BK Precision 1735A 30V/3A DC Power Supply. I have a 1735a that has suffered some damage. The damage seems to be only in the one spot, i was thinking of using wires to work around the effected area to see if i can get it to work. Has anyone tried to do someting similar? Has anyone the PCB drawings on the PCB?
Do this for long enough you realize that everything runs on smoke. Let that smoke out, it don't work no more.
Hmm. That's one hell of a short right there.
I would venture a guess that there's probably a component failure on this board...I would personally trace back to whatever those pads had been connected to and inspect/replace as need be.
Fixing the traces looks easy enough: the gaps are pretty small and it's easy to see what went where. But first things first, gotta get eyes on the component side. Anything that looks slightly puffed out, faded/abnormal in color, warped or crumbly has to go.
Do this for long enough you realize that everything runs on smoke. Let that smoke out, it don't work no more.
Hmm. That's one hell of a short right there.
I would venture a guess that there's probably a component failure on this board...I would personally trace back to whatever those pads had been connected to and inspect/replace as need be.
Fixing the traces looks easy enough: the gaps are pretty small and it's easy to see what went where. But first things first, gotta get eyes on the component side. Anything that looks slightly puffed out, faded/abnormal in color, warped or crumbly has to go.
So i think the component are fine, i can no find any other parts that has been damaged. I looked at the Rayex ind. LE-12T and since there are two i used them as referace for each other i could not find any damage or diffreance between the two so i am thinking they are fine, is there a way to check them? Also the jamicon 3300uF63V Capacitor (i think) looks fine, i think that the most common way to see if they are damage that they will bulge out. So using a multimeter can i check these components for damage?
It's a good idea to take a through look after that kind of failure...burned traces like that are like a super-slow-blow fuse. Any component connected to that trace could have been subjected to a prolonged current surge...that is, it coulda gotten REAL hot.
That relay looks suspicious..the one in the close up there. I would definitely recommend (carefully) pulling that one and doing the following tests. I was able to scrounge up this datasheet:
So the bottom of that relay should have five pins, you should have continuity between the two outer pins of the side with three pins (this is your 12V coil). Test in ohms, we're not looking for any specific resistance here, we're just making sure that there is resistance between these two points.
The center pin is your common terminal, and when the coil is de-energized it will connect to the terminal on the top-right corner. Test that, make sure that the resistance you read is close to 0.
The next step is an HVAC tech trick for jumping out units controlled by relays...grab a powerful magnet (rare earth, neodymium), place it next to the relay. The magnetic force you're applying here simulates the magnetic field of the energized 12v coil, and should cause the common (middle) terminal to connect to the top left terminal.
So:
Outer bottom outer terminals: check for continuity.
With no magnet: check for near 0 resistance between bottom middle terminal and top right terminal, no connection between bottom middle terminal and top left terminal
With magnet: check for near 0 resistance between bottom middle terminal and top left terminal, no connection between bottom middle terminal and top right terminal.
The reason I recommend this:
That relay is rated for 10 amps, and from the looks of it the board got awfully toasty around it. I've seen relay contacts weld shut, unable to break connection, due to exposure to overcurrent conditions. (For instance...feeding a 24vdc relay coil with 24vac...oh, and the relay controls line voltage to a motor. Coooooool.)
Any idea what happened to this thing? Water, maybe? What happened to the wiring harness, and what was it connected to?
