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Unless you know of a good electronics store (good as in not Radio Shack) in town somewhere?
There WAS a place called Sarasota Electronics. They has stores in Sarasota and Ft Myers back in the early 90's. The Ft Myers store closed up around 94/95 and I never heard of them any more. I doubt they lasted due to electronics becoming disposable. But worth a look up and see if by hope they are still around in Sarasota.
While messing around with the Montego tail light, I find the LED drivers are now a switch mode power supply using current as primary control feedback. Too much current is what kills LEDs 1st. The most current the Montego brake/tail light LED's used was just 400mA in brake light mode, 100mA in tail light mode! I verified this with the good one and built up the driver circuit for those current draws.
There WAS a place called Sarasota Electronics. They has stores in Sarasota and Ft Myers back in the early 90's. The Ft Myers store closed up around 94/95 and I never heard of them any more. I doubt they lasted due to electronics becoming disposable. But worth a look up and see if by hope they are still around in Sarasota.
While messing around with the Montego tail light, I find the LED drivers are now a switch mode power supply using current as primary control feedback. Too much current is what kills LEDs 1st. The most current the Montego brake/tail light LED's used was just 400mA in brake light mode, 100mA in tail light mode! I verified this with the good one and built up the driver circuit for those current draws.
Yeah Sarasota Electronics is still there on 12th street in Sarasota and that's where I was headed. I was there about a year and a half ago and they had a good selection of parts and friendly folks behind the counter.
Well I cracked one of the driver modules open today on my break, and found everybody's all-time favorite inside... potting compound! Argh! Seems to be the silicone type stuff since it was rubbery at room temperature.
I ain't even gonna bother repairing this piece of junk so I wasn't as gentle as I should have been (broke a couple solder joints for the output leads) but I managed to get most of the compound out and expose the PCB. Notice the transistor there, it wasn't heatsinked to the aluminum housing in any way. Not sure what it's purpose is yet but considering the housing of this thing gets fairly warm in operation, I bet that transistor ain't happy.
Other side of the board. That is NOT thermal paste, it's more like silicone caulking. I scraped away at this for a bit too before giving up for now. Might try to see how this works when I head home later.
So we have a PCB driving high-power LED's with no heatsinking of it's components at all. I wonder if something fried, huh? Lol.
Hook up a 9V battery to the LED head light and see if it lights. This is how I tested the LED's on the Samsung LED DLP Tv's. Just do not hold it on for long till you know the max current the LED takes.
If the LEDs are good, I have the driver ckt I made for my car's tail lights. Just need to find out the mA's the LEDS take. I would check the working LED headlight current draw to see what it is.
If possible, what's the 8 pin flat pack(last photo) IC's number on it?
Yeah I'll get those numbers. I wasn't done picking it apart, just didn't have time yesterday. Probably today or sometime this week, I'll try powering the LED by itself and see what I come up with.
Seems to be the silicone type stuff since it was rubbery at room temperature.
