fun educational project.