Re: List of Bad Cap Manufacturers

Found something interesting. WS brand caps in a cheap power supply, marked as 200V 470uF. On the tester, one shows 216uF and the other 220uF! So I guess they just relabeled 220uF caps?...

Re: Need help identifing component

I'll second that, go with a whole new module.

Just for reference on other projects, SMD oscillators and some crystals both use 4 pins; one is basically a passive component while the other is powered and actively generates a signal. From seeing a few datasheets, there doesn't seem to be a reliable way to tell them apart by looking at them. What you could do is look at the board it was on, and follow the 4 traces (either by eye or with an ohm meter). With an oscillator, one pad will go to +5V and one will go to ground. Also they probably...

Re: Hickok 5055 bench supply restoration

OK Bob, will do.

Took some time, but I got the whole thing working.
There were 5 separate circuit breakers, all with rusty metal cases. They were acting a bit weird, when I'd reset them, they'd change the output voltage! Just had to take them apart and clean the contacts, all work well now.

In the limited information I found online about this supply, I noticed several people mention the big 25W 100ohm power resistor that runs very hot. Sure enough, I checked the voltage and mine dissipates 21 watts of...

Re: Hickok 5055 bench supply restoration

Hey Bob, I attached some pictures of that board. It's pretty cramped in there. Let me know if they're not clear enough, would be easy to draw up a diagram next time I work on it.
The single wire on the back of the board goes to the (-) lead of the nearest big cap.

I'm wondering if a couple parts on mine are fixes or addons. Can you check yours for the two three-terminal devices pictured? One is on the inside back of the chassis, the other on the side.


Ben:

Ok thanks I will give it...

High Nick. I have the 5055 supply also. I could use a closeup of the 40 volt board showing hookup of the wiring harness. The other sections function properly. I did replace all of the large cap on my unit. If you can help me I would greatly appreciate it. Thanks Bob

Alright, so I just picked up this old power supply from a scrapyard. This thing is from the mid 70's and has been out in the elements for probably 2+ years. The AC cord has been cut off of it, which is probably for the best for the time being..
I'm attaching some pictures of the interior, there are a few caps that look like they're leaking. They're an old style so I'm not positive if that's what it is. I found an old thread about this supply that recommended replacing all of the big caps:
[url]https://www.badcaps.net/forum/showthread.php?t=11043[/url]
Are they worth...

Re: Help with identify part

That specific package is used almost exclusively for MOSFETs and diodes in compact power supplies and laptops. Since it is far away from the transformer output, I'd rule out diode.
See if the similar device to the left of the blown one is readable, it's probably the same part number as it.
If it isn't, you could try any N-channel MOSFET in a TO-252 package that has 30V+ Vds rating and a low Rds On (<50mOhm) An example part # stocked on Mouser is SQD50N04

Re: New Members - please post your introductions here

Hey, I'm Nick. I'm 24 and I've been messing around with electronics since I was a kid. Mostly I tear down broken stuff and build simple circuits from the parts, but lately I've come across some more interesting gear that I'd rather repair.
So I figured I'd register here to get some advice. I'm no expert, but maybe I'll be able to help others out too.