point of interest i recap my 14years old djm800 psu.last 2-3 months gets too hot the mixer on psu side.open it after two hours of use and touch the big filter cap and the near mosfet heat sink was very hot.under the board i see three hot spots that is discolored from excessive heat. replace all caps with nichicon GU big filter cap and all the others with nichicon KY and panasonic FR now is running cool and sounds better.
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Hello All, I have on the bench a couple of PSU's which have some failed Nichicon PL series caps. They didn't "puke" their guts through the top, but instead "diarrhea'ed" corrosive brown electrolyte through the bottom, down the legs and onto the board. On one cap, the electrolyte rotted the cap right off the board leaving 2 little stubs, and also corroded a trace on the foil side.
The PSU's are Power-One MAP series and are ringing-choke topology. The semiconductors have date codes in 1993. The PSU's were used in a commercial application, fan-cooled. They had failed... -
Normally, I never post repairs this quick after I do them, because… I am usually very slow.
But today, I’m making an exception here. Why? No idea. Perhaps only because the repair details are still “fresh” in my head… which is ironic, given this is a 16 year old monitor that hardly anyone will care about today. It is new to me, though. 
I picked it up last November from someone on my local Craigslist. It wasn’t very close to where I live, but was close to a family friend that I had to go visit anyways. So after watching the posting on Craigslist for a few weeks and seeing it getting...
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I recently acquired a set of Bose Roomate speakers from the mid to late 80's. Basically the right speaker cabinet is completely passive, and the left one has the power transformer and amplifier circuit in it. Out of curiosity, I opened it up to see what the circuit looked like. Looks like they used all Nichicon VX (2x 4700uF/16v for smoothing off the bridge rectifier), a couple random Nichicon SE series sprinkled on the board, and what really caught my eye - 2 yellow sleeved Nichicon caps (both 1uF/50v with no real series marking. Below are pictures of the caps. The only thing not shown in these... -
Mounting and Handling Guidelines for TO220 TO220F TO247 Cases / Packages
The TO220, TO220F and TO247 are the popular packages for power devices because of their versatility and ability to dissipate moderate amounts of heat. This application note describes the basic guidelines for handling power MOSFETs in TO220, TO220 and TO247 packages shown in Figure 1. Please note that only mechanical and soldering guidelines are covered here. Additional precautions are required for isolating high voltage rated devices to meet safety regulations.
Securing a good thermal interface between...10-07-2024, 04:35 AM -
Hello,
I have a Pioneer VSX-D902S receiver that I am trying to replace the 2 large 8200uF 80V filter capacitors on.
I have already removed the capacitors and ordered replacements, but I made a mistake in ordering. The original capacitors are Pioneer ACH1202 80v 8200uF and have 4 pins. The capacitor replacements I bought are Nichicon 80v 8200uF and only have 2 pins.
I was wondering if I could still use my replacements even though they only have 2 pins. Obviously I'd have to extend the pins of the capacitor to allow them to reach and fit through the...