Hello.
To continue my learning experience here, I've bought an Oscilloscope and am slowly learning how to use it.
I've tested several new, recapped and still functional PSUs with mixed results and a bit of perplexededness on my part...
But I hadn't tested a truly bad PSU. You know the kind.... one with the hatching Fuhjyyus still inside.
Well, I recently had such an opportunity! I won a $5 PSU on eBay, described as Old, but still works. So it got here the other day. It's an ancient HEC 300AR.
I took a peek inside and.....
a vented Fuhjyyu!
Primary caps are CapXon and secondaries are Fuhjyyu, CapXon and Per-mar? I think.
Plug it in, jumper the green wire and Blooey! Well, OK, a loud ominous hissing sound with lots of smoke coming out of a ruptured Fuhjyyu 2200uf/16v which ended up being on the 12v rail. I didn't want to run it for more than a few seconds at a time so I only scoped the 12v. Ripple was way over 700mv! Oh, just call it a volt!
So just for educational purposes, I took it apart and put in some Nichicon PW and Rubycon MCZ. Oddly, the 5v rail had 3 caps on it, a 3300 and two 1000uf all on the trace with the red wires on it. 3.3v had a single 2200 on it and 12v had one blowed up Fuhjyyu 2200/16.
Put it all back together and..... No more smoke! 12v Ripple at 60-70mv only because of some weird wavyness, otherwise it looks like around 20mv. (idle) 3.3 and 5 v also at 50-60mv without the wavyness.
The PSU itself is quite heavy with all of the input filtering stuff and an actual bridge rectifier. The heatsinks and attached transistors and stuff are plenty big as are the choke coils. The fan appears to be temperature controlled and is very quiet. This looks like an old Antec.... plenty sturdy but cruddy capacitors in it. Now I've got just the PSU for any PII or PIII system that might stroll in!
Have fun!
Keri
To continue my learning experience here, I've bought an Oscilloscope and am slowly learning how to use it.
I've tested several new, recapped and still functional PSUs with mixed results and a bit of perplexededness on my part...
But I hadn't tested a truly bad PSU. You know the kind.... one with the hatching Fuhjyyus still inside.
Well, I recently had such an opportunity! I won a $5 PSU on eBay, described as Old, but still works. So it got here the other day. It's an ancient HEC 300AR.
I took a peek inside and.....
a vented Fuhjyyu!
Primary caps are CapXon and secondaries are Fuhjyyu, CapXon and Per-mar? I think.
Plug it in, jumper the green wire and Blooey! Well, OK, a loud ominous hissing sound with lots of smoke coming out of a ruptured Fuhjyyu 2200uf/16v which ended up being on the 12v rail. I didn't want to run it for more than a few seconds at a time so I only scoped the 12v. Ripple was way over 700mv! Oh, just call it a volt!
So just for educational purposes, I took it apart and put in some Nichicon PW and Rubycon MCZ. Oddly, the 5v rail had 3 caps on it, a 3300 and two 1000uf all on the trace with the red wires on it. 3.3v had a single 2200 on it and 12v had one blowed up Fuhjyyu 2200/16.
Put it all back together and..... No more smoke! 12v Ripple at 60-70mv only because of some weird wavyness, otherwise it looks like around 20mv. (idle) 3.3 and 5 v also at 50-60mv without the wavyness.
The PSU itself is quite heavy with all of the input filtering stuff and an actual bridge rectifier. The heatsinks and attached transistors and stuff are plenty big as are the choke coils. The fan appears to be temperature controlled and is very quiet. This looks like an old Antec.... plenty sturdy but cruddy capacitors in it. Now I've got just the PSU for any PII or PIII system that might stroll in!
Have fun!
Keri
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