Nightbird did you buy your 16 AWG wires from online store? If so do you mind letting me know where to buy this?
Also what is the banana clips?
No bibihang. I bought my AWG 16 wires from a local store. The banana plugs I used was from old test lead wires. Banana plugs are the the ends of your test lead wires that you insert into the DMM slots.
Then I’m afraid I don’t have the knowledge or skill yet to solve your problem with your 7135s. 
Thanks ,very useful !
Sorry, I forgot to mention that both the earlier and 2nd board were 3.04A boards from IS, so they had 8x7135 (380mA versions).
The 2 7135s that that I added to the 2nd board were the 350mA 7135s.
I ran out of the 380mA 7135s earlier (and now ran out of the 350mA ones also).
EDIT: I started harvesting 7135s from the 1st board, and got the 2nd one up to 4 amps (from the bench supply), and only left it on for a second or so, but then later, when I tried to power the driver+emitter up, it doesn’t work anymore :(.
I’ll be starting to diagnose after this…
Something I’ve been wondering about. I’ve been reading how everyone keeps getting higher current reading from their DMMs by upgrading to shorter, thicker wire. Wouldn’t the truest reading of your drivers output be if you were using leads of the exact same gauge as those on the driver and emitter wires?
Ouchy, see this related post.
Testing using the best possible setup will give you an idea on what current your driver can deliver. If you’re not getting the expected current then it must be something else (battery, switch, wires, heat …). 
Hi,
So, I’ve visually inspected the board very carefully, both top and bottom, and I don’t see anything wrong. No solder bridges, no missing joints. Everything looked ok.
Putting the driver on the power supply, I am measure correct voltage when measuring voltage across the negative ring on the spring side and the + on the board.
When I apply power, and measure across the emitter, it’s showing like 0 - 0.02V.
The driver board appears to be dead, but I’m not sure what else to check?
Need pics to spot a problem. Otherwise can only assume toast. If the mcu is fried you can jumper from led+ to any Vdd pin and have a single mode regulated (high) board.
I realized that I should try to ohm between the Vdd pins and OUT and between Vdd and GND, etc., so see if I can find a short.
I’ll post some pics after that, but I don’t see any “blistered” chips, etc.
Hi,
I’ve been doing the above testing, and connections all appear to ohm out all right.
However, what I’m finding is that the Vdd pin of the AMC7135 chips, which are all tied together, are at 0V all the time, even when I have the board powered up from my bench supply. The Vdd pins appear to be coming from pin 6 of the MCU, so presumably that is how the MCU controls whether or not to drive current to the emitter, so it’s looking like the MCU is dead?
EDIT: Pics as requested:
Your AMC7135 chips in the bottom picture look either deep fried or grilled. 
That could be the problem.
Power to the mcu goes through the reverse polarity diode next to led+(red wire). Check voltage there as well. If that’s ok then yes, the mcu is fried. Try a bit less flux or clean it off as it can block test leads from making good contact.
Rufus,
Did you mean the component I circled in red in the pic in the earlier post (I modified the pic)?
Hi,
I think it’s flux - I’ll clean it up and post a new pic after I check the voltage Rufus suggested.
I see. I thought it became that way because of the heat from your soldering iron. :bigsmile:
Hi,
If it is the component I circled, then the end nearest the red emitter lead is showing input voltage (e.g., if the power supply is 3.65V, then I see 3.65V at the end of the diode nearest the red lead).
The other end of the diode shows 0V.
The markings on the diode has “||| S4” with the “|||” (3 lines) away from the at the end of the diode that is away from the red lead.
Is that diode bad then?
I can try to harvest the same diode from another board?
Or, can I just short across that diode, just to see if the driver starts working again, and then harvest/replace the diode?
Short the diode to test your mcu.
If it works then replace the diode for actuate low voltage detection (presuming the mcu is programed for that). As long as you don’t use batteries over ~4.2v and don’t care about low voltage detection or reverse polarity protection it will be fine bypassing the diode.
Ok, I’ll try that, but one thing I don’t understand. Is the zener diode in SERIES with the input voltage, i.e., is it like this:
Input+ > zener anode ——-> zener cathod > MCU pin 8
??
Is the zener for reverse polarity protection? If so, shouldn’t it be in PARALLEL with the input, rather than in SERIES?
EDIT: This is like going down a rat-hole :(.
I shorted across the zener, but I did that my bench supply voltage dropped to 0V.
So, I did some more checking, and it looks like MCU pin 4 (GND) is shorted to MCU pin 8 (Vcc)!!
EDIT 2: I am about ready to give up on this board. Things are really messed up.
I compared this board to another board (that kind of works, powers up, at least), and:
- I removed the diode completely from this board, and EVEN THEN, the MCU pins 4 and 8 are shorted to ground!!
- Poking around, I found that on this board, the “bottom” end of resistors R1 and R2 are both tied to MCU pin 8, whereas on the other, semi-working board, only R2 is tied to MCU pin 8.
I guess that if there was a complete circuit diagram of the board, maybe there’d be a chance to figure out where the short might be, but w/o a diagram, it’s really tough, because the vias run under some chips, etc. and I can’t figure out what’s going where :(!!
EDIT 3: Found this from an old post from relic:
I would jumper across the diode to see if it’s the problem just be sure your polarity is correct. The voltage drop across the diode should be .6V, from the output of the diode to gnd (across the mcu) should be Vb - .6V. Vdd on the mcu is connected to the 7135 closest to the red wire via the pin on the 7135 that is closest to the red wire so a bit of solder is all it takes to bypass the mcu(common problem when adding new led+ )wire. That bit of solder should convert a non functioning multi mode driver into a functional single mode driver if the processor is the problem. If its the processor and not the diode you can use the diode as the jumper and maintain reverse polarity protection for the 7135’s.