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  1. dorke

    Technics SA-828 - Static with audio, then stopped working

    Yes the bridge is fine. What you should do is assemble back all parts removed. Disconnect all speakers from the unit. disconnect all inputs from the unit. Then power it up,and put the volume at minimum. Does the relay click? At this stage we can do some voltage measurements in order to locate...
  2. dorke

    Technics SA-828 - Static with audio, then stopped working

    No, 0.9 is a reading of 2 diodes in series ,this is not the way to test properly. You should test each individual diode twice reversing polarity. You should get : about (0.5-0.6) and O.L for each diode.
  3. dorke

    Capacitors

    Welcome to EP. You are making a fruit salad of it all...;) 1. "What a Farad is?" It is the unit to measure capacitance. It tells us what is the maximum electric charge that can be stored in a capacitor. It can be imagined to be the size of a "reservoir" i.e the larger the capacitance(in...
  4. dorke

    Technics SA-828 - Static with audio, then stopped working

    It is actually 25% ....but even 50% means re-adjustment is a must ! About the bridge testing: The way you did it is partial . You need 8 measurements to test it properly ,2 for each diode.
  5. dorke

    Need help with pcb repair

    More information including pin numbers and the numbers of connected parts and there pin number is required. This info should be found in a detailed schematic, take another look and identify the part in that schematics.
  6. dorke

    Need help with pcb repair

    Can you read the part number of the IC on the PCB?
  7. dorke

    Need help with pcb repair

    Welcome to EP. That is heavy damage. You probably don't have the right tools/knowledge for this kind of repair:( What tools are you using? The problem isn't the pads themselves ,rather it is the conductor they should be connected to. Since a Laptop is a multi-layer PCB, I think it is probably...
  8. dorke

    Technics SA-828 - Static with audio, then stopped working

    It is nice that you have a DMM and scope,they will both be very handy. The problem with the Tr's you have pulled out is with the TO-220 types , those that are on the L-shaped heat-sink. Unless you have marked which channel they came from(did you) you will need to adjust both channels ! Yes...
  9. dorke

    Rotary Switch

    Hop, Agree with you tuning of transceivers is the easiest with an optical encoder. Long long ago I worked with some WJ receivers and later on with iCOM receivers which had great rotary encoders for tuning + a button to select the "digit of tuning"and a number pad for direct frequency entry.
  10. dorke

    Rotary Switch

    Hop,yes he can. But looks like @Sadlercomfort wants to be flamboyant in his project. Or maybe,It may be a project requirement to use a rotary switch. I still think a momentary push button is the way to go, total software controlled,simplest and cheapest . Say like: Short push/release to...
  11. dorke

    Technics SA-828 - Static with audio, then stopped working

    Welcome to EP @darryl603 If I understand correctly you have one Good Left channel and one Bad right channel before removing parts? I see you removed parts from the good channel and common parts(like the bridge rectifier,this makes no sense to me. Removing parts for testing isn't normally...
  12. dorke

    Rotary Switch

    What you need is called "Incremental Encoder". You can actually build an optical one yourself just for the fun of it, Opto Transmit/Receive and a slotted rotating disc( slots can be less than shown ) .
  13. dorke

    Rotary Switch

    Yes, you do need to define your requirements before you can select a switch. Will this switch be the only one used? In what manner? etc.
  14. dorke

    Fluke 123 Scopemeter Not Working

    You are most welcome,good luck with the repair. If more help is needed we are around;)
  15. dorke

    Rotary Switch

    Here are some links that may help you: Poles and Throws In rotary switches Angles BTW, you can use a simple momentary SPST push button for controlling menus. They are much smaller and cheaper.
  16. dorke

    Fluke 123 Scopemeter Not Working

    Yes, I agree you should use the correct S.M for the repair. When you do have it, use the power up circuit and sequence to find what went wrong. Also notice, there is a "rest to factory settings " procedure you may need to try. Let us know of your findings.
  17. dorke

    Parts Identification

    Agree with Adam on the resistor array(1K ohm). The green one is most likely an SMD fuse. It is in series with pin 1 of the USB connector , the +5V output. Probably 5 for 0.5A.
  18. dorke

    Fluke 123 Scopemeter Not Working

    As I said I'm not familiar withe the Fluke 123. With 3V battery voltage, no wonder the unit doesn't work-it should be 4.8V nominal. Internal Battery Pack BP120 (Fluke 123): Battery Power Rechargeable Ni-Cd 4.8V(page 2-10) Is the charger charging the Battery? Please read paragraph 3.2.4 and on...
  19. dorke

    8051 power supply

    If the current needed is less than 500mA , you can power it from a USB PC port.
  20. dorke

    Fluke 123 Scopemeter Not Working

    Welcome to EP. I'm not familiar with the "Fluke 123 Scopemeter" Fluke has 3 different service manuals on their web site : 123 Service Manual . 123/124 Service Manual. 123/124/125 Service Manual. Which one relates to your specific unit ? In general, operating units with external adapter...
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