Re: Yamaha EMX 2000 Powered Mixer issue
Hi
I Made a contraption i read about on internet from someone else troubleshooting a mixer.Basically you inject a sine wave ( from phone or something else) and use a multimeter probe with one end grounded and capacitor added and the other end to poke around. The probes are connected to an amplifier with speakers. That way you can trace and hear where the signal gets "lost"
I thought at first it could have been the input section but thats fine, get sound on both channels.
I narrowed it down to...
Phlox321
Member
Last Activity: 10-22-2022, 02:10 PM
Joined: 01-09-2014
Location: cape town
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Yamaha EMX 2000 Powered Mixer issue
Hi All
I have a yamaha emx 2000 powered mixer im trying to repeair.
the problem is that theres no sound output on the right channel. Left channel works fine.
Right channel has output when using the phono(headphone output) but not when going through the amplifier
the left peak meters work but not the right
the clipping light however does come on when gain is turned up same as left channel
What i have done so far is make sure that the supply voltages are fine, which they are
I found several cracked solder joints on the amplifier board which... -
Samsung plasma tv PS43D450A2 pixel issues
Hi guys. I have a Samsung plasma Tv with a wierd prpblem.its a samsung plasma PS43D450A2. A little history : I got the tv free from someone as the thought the power supply was bad and was about to throw it away. I check it and found shorted x main board. I found the diodes and igbts were shorted. After a long search for components i aquired them and replaced them. The tv then worked fine for a few months and about 2 weeks ago it started showing random yellow and purple pixels only on about the right of the tv. Its clearly cisible on a white screen but not as noticeable when watching a movie. And... -
Macbook A1181 Not charging
Hey geys, ive got a problem.
My Macbook A1181 is not charging.
The magsafe connector broke , the little pins on the connector itself broke off.
So i found replacement magsafe cables on ebay and bought one, not original i know but its the cheapest.
So i connected the wires to my charger. The laptop now powers on and works fine if charger is plugged in, but its not charging nor are there any lights on magsafe plug on.
I dont know if the macbook maybe got damaged.
Any ideas what to ttest for?
Previously ive used a generic... -
Re: Logik MP-421 LCD Tv Power issues
i replaced the blue cap but same result, it was making that noise before i found the cracked blue cap...Leave a comment:
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Logik MP-421 LCD Tv Power issues
hey guys, i have a logik mp-421 lcd television that wont power on
the tv itself will go to standby when power is applied and the red light will go blue when power on is pressed on the remote but the display self is dead, no backlight and no display on panel even when lit with a flashlight.
ive stripped it and checked capacitor for faulty ones but theyre good, but that ive found was a small blue 1kv capacitor cracked in the middel, replaced it but same problem.
also theres this humming/buzzing/squealing noise on the AC input side right by two transformers.... -
Re: Samsung 920NW 2 Seconds to Black
Thank you all for your help, much appreciated .Leave a comment:
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Re: Samsung 920NW 2 Seconds to Black
Hi all just want to let you know i fixed the screen, yay, as i was stripping the lcd panel toe put in a different ccfl tube that didnt fit anyway and was a tiny bit short, i removed the old original tube which was faulty and as i looked at it, i sal on of the white small wires looked like it been burned or sumthing and upon closer inspection the white wire came loose, so opend it, resoldered and all is well again, oh and the slight humming noise seemed to go away or is just much more quieterLeave a comment:
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Re: Samsung 920NW 2 Seconds to Black
Thank you for the help so far, ill see tommorrow where i can buy ccfl tubes, or maybe salvage from another screen and see what it does thenLeave a comment:
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Re: Samsung 920NW 2 Seconds to Black
What i also have noticed is that when the screen stays on with the test lamp, the backlights flicker a bit and then go steady or normalLeave a comment:
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Re: Samsung 920NW 2 Seconds to Black
And yes the backlight is a bit smaller, came from a 17" square monitor if i recall correctlyLeave a comment:
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Re: Samsung 920NW 2 Seconds to Black
Thank you so far for the helpLeave a comment:
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Re: Samsung 920NW 2 Seconds to Black
I got results from test, i get about 626 on s1-2 and about 628 s3-4, i then connected the original lamps and the one test lamp like suggested, think i found the problem, a failing ccfl , with the one original disconnected and my test connected in its place the screen stays on but has a slight whining noiseLeave a comment:
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Re: Samsung 920NW 2 Seconds to Black
yes i used it just on its own, but will try it like you suggested, my boards the same but what i saw yesterday after checking voltages again, is that one rectifier/mosfet/transistor,cant really remember which is which, number d803, thos three legged ones with heatsink, the one reads 15v as it should according to spec sheet, other one reads 5v-6v and should also read 15v acording to its specs sheet, so looks like i neet to find a replacement?Leave a comment:
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Re: Samsung 920NW 2 Seconds to Black
Ive swopped out one blue cap with another monitors one, no change, and ive tested the 4 sockets each with one test ccfl i have lying around which still works , i have noticed that the bottom socket, the ccfl shines the brightest, then next socket it lights up about halfway, third socketbit lights about three quarters, and last socket lights fully but not as bright as first socketLeave a comment:
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Re: xerox xa-19i
Ignore previous post, looked at wrong resistor in diagram haha, resistor is fine, is supposed to be 0.2ohmLeave a comment:
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Re: Samsung 920NW 2 Seconds to Black
Hi all, ive got the same monitor, same problem, 2seconds to black, recapped whole board, no difference, checked resistors and diodes and almost have same values as in this post, also voltages are okay, but ive found two of those little blue caps at inverter side which doesnt show any ohm value no matter on what setting dmm is, and also the two inner ccfls only light halfway then diesLeave a comment:
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Re: xerox xa-19i
I have another question , i recently got another monitor, a samsung 920nw, same 2second to black, but its been recapped and no difference , bu i suspect it being a blown resistor, i get about 0.2 ohms on multineter but the repair manual diagram states its a 68k resistor, color code is red black silver goldLeave a comment:
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Re: xerox xa-19i
Hi all sorry for late reply, town had power failure, no power for about day and half, but i recapped the 50v and 25 v caps with known good ones and same problem, the mosfets p/n : u1 : D444 be5d3r and u2 : D444 be5e22Leave a comment:
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Re: xerox xa-19i
Hey guys, so this afternoon i had another look at the board, and remembr that those three 50 v 10 uf caps and the 2 25v 100uf caps at the inverter i never replaced with new ones but from ones from another board which is exaclty the same board, if got two of them with same problem, but anyway, i swopped them all out with ones i could find in old ups's and pc power supplies, didnt know if theyre good but i did it anyway, and switched on the monitor, ccfls go on for about 3 seconds then off then they went on again a,d stayed on much much longer, then i switched off...Leave a comment:
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