Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I recently got an alarm clock from goodwill and took it apart and am probably going to use the display for some tests. Here is a picture of the front of the display:

enter image description here

  1. The text on the left is YC-60525S 3
  2. The text on the right is 94HB
  3. On the back is WS6055 L S and 0306

Here is the display schematic I made as a PDF.


You will notice that pins 23-29 were never connected to the clock's other PCB; although pins 22 and 23 are soldered together. Also worth noting is that pins 7 and 8 are never used. And lastly a, d, e, f, and g do not currently function in any sense on digit 1 (hence '1' is the only digit it can make).

My problem is that I was messing around with the unused pins on the right of the board and managed to do a couple different things.

  1. I duplicated the controls Pin 1 had as ground to Pin 29 (Red/Purple in the PDF).
  2. I moved the majority of controls Pin 2 had as ground to Pin 25, leaving only control of the 1st digit to Pin 2 (Blue/Black in the PDF).

I am unsure what did to cause the board to change its configuration. I was trying to be pretty thorough labeling the pins, and at one point I brought in a second voltage line. I would like to know why/how this occurred, but also how I can then manipulate the boards settings to my liking.

share|improve this question
A photo and the mapped schematic you have worked out, might get you more useful responses. As you do not have sufficient reputation to post images to your question, please upload these to any free image hosting site, such as imgur.com or flickr.com, and provide the link as an edit to the question. Someone with edit privileges will incorporate the images into your question for you. – Anindo Ghosh May 16 '13 at 5:11
Looks like I got enough reputation by the time I went to edit for the picture! So there it is with the schematic; hopefully it helps focus the question. – Adam Dally May 20 '13 at 2:00

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.