Search results

  1. felto

    Slotted Optical Switch

    but can I test the leads just like I would test a diode?
  2. felto

    Slotted Optical Switch

    Thanks Do you know how to test a voltage regulator? I have a 7812CT 3-pin voltage regulator and I think its bad. Can you tell me what pins are what and how to test it with a voltmeter? Its for a multiprinter gizmo and when I hook up the power it sparks back and I get no juice from it...
  3. felto

    Slotted Optical Switch

    Has anyone ever heard of this switch? It looks like a 'U' shape and has four terminals to it soldered to the circuitboard. In between the 'U' shape is a grove where something blocks the optics and I guess that it turns it on or off. My question is does anyone know how to measure this with a...
  4. felto

    Need help with hpofficejet 4215

    That has something to do with your phone line that needs distintive device so that your fax can understand your phone line when it is sending a fax. Look into your phone modem options in control panel and there should be something in there about distintive ring. I think you should check that...
  5. felto

    Need help in fixing lexmark printer

    Hi all, Can anyone help me in fixing my lexmark printer? I have a multiprinter type (scanner, fax, print) and the problem is in the main circuit board of the printer. When I connect the power cord I can see a spark from the connection but I get no power to the unit. The board does not have...
  6. felto

    Chip Identity?

    So if I wanted to order the TA75393AP chip where would I get it?
  7. felto

    Chip Identity?

    Thanks MP for that info. Where did you find that info I went to embeddedlinks.com (chipdir) and couldnt find anything there. Is there another website that you know about? Thanks again
  8. felto

    Chip Identity?

    Does anyone know what this chip is? I am trying to find the schematics of it but cannot find anything on it. It looks like a 555 timer with 8 pins to it. But it doesnt say anything like that. Does anyone know a website or a databook that they may have and can look up the schematics for me...
  9. felto

    Electronics Now--Back-iisue

    Yea thanks can you scan some of those EPE magazines and forward them to my email [email protected] thanks again
  10. felto

    Logic Gates IC Chips

    Thanks Kevin. Hey Kevin how would you test an 'AND' gate chip with a voltmeter?
  11. felto

    Logic Gates IC Chips

    Thanks for your help How would you test an OPAMP? for ex. the LM324
  12. felto

    Logic Gates IC Chips

    So what your saying is just hook up the 5 volts to the chip and I would see a 1 and 0 at the input then with my voltmeter I would see a 1? Where would I hook up the voltmeter? positive to the output and negative lead to ground?
  13. felto

    Logic Gates IC Chips

    sorry but I dont follow you exactly. I have to remove the chip from the board? or can I just plug the board in and use that source? How do I establish the highs and lows? How do I know when one input is high and the other is low or both? can you tell me exaclty how to wire it up. Thanks for...
  14. felto

    Logic Gates IC Chips

    Hi all I would like to know how to test the logic gates of an IC chip, for instance a 'NAND' gate or an 'AND' gate in a circuit with my voltmeter. I do not have an oscilloscope but my voltmeter is capable of reading the highs and lows of the logic gates. Where do I need to hook up the leads...
View older results
Top