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  1. M

    MEP-831a Inverter Overhaul

    Peter, Thanks for the reassurance re. the metal films...I initially had to verify the wattage since they just didn't look appropriate based on their size! Regarding the FREDs, the Vishay VS-E5PX3006L-N3 (30A) are TO-247 packages, so I will try sending them back and install the...
  2. M

    MEP-831a Inverter Overhaul

    Sorry for the "radio silence" - I've been awaiting parts and therefore had nothing to report until now... ...the 30 amp diodes as well as the 2w 65k Vishay resistors arrived from Mouser. Both raise packaging questions: I read somewhere that a metal-film vs. carbon resistor-swap leads to a...
  3. M

    MEP-831a Inverter Overhaul

    Peter, that is correct:
  4. M

    MEP-831a Inverter Overhaul

    Peter, Apparently this is it...B2040. So manufactured the 40th week of 2020? Thanks, Marcel
  5. M

    MEP-831a Inverter Overhaul

    Peter, I just checked two of my new Nichicons on a Snap-On tester (non-ESR). They confirmed the values I got using my Chinese tester...the two new Nichicons measured 480uF and the original Panasonic came out at 500uF. Given they are supposed to be 560uF +/-20%, the 80% value would be 448uF...
  6. M

    MEP-831a Inverter Overhaul

    Peter, just for grins I took a sample of four of my new replacement Nichicon 560uF electrolytics and measured them using my Chinese capacitor tester. Guess what they each measured? 480uF! :( I think this tester is junk. I'm going to bring them into work tomorrow where we have a proper...
  7. M

    MEP-831a Inverter Overhaul

    20 mili...it goes from 2000 pF-->2 uF-->20 mF in ten steps. Done it. I wasn't able to change my order to the 30A FREDs since Arrow mysteriously sold out overnight, so I ordered them thru mouser along with the metal film resistors. I'll just return the 15A FREDs after they arrive. Thanks...
  8. M

    MEP-831a Inverter Overhaul

    The range goes up to 20mF. I've been scouring the internet for 65k 2w ceramic resistors, and they appear to be unicorns. How critical would the value be (62k and 68k readily available)?
  9. M

    MEP-831a Inverter Overhaul

    Silly me! When I started measuring them and they all came in around 500 I completely forgot they were supposed to be 560uF and not 500. To be consistently off by on average 12% is in itself interesting. Maybe a dry 560 becomes a 500 - in which case they even fail the same way??? I will...
  10. M

    MEP-831a Inverter Overhaul

    Thanks Peter! I think I'd make the resistor bands to be blue, green, orange, and gold. Green could be brown, but I doubt it...In any event, I'll verify once pulled from circuit mid-week when other parts arrive, I've ordered the caps and diodes from Arrow Electronics, which is my primary...
  11. M

    MEP-831a Inverter Overhaul

    THE STRIPPER IS ON THE WAY! I thought I'd make my morning post sound like fun...speaking of which - I'd had more fun in H.S. detention! Those electrolytics were a PITA to pull. I think I'll wait for the stripper to arrive before I attack the diodes and ceramic caps...I am still trying to...
  12. M

    MEP-831a Inverter Overhaul

    I will see whether I can change the FRED order to the 30A version (VS-E5PX3006L-N3). They are a bit slower, but not by much. Thanks!
  13. M

    MEP-831a Inverter Overhaul

    Peter, I like it although I wouldn't know where to start to implement it! Sticking to the basics, I've sourced a sh*tload of Vishay S103K75Y5PN65K0R caps to replace the Hitano garbage as I pick through the rebuild. I also ordered replacement Vishay 600V 15A Hyperfast FREDs just in case the...
  14. M

    MEP-831a Inverter Overhaul

    That datasheet is for the high-frequency (30-60kHz) version, this is the one I have. Thanks
  15. M

    MEP-831a Inverter Overhaul

    Peter, No rush at all - I'm just grateful for yours and Kurt's support. I've gone ahead and ordered a NOS IGBT module just in case. I figure while I'm in here I might as well replace anything which appears suspect (or could be), and hope for the best. I kind of regret having sourced the...
  16. M

    MEP-831a Inverter Overhaul

    Peter, by power semis are you referring to those 14-pin ICs that are on the control board (BBQ'd on Kurt's board)? Or are you referring to the power transistor module? BTW, I hadn't paid much attention to it, but when I examined the terminals which shared traces with the failed ceramic cap, it...
  17. M

    MEP-831a Inverter Overhaul

    Peter, not sure what you meant by your statement above... ...do you mean that the diodes appear to be ok? Why did all diodes on the unburnt side measure OL (eventually) in reverse-bias direction, whereas those on the burnt board (missing the peg-legged ceramic cap) measured 1V in...
  18. M

    MEP-831a Inverter Overhaul

    I had to pull a few diodes out of their lake of resin before I could make out the markings...looks like they're good 'ole Japanese IXYS DSEI12-06A FREDs. I assume by power transistor module, you are referring to the component in the second image? If so, it too is reliable Japanese (not...
  19. M

    MEP-831a Inverter Overhaul

    Peter and Kurt, I am so grateful for your assistance with this project! I am a mechanical engineer by education, but unafraid of electrical work - which often leads me beyond my knowledge/understanding. Nonetheless, I am happy to learn. I tested the diodes in-circuit on both sides of the...
  20. M

    MEP-831a Inverter Overhaul

    The front and back-side of the board where it was soldered...
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