power point, good design until it's broken

Before I plan to continue my tweak story on my old Sony CD Player, lets us see this power point problems.

Like other people, I like to plug in those power cables to one hub. But beware of the rating. No more than 1PC and 1 LCD monitor, plus bunch of wall wart adapters. I bought this one some 4 years ago, no problems until now. I have selected this one from bunch of others.


Things I've looked from what was visible underneath the packaging :

• wire thickness or gauge, the thicker the better
• available ground connection (3 prongs connection), safety reason
• thickness of brass receptacle & ground contactor in the socket, for durability & contact firmness
• plastic housing quality, choose heavy one that easy to clean & does not change color

Conclusion: this power point is a good one!, good designed & made, it lasted 4 years

Just a couple days ago, the red lamp switch just gave up. It made a sparkling noise. That was no good for my daughter's PC and LCD monitor. In fact, the LCD went in to protection mode. No picture at all. One of the mains pin is melted..so I have to cut the cable & hiks...throw away the plug..sorry mother earth..


When I tried to replace the switch, it turned out that the manufacturer used special screws, that need a special tool to unscrew them. Well...screw the maker!..they just want us to throw away the thing & buy new one..no thank you..not me!..safe the planet you know?..

Here is what I do to open the case & replace the fragile switch (no lamp this time). Lamp gave heat, heat is the enemy of plastic..they went broken because of long time heat exposure.

I just cut the screw head with mini grinder wheel, along with plastic casing , just deep enough to create a thin groove for unscrewing, but still retain the screw bosses on the casing. The rest is history. This power point will go for another 4 years and I feel good saving it for the trash!


How about the design?.. Its good up to the switch durability. On the end product life cycle? such as design for servicing & for environment protection? I'll give the maker zero out of 10 for making us throw away things and buy another.

Sony CD Player Laser/ Optic change

Finally I have replaced the old optics of my very old Sony CDP950 CD Player. That is after many weeks of frustration due to weakened laser optic (type KSS150A). Many hours I've spent to adjust the small trim pot (just below the lens assembly, on the back side), tracking & reading is getting worse every time. Hmm, it time though to look for new optic. Asked around some shops..there are no KSS150A everywhere.

the kss150A

No wonder, this little guy is older than my daughter!!, bought around 1988, one of the second generation of CD Player. In one shop one guy advising me to use a newer type, the kss210, he is a honest man, told me that some player can be replaced some not..price? less than USD 4. What the heck, I'll try that along with a new disc motor with long shaft (mine is wobbly), availability is very good here. Old motor is made in Taiwan, the new one is Malaysian made.

old disc motor

Got home and soon the Sony is in pieces.., removing the motor you'll need to desolder the board. I've marked the + and the - of the motor. Next is removing the old optic assy & install the new guy. Whew..that was easy!. The new motor is also installed as marked in the PCB.

bottom view of tray

See the green board? That's the motor PCB. The right side motor is the tray motor, the middle one is the disc spinner. Just below is the optic, the one with wires and red connector. Here is the top view.
Also the variable output capacitors are replaced, see below.


Now comes another lengthy frustration, ...got everything re connected, turn the power on, put a CD..well it's spun very well..but, where is the music?..no reading?..no time on display?. Well..its might be not as easy as I've thought, I remember the shop owner words.

I noticed that the CDP main board has many trim pots, wonder what they do?. Before I tried to trim the pots I marked them. So I know their original positions. First the trim pot on the optic..no luck. Then the rest of the pots on the mainboard. Yes, they have some thing to do with the optic head & motor speed (the servo things!), still no luck..at 3 AM I thought I'll have to say good bye to my CDP950.., pity though, they have many quality components. Nichicon Muse & Elna Duorex electrolytic capacitors, nice resistors & ceramic capacitors, there are also high quality silver mica ones. And most important..the now sought after TDA1541 DAC/ digital analogue converter.

I thought I'll go to sleep then. The next morning I need to listen to some music (I'm still felt frustrated all right), I picked up a DVD player below our TV set, hooked & put a CD and..blah!!..the sound is very harsh, tiring to hear... I thought that some tweaks will tame this USD 20 player...I really missed my CDP950..

Again, the cheapo DVD is in pieces, changed the capacitors on the power supply board, they've used a switching one, with very small transformer. One capacitor near the trafo is bulbing on the top side, waiting to burst open..who to blame? Ok. everything is re installed, put a CD and hooked back to my system without top cover. Hmm..the CD sound's stabilized now..but WAIT!!..why is the disc turns the other way as my CDP950?, this DVD turns the disc clockwise viewed from front side...could it be?..that my CDP?..or this DVD is wrong..or?

I rushed back to the Sony, desolder the motor, marking is ok, + on PCB is + on the motor (red dot)..ok, now resoldered the other way around, + on PCB is - on motor, put all things back..MAGIC!!....my CDP reads the disc flawlessly, tracking is excellent, track changing is lightning fast..so..this is my tweaking DIY audio story..really full of surprises. Next, this CDP will get custom top loading!. The tray system is not working well. But for now..welcome back my old fellow!!

Bad, Bad Hammer, Bad..

I thought this post should be about DIY audio..until a couple days ago I found a smallish (broken) hammer. This hammer was new, bought by a friend because we do not have a small one.

Well this post is going to a BAD Design Case again, or to be exact..bad material selection, bad manufacturing process..bad quality control (doesn't seem it has any)..God know what else..

Ok, here is it..



I'm kind of speechless when I saw this pretty hammer. The material used is bright cast iron instead of a forged one which is a standard in the (good) hammer industry. Also the head is broken right at the most critical area and happen to be less material there. Have you seen a (good designed) hammer bulged around the hole of handle attachment?..Exactly! Here, some more pics.


The label says "Target" Contractor Grade ..Graphite..whoaa!!, what contractor? house of cards for sure ha ha.., another look how the attachment hole looks like, far from smooth, just waiting for a small crack to emerge (this material is kind of brittle) and then...thwak..broken

The only good design here is the color selection, it's pretty & catchy, makes my friend bought it, ..also the wooden handle is stronger than steel ha ha...too bad I didn't saw his expression when it happen. I'm still speechless..do you?

Check your Loudspeaker Crossover

It was last week, when I brought my 'analogue arsenal' to my Dad's home. He want to listen to old vinyls he discovered lately in the house. All set up, all LP's cleaned (washed to be exact), put an LP from Tony Bennett..this great guy voice's sounds great..but why is the right speaker sound more pronounced?..aah..the old Technics left tweeter did not work..why?..

Took the box home and off the grill, ups..the woofer dust cap did not look right, off then with the tweeter, the mid (it is a 3 ways system) and the crossover. Checked the tweeter with a multimeter, yup..it's dead all right. Those cheapo crossover !, they use a very cheap bipolar electrolytic capacitor (small cylindrical thing). They have a limited life, and when it did went bad even the speaker protector can not do anything. There goes the culprit, and I have replaced it with two quality film capacitors, now you'll have extra 10-15 years of listening pleasures.

So, please check your 'expensive' JBL's, Bose's, Sony's, Phillipses, etc. If you see this kind of capacitor, replace them immediately with film type, the same value of uF and same or higher Voltage of course. Do this before your tweeter goes in to smoke, and if you planned to go the DIY way make sure the warranty time is out.

When I took off many parts of the speaker (it's an old Japan design), I have noticed that I have to use 2 types of screw drivers, found many types of screws, each different in size and form..what??..

In term of mechanical design, this is a BAD design practice. Too many parts, too many items, one too many tool, way to many part bins during assembly, storage, purchasing-inventory management..on and on..(you get the drift..).

I have counted 6 types, plus another 2 on the crossover assembly, oh yeah, another one on the speaker protection PCB in total : 9 types of screws. This is too expensive. Is Technics still around this day?

Thanks for reading

Pentium Motherboard Case

Okay..this one is about PC Motherboard. I have one just like this one on the left at home.

What is wrong with this one? Well, not much will go wrong in, say 2 years. Ok. let's see. The white fins is the heatsink of the CPU, on the right is the DRAM, the brown connector is an AGP graphic card slot.

Note the layout of the CPU heatsink, also the golden one..the direction of air blows through the fins is down towards the AGP slot and up to upper side of the casing, vertically blowing thus. This is important. The heat is better transferred this way (chimney most of the time it is vertical isn't it?).

On the other hand, my third PC, the CPU heatsink has a different layout, the fins are oriented horizontally..that is..the hot air blows directly to the DRAM.
For those who have already tried to touch the DRAM..it is hot already by itself, never mind the additional CPU 'warmth'.
And to make things worst..add some dust..(lot of it after 3-6 months in my case)..and they stick to the DRAM chips, making them more difficult to get rid of the heat, and yes..the DRAM and the slot are also turning brown in color.
Within 3 month I have to replace 1 DRAM, one slot completely shorted & shows burn marks..me? I know better now, which board to choose.

The What's, the Why's and the When's of this blog

Hi friends!

I like to introduce myself here, I'm an aerospace engineer living in Indonesia (a MSc. if you want to know).

The What's :
This blog is all about my passions : design engineering and DIY (do it yourself) - at the moment especially in Audio (yes..I'm an audiophile, a design-geek and of course an avid DIY'er )

The Why's :

First-in design & engineering.

During the course of my education, my first-second-and finally the third employment in local aerospace & automotive industry I have gained a kind of sense of critical design evaluation.

Until to date, as an independent design-engineering consultant, have designed-built & prototyped many products, machinery, custom equipment, big and small, very light to 700tonnes, in the air, on the land and sea, underground..I have always use that sense.

And you know what? I've started to evaluate things that I and my family member uses everyday..a broken toy, tools that keep falling when you put them on table..there must be something wrong. And the answer is yes. There are many products that are poorly designed and manufactured. But there are also things that makes me smile..the good designed products. So there you go "...Good and Bad Design..". You'll find here examples of both..soon.. :-)

Secondly, in DIY- do it yourself

I don't know why (this is not the Norah Jones song.. ) since I was a kid, I like to create things my self. Smashed tin car in pieces & look inside it, modified my first bike-with front telescopic and rear suspension at 12, my go-kart in grade 8, and on..and on..until today.

Why DIY?. It comes out handy & you will know better at the end. I have saved my money most of the time by fixing many non functional things we owned (yes, you'll see them soon). In current tight financial situation, DIY is the way to go.

Why pay someone for the job you can do yourself?, why buy a Denon amplifier costing USD400,- when you can build from kit for less than USD50,- that sounded like an USD2.000,- amp?..well you know now. But very careful, DIY can be expensive..it is in time you spent & money that is. In audio for example, if you search for perfection..before you know, you'll spent USD150 for a pair of capacitor.., don't worry there are much cheaper ways...again..there go my DIY.

The When's :

Why just now I write this? Yesterday I tried to organize my DIY files & photo's..OMG!..there are more that 10 folders of individual "projects"..it's about time to share them with you...hope you'll enjoy & learned (from my humbly mistakes)..

It's in my third years (soon fourth) that I gave lecture on Design at one of local university, also I have documented many products, good & bad designed, thought this might help many people including students. You know, it might even help you when you buy any products..look close, compare, try..imagine..whats will going wrong if you are using them... Me? I don't want spent my hard earned money for things that will regret me sooner than later..so, now is the time. (My God..there are even a broken things they sell next to competitor product!.)