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  1. dorke

    Help! Repairing water damaged PCB from Massage chair.

    One thing we did not do and need to is checking the motors themselves. Please do a resistance/ohm test of all the motors. Can you please note them on the "full back of the chair photo" like so: 1.Name of the connector they are driven by on the main board. 2.Motor type: AC(and value of capacitor...
  2. dorke

    Help! Repairing water damaged PCB from Massage chair.

    O.K I think a local dealer may have a "service/repair center", worth trying. I think the last tests confirm that the IC is indeed partially bad. We can go on fixing the chair without the IC, later today.
  3. dorke

    retrieving codes from OBD2 with oscilloscope

    The tool(aka scope) you have is not intended for this kind of job. What you need is an OBD2 "protocol analyzer" with the correct hardware interface. The protocol is bidirectional: i.e the "reader"(you) tells the "car" what you want it to do for you by sending a "command" to which the "car" will...
  4. dorke

    Little help: Pool for 3 project design ideas

    "whichever you think its the best for now". In what way are they suposed to be best? "project proposals" What is the scope of this project?
  5. dorke

    searching the internet for 10-20 national semiconductors LMP8100

    Sadly not entirely so. They do deliver cheap parts, but fakes are too common...:(
  6. dorke

    searching the internet for 10-20 national semiconductors LMP8100

    Here
  7. dorke

    retrieving codes from OBD2 with oscilloscope

    Theoreticaly you can. Would you try to chop down a tree with a kitchen knife...;) Get the right tool for the job! Buy an obd2 scanner, they are dirt cheap.
  8. dorke

    Help! Repairing water damaged PCB from Massage chair.

    o.k So the IC is probably bad after all. Did the motors work when you could make the relays click with the remote(before inserting the short-wire)? Please repeat the tests you did on #204 ,this time with the IC in the socket (measure on the IC legs). Did you hear anything from iRESET ?
  9. dorke

    Help! Repairing water damaged PCB from Massage chair.

    That is great news! It gives hop that the IC is not bad after all. Time to check the clicking of the blue relays with the remote. Insert the IC back without power and the correct direction(pin 1 mark). Connect the main and controller boards the limit-opto boards and the remote. Do not connect...
  10. dorke

    Help Identify the component

    Martin the issue is much more complicated. for example see here CHARACTERISTICS OF MOV FAILURES
  11. dorke

    Help! Repairing water damaged PCB from Massage chair.

    Bed time,so here is the last for today: Next step is to measure at pins 39,40 with/without blocking the light through the WidthA/B opto devices(which is which?). What do we get?
  12. dorke

    Help! Repairing water damaged PCB from Massage chair.

    Just to clarify things about pins 37 and 38. 5V when opto light isn't blocked and 0v(what voltage exactly?) when it is blocked. or is it the other way around?
  13. dorke

    Help! Repairing water damaged PCB from Massage chair.

    12V isn't a good thing, did you mean 5V?
  14. dorke

    Help Identify the component

    Well, MOVs(Varistors) are connected in parallel to the circuit that needs protection from over-voltage surges. I guess series connection application can be found, but the overwhelming majority of their applications are parallel. Mostly between Live and Neutral. But ,Live to ground and Neutral...
  15. dorke

    Help! Repairing water damaged PCB from Massage chair.

    Well, Since there is no 12V on the opto boards ;it is clear they will not work. We have to repair that by inserting a jumper wire(resistor leg etc.) near CN35(blue on the photo below ,insert it on the Component Side and solder it on the PS) to supply the 12V. I know you started without the...
  16. dorke

    Help! Repairing water damaged PCB from Massage chair.

    Well, The 0.35V you measured on pin-34 is fine,it is expected for that pin. Besides,it has nothing to do with the optos limit boards. Let's not get distracted... Can you please complete the tests/info on #195.
  17. dorke

    Searching part number for 690KE

    It is the same manufacture. G690/691 is a family of reset parts with different "logic" and a variety of "trip levels" and slightly different packages.(see the table below). The "K "-suffix part makes perfect sense to the circuit of the op. The strange thing is what went through GMT minds to...
  18. dorke

    Searching part number for 690KE

    Well, We are getting close, but no cigar yet ;) I think your device is G690H438Tx from GMT(a Taiwanese company). (Look at page 5 on the datasheet) The marking isn't exact(they may have changed it to the more logical 690 from 688.... ) ,the best would be to contact them and inquire here here...
  19. dorke

    Serious lead-acid battery charger

    Probably a large truck battery. @Orefat , It isn't the simplest of projects out there, why won't you use a commercial one?
  20. dorke

    Help Identify the component

    No, the other way around: MOVs are connected in parallel to the circuit they need to protect. Thus an open MOV is an open parallel circuit, no current flows through it, and it does not "direct current away" . It is bad practice to leave damaged parts in a circuit as they are no longer...
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