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| HP 8153A Lightwave multimeter - does not power up |
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| asilva10:
I have a HP8153A that does not power up. I was not able to find any schematics or service manual for this instrument. I made quick measurements at the power-supply board (HP P/N 08153-66503) and it seems that the input stage is okay and after the rectification I have +165V (input 110Vac). But after the switching stage, no voltage level. I cannot detect any sign of "oscillator on". I believe that the driver is a component Q101, but I am not sure. I tried to look at eBay and found a lot of these instruments with the same problem (no power). Any hint? |
| Jwalling:
There's a 8 pin DIP that controls the switcher, I forget the part #. Replace it and you'll be good to go. I've fixed at least 10 of these in the past where that chip was bad. |
| asilva10:
@Jwalling - thank you!! Yes, I found: TDA4605 - a switching controller - it must be this guy!! I will let you know. Thanks! |
| asilva10:
Problem solved: put a 8-pin DIP socket and installed a new TDA4605. Everything working now !! |
| Jwalling:
--- Quote from: asilva10 on November 02, 2018, 05:55:27 pm ---Problem solved: put a 8-pin DIP socket and installed a new TDA4605. Everything working now !! --- End quote --- For some reason, the chips made in Austria have a high failure rate. |
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