Acclaim Lighting X-Power PRO modification

[indyld]

Yes, they definitely daisy chained. You could actually clip them together in a huge run, albeit with strategically placed breaks in the cabling chain to allow for the PSU limitations. 

The shift register thing makes sense, presumably similar to those 'self addressing' LED systems where you could just keep adding strips/tape/tiles and they'd sort themselves into order to control. Schnick Schnack springs to mind. 

Edited March 23, 2023 by indyld

[partyanimallighting]

OK. I'm back. Let's forget about the LED sticks for a while. In my absence I was poking around in these two defective units and I do have another functional unit to cross-reference but, once again, I would need some advice as to how best to proceed. The unit consists of two PCB's that connect together via 6 separate 12-pin connectors each of which consists of two outputs each of R, G and B + and -. On one unit, when I use a functional control PCB from the working unit, I'm getting full control across 16 (of 18) DMX channels. I'm getting no RED output on outputs J5 and J6 (this would be DMX channels 13 and 16) so there's an issue on this dimmer PCB. Because the two PCB's connect together I find it difficult to test anything with a meter so I decided to go the route of ASSUMPTION. I figured the most probable culprits were the 9910's and the LL2705 Mosfets so I swapped out both of these with those from the next channels (GREEN) but still no output on the RED and the GREEN remains functional. The circuit seems to be simple enough but I'm not sufficiently savvy (or competent, or knowledgeable enough) to solve this problem so far. The circuit seems simple enough. There's an actuator and a cap for each channel on the reverse of the PCB and the dimming circuit is the 9910, the LL2705, a diode, 3 SMD resistors and 2 SMD caps. I'm just not sure how to proceed. There's another issue on the control board for this particular unit but I want to resolve this output issue first then focus on the other issue. Any help to offer?

 

[indyld]

Am not completely clear from the text that you've eliminated the LEDs themselves but assuming you have. On some units, I test issues between control and drivers by taking away the control - many devices put all the LEDs at full with no signal from the controller (PCB controller, not DMX).

These circuits are pretty simple and nicely repeated on any board, giving plenty of reference points on other channels for measuring for major differences, even dead testing with a DMM. However, it won't show up everything.  Certainly, I'd diode test the output coils to ground (red probe on ground) to see if there are obvious differences between those working and not.

If you have swapped U4 and Q4 for known good ones, then other than the discrete components being out of whack, check what is driving the them. Presume there is a micro somewhere with multiple pins, one to each colour. Perhaps there is a dry joint, track cracked or short between pins.

Obviously being able to test with it powered is really the thing as you can see if the LED voltage is getting there at all.

[partyanimallighting]

Hi indyld, I have eliminated the LED's themselves by using a simple 18 x 1W RGB LED diode plate wired directly to one of the Phoenix connectors and I simply tested each individual output with this via DMX. The unit control PCB I'm using is fully functional (from the working unit when connected to it's own dimming PCB) so that also eliminates the multi-pin micros so I've confirmed for sure the the issue lies only with the RED output on RGB outputs numbers 5 and 6. As I mentioned, I've eliminated the 9910 and the LL2705 simply by swapping out with the working GREEN channel next to the faulty RED channel but based on my lack of knowledge, I haven't been able to pinpoint the faulty component on this simple dimming circuit so I'm a little disappointed with this but I'll touch up on the solder points and meter the outputs and see if I can find the issue in the mean time. Based on what I've learnt from you guys, I was really sure that the 9910 for that RED channel was blown and it would be an easy fix but I was wrong. Then I moved on to the LL 2705. Wrong again.....sigh.