HY1803D Power Supply Woes
I bought a
Mastech HY1803D Power Supply from Sparkfun a number
of years ago and it started flaking out. With no
load on it, it would read 100mA and 00.5v no matter
what voltage setting I dialed into it.
On the images below, if you click on the image you can get an enlargement.
Here’s the external view of the device.
At the prompting of FartingMonkey92 on the sparkfun forum I decided to dig into it and see if I could find anything obvious. Here’s what I found:
So far, so good. Didn’t see or smell anything burnt. As I was taking some closer shots, I ran onto this mess:
Of the 4 diodes, you can see the far left has completely lifted one leg and is almost touching the lead on the diode next to it. It’s a bit harder to see, but the diode on the right also has a leg that has lifted out of the PCB but not as radically as the left one.
To the left of the big 1K white resistor, there are 3 wires coming into the middle of the PCB. The top one, black and almost not visible in the shot above, was barely hanging on. On the PCB side, it was obvious that whoever put this together had lifted a pad and had hand-jumpered the wire to the trace on the backside.
On the PCB side, you can see some cold solder joints, including the holes in the solder balls where the diode legs have extracted themselves from the PCB. Was definitely a poor soldering job.
I thought this would be a piece of cake to fix and resoldered the diodes and touched up the jumper, but still couldn’t get it to work right. After getting the diodes tacked back down, the amp meter still showed a small amp with no load and the v-meter showed 36v instead of 00.5v. Still couldn’t adjust the voltage. Wasn’t really any farther along after fixing some obvious problems.
I could not find any other problems, though I’m confident there are more given how this thing was built (shoddy.) Wish there was a happy ending to this, but due to time limitations, I’m going to have to retire it and cannibalize it as opportunities present.
I bought a new EHQ Power PS3003U to replace the Mastech. Picked up the new EHQ PS at JB Saunders in Boulder yesterday.
On the images below, if you click on the image you can get an enlargement.
Here’s the external view of the device.
At the prompting of FartingMonkey92 on the sparkfun forum I decided to dig into it and see if I could find anything obvious. Here’s what I found:
So far, so good. Didn’t see or smell anything burnt. As I was taking some closer shots, I ran onto this mess:
Of the 4 diodes, you can see the far left has completely lifted one leg and is almost touching the lead on the diode next to it. It’s a bit harder to see, but the diode on the right also has a leg that has lifted out of the PCB but not as radically as the left one.
To the left of the big 1K white resistor, there are 3 wires coming into the middle of the PCB. The top one, black and almost not visible in the shot above, was barely hanging on. On the PCB side, it was obvious that whoever put this together had lifted a pad and had hand-jumpered the wire to the trace on the backside.
On the PCB side, you can see some cold solder joints, including the holes in the solder balls where the diode legs have extracted themselves from the PCB. Was definitely a poor soldering job.
I thought this would be a piece of cake to fix and resoldered the diodes and touched up the jumper, but still couldn’t get it to work right. After getting the diodes tacked back down, the amp meter still showed a small amp with no load and the v-meter showed 36v instead of 00.5v. Still couldn’t adjust the voltage. Wasn’t really any farther along after fixing some obvious problems.
I could not find any other problems, though I’m confident there are more given how this thing was built (shoddy.) Wish there was a happy ending to this, but due to time limitations, I’m going to have to retire it and cannibalize it as opportunities present.
I bought a new EHQ Power PS3003U to replace the Mastech. Picked up the new EHQ PS at JB Saunders in Boulder yesterday.
asdfasdf
