On Saturday, July 29, 2017 at 3:04:09 PM UTC-4, wrote:
I apologize because have very little info on the lamp but am still
seeking guidance. My son has this lamp: Larson Electronics
epl-hb-150led. It is a 150 watt high bay type lamp. It has six LED
modules and each module is driven by its own driver board. Besides
various diodes, capacitors, inductors, and resistors each board has an
8 pin device and a power transistor. There are no other semiconductor
devices. Only one of the LED modules works properly. All the others
flash for a bit, then stay but don't come up to full brightness, and
then shut off after several seconds. Then the sequence repeats. My son
figured the LEDs were probably driven with a PWM voltage and so he
measured the frequency of the power to the LEDs. The one good LED
module is being driven at 150 Hz. The failing modules are being driven
at various lower frequencies, depending on which module he tested. My
son replaced all the electrolytic caps and this had no effect. The 8
pin device on each board has some sort of opaque coating on it that
completely obscures and numbers or letters that may be printed on it.
I think the problem with the boards is probably the power transistor.
I think the 8 pin device is either a microcontroller or a LED driver
IC that is designed to drive a power transistor. The meter my son
used to measure the frequency of the pulsed DC powering the LEDs is
undoubtably some cheap meter so I don't know how trustworthy it is.
From what my son says the lamp is supposed to be some kind of "smart"
lamp so that it is more efficient etc. and this is why I think the 8
pin device is a microcontroller or a LED driver. I think the various
frequency measurements he is seeing are the result of the power
transistors failing. I told him he should order some new ones and try
them out, especially since, according to my son, they do have legible
numbers on them. Since I'm really busy right now and don't know much
about how these things work anyway I'm asking for some advice and
opinions. So, is the 8 pin device probably a microcontroller? And are
failing power transistors probably the problem? What can my son do to
determine what the 8 pin device is?
Thanks,
Eric

Have you been able to separate in the driver modules from the LED array? The picture shows what looks like 12 "bulbs". Are each of these single large die LEDs or are they made up of many small LED dies in an array?

If you can swap the electronics from the working module to one of the misbehaving LEDs, you can see if it's an LED problem or driver board. From what I've seen over the years, it's more likely the LEDs are crapping out than the driver boards unless the boards are particularly poorly made or designed.

I don't have a lot of faith in high wattage LEDs. Have you contacted the manufacturer?