Re: Polk Audio RTi100 Plate Amplifier won't power on and intermittently honks and buz

[B]First update:[/B]
I looked into this a bit more and it turns out that it is NOT the transformer that's buzzing -- which is good news -- as that part would seem to not be replaceable.

[B]Second point:[/B]


Good observation. I'd just assumed that it was installed a bit crooked. However, while trying to narrow down what component was buzzing I poked at the tilted capacitor and noticed that the lead on the raised side is completely detached from the capacitor....

My childhood best friend was killed about 9 years ago. His parents are finally letting go of his things, and they offered me his Polk RTi100 tower speakers. The Polk RTi100 towers are one of a handful of designs from the early 2000s that is a full range 3-way tower with a built-in self-powered subwoofer. This is accomplished with a plate amp integrated into the speaker input panel.

I think they used them for a while, but they've been sitting for at least a few years now. After about 40 hours of driving to their house and back (both they and I have moved in the last 9 years) I got...

Re: Replace Multilayer Ceramic Capacitor on Asrock Z97E-ITX/ac

Back when I was initially thinking that the require capacitance was more like 100uF, it seemed obvious that I'd need a Class 2 MLCC because Class 1 MLCCs wouldn't have that high of capacitance at the required voltage and dimensions... but now that I'm only looking at 10uF so both Classes are available.

According to the wikipedia article:
Class 1 ceramic capacitors offer high stability and low losses for resonant circuit applications.
Class 2 ceramic capacitors offer high volumetric efficiency...

Re: Replace Multilayer Ceramic Capacitor on Asrock Z97E-ITX/ac



Right on the money!!

Short version:
Pulled off a cap and it measured right at ~10uF (10.2-10.3uF measured).

Long version:
I desoldered one of the caps, and then while trying to get the leads of my multimeter onto it with enough pressure to make good contact... it shot off onto the floor and disappeared forever. Since I'd probably killed the board anyway by removing a 2nd cap, I went for broke and pulled another one off and by being more careful was able to get...

Re: Replace Multilayer Ceramic Capacitor on Asrock Z97E-ITX/ac



With the board powered up, I'm reading 12.2V across one of the still connected caps by poking each side of it with my multimeter. It would appear that these are probably for input side filtering. The 12.2V reading is due to the pretty low end PSU I'm using on my test bench. Since the ATX spec allows for up to 12.6V, I imagine I'd want to get at least a 12V +/- 10% cap or one for 13V+ to avoid sending too high of a voltage through it.

As oriented in the attached picture, the left-hand pad for...

I initially posted this as a [URL="https://linustechtips.com/main/topic/1230959-replace-multilayer-ceramic-capacitor-on-asrock-z97e-itxac"]thread on Linus Tech Tips[/URL]. I got some feedback, but not really to a level that gives me confidence in my next steps. Then I remembered about this forum that I'd used as a great reference for recapping an amp so I figured I'd reach out here. My question below is a combination of my original question as well as all of my findings in the other forum:


I just received a used Asrock Z97E-ITX/ac board that I purchased on eBay. According...

Re: New Members - please post your introductions here

Hi everyone!

I'm into computers, home theater, and cars. I work at a small computer software company doing software design and QA - though I don't really write any code.

My passion is computer hardware though I've never done anything as low level as recapping a computer board. But computers are not why I'm joining here today. Once I'm done with this introductory post and I have some time I'll be writing up a "HELP ME!!" post in the audio section (don't worry I'll provide lots of details and...