| T O P I C R E V I E W |
| chandan.ahluwalia |
Posted - Jun 29 2007 : 10:31:34 AM
I have a music system which i brought in 1997 and 2 years back, i got one of its output channel short-circuit while playing a pioneer sub-woofer with it..
After that it turned off and on again and again repeatedly..
At that time, i took it to an electrician and he replaced the transistors and something even weird happened to it and it stopped showing even the display which used to blink before.
After that i showed it to a good electronic repairer and he was unable to find the fault. Then i showed it to another but still he didn't find the problem.
So now it is lying with me.
So can anyone tell me that what can i do with it, i mean whether repair or reuse its parts and if reuse the parts then what exactly can be made out of it. And if it can be repaired then how?
And what usually gets blown when one of the output channel gets shortcircuited. It has 2 High Output channels and two surround 50PMPO each..
(Edit...Move to Electronics Repair) |
| 15 L A T E S T R E P L I E S (Newest First) |
| max807 |
Posted - Jul 10 2007 : 8:29:59 PM
Some guy earlier said this:
quote:
If the output to amp was shorted out and he just replaced the transistor he didn't fix the problem. In older amps components don't like to go out alone! meaning they usually take other parts of the circuit out with them! One transistor being blown can damage other components (right back to the power supply). When transistor was shorted it caused high currents that should have blown your fuses in the power supply! If the repair person just replaced the fuse and transistor with out checking the rest of the circuits out it probably blew the fuse again because the transistor would have taken out more circuitry then just its self!
which actually sounds similar to the problem with my Tascam. On my Tascam, a transistor has blown and it's likely there are other failed components too. Is it possible for you to trace back through the circuit with a multimeter and 'scope checking for faults? Then if you find something that doesn't work, replace it and see if it works. If it doesn't continue tracing back through the circuit until you find the next failed component and so on. I think that's all you can do. |
| chandan.ahluwalia |
Posted - Jul 10 2007 : 5:24:06 PM
Dude, had i not experimented with it playing my sub then this would never have happened! |
| max807 |
Posted - Jul 09 2007 : 2:38:33 PM
My system is a standard consumer home stereo made in 1977. My speakers were made in 1972. The whole setup is still going strong. Just goes to show they don't make them like they used to.. |
| chandan.ahluwalia |
Posted - Jul 09 2007 : 02:01:27 AM
Ya ya.. i get it.. Just tell me that what can i do with its parts?
Ant good circuit? |
| audioguru |
Posted - Jul 08 2007 : 8:07:20 PM
It is 10 years old and doesn't work. Get a new one. |
| chandan.ahluwalia |
Posted - Jul 08 2007 : 3:02:35 PM
Well, it is 220 RMS.. But it used to give a feeling of a lot of power, even more than my pioneer 12" 450 RMS sub but was missing that low frequency responce and when i connected my sub to the system, it sounded at its peak power without any distortion... The system's speakers are rated at 6 OHMs impedence an sub is 4 OHM and i thing that is the reason why it sounded fine with that.
And i took it to an electronic repairs guy who is an ex-repairer of AIWA service centre..
What he told was " I am unable to arrange the small PCB and according to me, that is the sole problem".
So now please tell me that what can i do with it? |
| CurrentOverflow |
Posted - Jul 08 2007 : 11:44:38 AM
Heres a definition i looked up cause Peak Music Power Output was new to me;
[size=2]Have you ever wondered how that pair of speakers they are selling at the discount store for $10 can put out 120 watts of power? Well, depending on your definition of output power...they can...and it has fooled many people! I know people have told me that their home stereo unit has 2600 watts of power output...even though it is connected to a standard 120-volt power supply that is only allowed to draw 2000 watts before tripping the circuit breakers!
The answer to this issue lies in how they measure the output power of the device. Usually if you look at these huge numbers, you will see the letters "PMPO" underneath. PMPO stands for "Peak Music Power Output" or "Peak Momentary Power Output". Notice the word peak. The vendor of the product calculates PMPO based on the maximum power output of the device under perfect conditions and 100% efficiency. These conditions are impossible to obtain, and no device can sustain the PMPO power for any significant length of time without being ruined. The PMPO power relies on the fact that amplifiers can provide short bursts (basically on the order of milliseconds) of very high power. Over time, these short bursts when averaged with the lower output powers, gives the real value.
The Real Power
Vendors use PMPO power to hide underpowered power supplies and amplifiers. When you see something with a PMPO measurement on it, turn it around and look at the specifications. Often, the input power from the AC mains is 5 or more times LESS than that of the PMPO power. You also may see a more accurate measurement, called RMS (Root Means Square) power and DIN power. These types of measurements average output over time, creating a much more reasonable reading. Don't be fooled by cheap products which appear to put out big power.[/size=3]
http://cbll.net/articles/pmpo (No author Given)
Mike
p.s. thanks for making me aware audioguru |
| audioguru |
Posted - Jul 08 2007 : 09:47:51 AM
1800W PMPO is a phoney power number. I call it Whats.
It might be only 200 real Watts RMS (or less). |
| cyclopsitis |
Posted - Jul 08 2007 : 03:54:38 AM
Your problem was taking it to an electrician to get it fixed! Electrician know line power (as in 120 and above) they deal with large breakers and swtches, sometimes diacs, SCRs, and Triacs but they are by no means electronics repair people!!! I take it the guy you took it to didnt' explain fully what he fixed (if anything). If the output to amp was shorted out and he just replaced the transistor he didn't fix the problem. In older amps components don't like to go out alone! meaning they usually take other parts of the circuit out with them! One transistor being blown can damage other components (right back to the power supply). When transistor was shorted it caused high currents that should have blown your fuses in the power supply! If the repair person just replaced the fuse and transistor with out checking the rest of the circuits out it probably blew the fuse again because the transistor would have taken out more circuitry then just its self!
If you really want to keep you should take it to a well known repair tech someone who really knows what they are doing. If the person you took it to would have checked it out after just replacing the transistor he would have found it to still not be working!
I agree with guru if you want good bass get a decent sub! that is what they are made for. Speaker boxes are only about 5% efficent so with 1800W your only driving your electric bill up with little bonus in preformace. If you want good sound you need to put the money into it. Home theater is designed around home theater no a car. If you wanted a high end amp you could pay 60K (22 years ago my parents bought their house for 10k less then that!). But there are many decent systems out there for much less. Onkyo, Denon, outlaw ect. many to choose from
hope that helps.
K |
| chandan.ahluwalia |
Posted - Jul 06 2007 : 5:29:48 PM
Well leave the repair thing as few months back i hooked up its main speakers with an alpine 2-ch amp and the surrounds with a kenwood car sterio..
Now it almost sound the same as it used to with the main unit of its own.
So tell me that what can i do with that junk box? any good idea?
And it was 1800 Watts PMPO so tell me that what will be the approximate rating of its transformer? And the voltage.
And what other parts in it are useful? |
| chandan.ahluwalia |
Posted - Jul 06 2007 : 5:24:41 PM
Ok.. Well, here the good ones cost a fortune..
Every one likes sony here and individual sub woofers are also manufactured by sony!
All i can do is fix a car sub at home but the problem is powering the amp. |
| audioguru |
Posted - Jul 03 2007 : 11:14:09 AM
Sony and many other manufacturers make small music systems. If you want deep bass then add an amplified sub-woofer.
In my country there are many excellent music systems and some cheap ones. The cheap ones don't sound good. |
| chandan.ahluwalia |
Posted - Jul 03 2007 : 06:06:20 AM
That is why i'm asking that what can i do with it...
I think in your country, good stuff is available or perhaps you like sony shit!!!!
I hate the musicsystems made by sony.. They just produce high frequency bass and nothing else.. |
| audioguru |
Posted - Jul 02 2007 : 3:18:19 PM
Aiwa was Japan's cheapest brand. They went bankrupt so were bought by Sony about 5 years ago.
Their website lists Sony and shows no products, just service information for older products. |
| chandan.ahluwalia |
Posted - Jul 02 2007 : 11:41:12 AM
Main channels have about 850 each.. But its sound was crystal clear.. |
