Re: Tektronix 2215, pulsing/chirping noise, no trace.
Alright, I've tinkered with it some more and I feel like I am gettingtoggle quoted messageShow quoted text
close. I measured the caps and checked some for shorts (I straight up
removed the Rifa caps) and they seemed fine. The diodes also seem fine. I
decided to take a look at the Q933 MOSFET, and decided to check for a short
there, as I hadn't checked for a short after the rectifier. Lo and behold,
0 Ohms to ground at the source. Suspicious! I started checking all
components going to ground thru the FET, and none of them were shorted
after desoldering them. About halfway through this, though, I decided to
take a *short*cut. (Pardon me.) I fed in 5V limited to 1A with my PSU from
the source to ground, and checked which component got hot. And it was T933!
Unfortunately I ran out of time so I'll desolder and check the transformer
when I get back to the scope on Friday. I also suspect U920 might be dead,
so if I can buy a replacement at my local components store I'll get one
just in case.
El jue., 11 jul. 2019 a las 16:00, <tekscopegroup@...> escribió:
Most switching power supplies need a load on the output to be able to