Re: Ceiling Fan Capacitor

Thank you. Sorry, I was not aware of inclusion of interference protection.
There is a second block labeled 4L (photo attached). Would that be a run capacitor? Do you know what 4L indicates?
The subtle noise seems to me to be excited by motor magnetism as far as I can tell. It spins very free by hand and has no wobble....

Perhaps someone could provide some direction.
- Ceiling fan, 25 years old, used 2/3 of every year but very clean.
- Temps dropping so I shut it off one night.
- The next day, after starting it the motor area began producing a subtle but strange noise that I can only describe as imagine two Phillips head screwdrivers and occasionally one of the screwdriver shafts slides down the other (a clean metallic scraping). The repetition is random. Only happens wen the motor is running (the bearings are fine). I tightened all mechanical components.
- Then the medium speed (the...

Re: Industrial 24 VDC PS troubleshooting

Raising the temperature of C9 & C16 allows the switcher to start on the bad power supplies.

Many thanks to you guys !!

Re: Industrial 24 VDC PS troubleshooting

STJ & Per Hansson, thank you for your advice. I'm grateful to learn caps & sometimes a couple of resistors actually start the switcher (I did not know this, thanks). Also, good idea on increasing the temp of some of the capacitors, the SMT heat gun that I have has nozzles to where I can focus the heat stream. I'll follow with the results. Much appreciated.

Re: Industrial 24 VDC PS troubleshooting

Thank you for your responses !!
I attached an 8 page PDF with additional photos & measurement points.

When I compare measuring components and voltages between one of the good & bad power supplies...I don't think that I see a single discrete component that measures bad (in comparison).

I realize that I could be off base but please let me share my (mostly anecdotal) thoughts...I'm somewhat suspicious of the TL3843b PWM controller is failing on these power supplies. Part of my logic is these hundred...

New to the forum...
The Power Supplies I'm having trouble with is branded under different brands (Rhino PSC-24-090 or Traco TBL 090-124) but I think the actual mfg is Convertec 090PSL182/E out of a factory in China. We have hundreds of these installed, and have operated flawlessly for many years. But suddenly there is no 24 VDC when the AC power is cycled. I was hoping that someone in the forum may have access to a schematic or is so knowledgeable about power supplies, could help me to better understand this power supply. Please refer to the [PSC-24-090 Top View Photo.JPG] and [PSC-24-090.PNG]...

Re: New Members - please post your introductions here

Still trying to insert my first post but permission not yet granted. I'll try to post another intro post here and return to the 'Troubleshooting Power Supplies and Power Supply Design' to insert my first post.

Re: New Members - please post your introductions here

Hello, new member, need help troubleshooting a 2v VDC switching power supply. I will now post the details to the appropriate 'Troubleshooting Power Supplies and Power Supply Design' forum, since sending this initial intro post is required. Thanks