W A R N I N G !

W A R N I N G !

This page is full of non-facts and bullsh!t, (just like the internet and especially forums and other blogs), please do not believe entirely without exercising your intellect. Any resemblance to real things in reality is purely coincidental. You are free to interpret/misinterpret the content however you like, most likely for entertainment, but in no case is the text written on this blog the absolute truth. The blog owner and Blogger are not responsible for any misunderstanding of ASCII characters as facts. *cough* As I was saying, you are free to interpret however you like. *cough*

Saturday, March 31, 2012

Xonar Essence STX measured current draw on molex connector

5V: 0.48A
12V: 0.20A

1) Each rail is measured while the other is left unconnected. It is possible that current draw might be higher if both rails are connected.
2) Does not include power drawn from PCI-E slot.

Hmm, why do I need this info? ;)

And did I say STX? ;)

Saturday, March 24, 2012

Badly-designed cheap product strikes again

I opened up this portable speaker with the intention of converting into a passive one,

It is a mono speaker that accepts 3.5mm stereo input. I couldn't see clearly the different solder joints for the red and white input wires, so I looked at the bottom of the PCB,

And I realized that I didn't see wrong, the red and white wires are indeed connected together. A quick check by the meter confirms it to be the case.

Pardon the zero error of the cheap meter.

Would it have cost them too much to include two more resistors? Luckily I haven't connected it to a headphone amp, or I'd be even more mad if something of mine did spoil.

Zhaolu D1.3 headphone amp section RMAA

Because why not.

Saturday, March 17, 2012

Obvious over-rating is obvious

I was looking at 12V "industrial"-type power supplies, may be useful for mITX builds.

There was one being sold rather cheaply for its output power.

12V, 10A.


Input current: 1.1A @ 115V

Hey... that's only 126.5VA.

I can let it have 99% power factor, possible in this day and age of active PFC, but over 90% efficiency for an AC to DC power supply so cheap? Not likely.

So this thing is obviously incapable of sustaining 120W continuous.

If you observe, a good power supply's (input voltage x current) in VA (volt-amps) is much bigger than its rated maximum output power in watts, in some cases more than twice as much. So this can be a good way to see if the company is padding their ratings.

Sunday, March 11, 2012

Sirius LCD repair part II

Back in Dec 2009 I repaired a Sirius LCD TV. This thing uses Teapo/cheapo (Japanese probably pronounce it that way) caps in multiple places. When I bought the replacement capacitors I forgot to check the temperature rating and bought new ones that are lower than what the Teapos are rated, so instead of all the capacitors I just replaced the single one that has obviously failed. It brought the TV back to life so I just left it like that.

Despite the lower temperature rating for a capacitor placed right next to a heatsink, the capacitor lasted more than two years.

A few days ago, the TV finally decided to go psycho flickered the backlight vigorously. I feared for the backlight and its inverter, because if either of them is dead it is virtually impossible to repair or replace.

Checked the power supply nonetheless. On first inspection nothing seemed out of place. But many times a capacitor can appear fine (no bloat, leak) but the inside has dried out. And these are Teapo caps. So I proceeded to change them anyway.

And after removing the capacitors, the cause of failure became clear -

Yupz, capacitors can pop from the bottom too, and it's hard to see when you're usually viewing from the top.

The ideal thing is to order new parts fit for the job, but today is Saturday and I need to know if the TV can be repaired like now so I know if I need to buy a new one. So I dumped the 1000uF 35V Panasonics that I have lying around inside.

At the same time I also removed the previously installed Panasonic and went totally overkill - Rubycon ZLH 2200uF 25V, bitch. If this (10000 hours @ 105°C and more than double capacitance and voltage ratings) doesn't last I dunno what will.

Problem solved, lets see how long this TV can last.

Thursday, March 8, 2012