anyone can help me repair my gigaworks t40?

It should be okay.
Just pay attention of size of the capacitor.
Usually it will be either taller (Height) or fatter (Dimension), so pick a same size & high ripple current & long life & genuine one could cost some time.

WOW, is that really so easy? I'm more like a computer software guy rather than a hardware guy, drilling & gluing & wiring means it's hard to me

Usually, I stay with the default 4 (||||_ _ _) volume, and I didn't feel much heat in nowadays (I mean, winter/spring), but I do feel much heat in summer.

I guess music with low frequency may help the air flow across the box, you can feel the air flow at the inverted cube (the big hole on the left side). On the other hand, play low frequency music may cost more power, hence more heat are generated .

Where to send for 110V to 220~240V modification?

You can do it yourself, you just need soldering iron, solder, and basic soldering skills. Just look at the pictures. There is "conversion manual" and the other image is 230V version.


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Hello Every one i join this nice forum to try to fix a cambrige 250d thx where the board seem very similar to yours.


I have an issue with it : i get no sound from speaker or a very very tiny and noisy sound.

the switch on look fine ( i have steady green led and i hear the relay clic from stanby to on)

i check visually the psu board and caps seem to be not bulged.
i removed crappy glue to avoid short on the psu board

but problem is still present.

Can you please help me to debug the circuit i dont know where to look first psu or amp board ?. Can the top234 dead if the led is green ?

i found issue :

small resistor R179 only 1 black band is not conductive at all ( close to the big 680uf 200v ) changed

high esr for C205 47uf 25v give to me 5.6 ohms --> changed

C206 75nf instead of 0.1uf 6% loss --> will be changed i need to found one


many thanks

This post has been edited by drepou: Jun 11 2017, 01:17 AM

I am not a profesional electrical enegineer but in basic i can recommend you to do following steps.

1. Properly visually check all parts for any kind of damage, crack, pop, burn track from explosion.
2. Measure all FET's and diodes with digital multimeter. http://electronicsbeliever.com/how-to-know...t-is-defective/
3. Check all caps for capacitance with multimeter capable to measure capacity. Some of them must be desoldered for correct measurements.
4. Check all PCB traces with multimeter in conductivity beep mode. Even check for broken parts leads as i found here:



5. Schematics will be very helpful.
6. Check inductors and transformer windings for continuity or resistance.

Good luck!

i tested all the diode ok work good, for capacitors i can't test all off them because my tester dont work if i dont disconnect at least on pin to mesure. i dont want to unsolder all caps !

i tested the biggest ones ok and the small who was suspicious in this thread

thanks i get some improvements after replacing fews stuff on psu board :

C205 C206 and the broken 0 ohms beetween the to big primary capacitor.

Now i get sound quite audible ( fews watts ) but not the fully 150 watts for sure !!! both speaker works ( tremble and boomer ) sound is correct but with some low hummm and white noise.

i checked on psu the votalge between big output wire CD+ and CD- (audio board connected ) and i have only 8v is it normal ? i was waiting to get something like 24 volts... i have to investigate in this side.

also checked the 3 LM78XX i get 27v on ( lm7824 ) and 12v 10v on the 2 others ---> i need to read and check the ref to see the normal output voltage for these one

thanks for your help

For the S750 PSU board are the thick conductors -24 and +24V and more than 80 V without load (with load-amp boards connected is around 65V)

Check the markings for voltage regulators (L or LM7XXX) google it for output voltage and measure input voltage and output voltage directly on the input and output pins.

27V for 7824 is a lot, there must be something close to 24V.

8V is very low to power up the amp.

It's was not a good idea to disconnect the CD- and CD+ conductor from psu to audio for checking voltage ! by doing that the sytem is now not working any more even red light stop it after 1 sec ... reconnection of wire but same things .... :-( back to ground zero....

Hmmm, that's weird. In S750 i can connect and disconnet at any time and nothing wrong was happened. Check the diodes again, and power mosfets with diode checking or continuity mode. Does have your circuit TOP243 or similiar? I had one PSU board where was faulty TOP243 and a faulty diode powering it. During this fauilure the PSU board does absolutely nothing, no transformer buzzing, no LED light on, no nothing. After replacing diode and TOP243 everything was working like new even with old capacitors.

yes i have a TOP243Y i was thinking it was working because before the led was green and relay was working but not now.
I will order a new one but i just want dont miss something else and burn the new one.

Nice advice MichalD i checked today D9 close from the top243 now she is shorted !! i get 0v when reading backward... she was ok before.

i also noted some Strange behaviour on the 4 diode who are close from CD+ CD- some of they give me strange value connected... like 0,2 on conductive way and 0 for other diode reverse way... Strange i will unsolder to confirm





I also noted i thinks issue with Q17 Q18 Q35 Q34 i get the 0,6 on one direction but also when i reverse the multimeter pins...







This post has been edited by drepou: Jun 16 2017, 03:56 AM

Chek this PSU scheme for S750 if the TOP243Y part is the same in your PSU and check parts around your TOP243Y specially diodes and find your diode "D9" by following the PCB traces and check it.


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diodes checked in fact seem to be correct if checked unsoldered... now i have to unsolder the transistor to check it it's a real pain to be oblige to desolder to check !

This post has been edited by drepou: Jun 18 2017, 12:51 AM

hello again i changed the top243 but issue is the same i have only 8,8V on CD+ CD- even if i disconnect the wires going to audio board.

( i disconnected only the CD+ and CD- wire )

power on work, led is green, i get huge noise ( kind of hum on satellite speaker ).

I dont know what to do now without schematic is not easy

other note there is 2 100ohms resitors connected to CD+ it's seem that the other side of the resitor is grounded ?? ( bip with the black wire connected to the big aluminium rad where is screwed the psu board. ) is is normal ? if it's the case with 80v it will be a waste of 800ma in this resitor so p=UxI --> 64 watts bye bye the resistor or this is not the groud....

or it's mean what the big rad is not grounded and is used to send power ???

This post has been edited by drepou: Jul 15 2017, 10:13 PM

Hi,

I have replaced all the caps on the power board, the light is now steady no flashing and it worked for one evening. This morning I cam down and the sat speakers front are just crackling and quiet, the Sub is humming and no real sound is coming out of it.

By any chance do you know this fault, the Sub light is steady so it is not the same fault again. could this be something stupid like the bass speaker cables come off when I pulled the boards out. I suppose that I could just look, but maybe you know this fault and can help.

regards and thanks in advance
smudge

Hi guys, I own a Gigaworks S750 speakers set too. Despite trying so many times I'm not able to get hold of Lex. Does anyone here knows where I can get this fixed? I have no idea what is the actual problem. Probably same as others experienced here. I have never opened it before to check the components. Please do message me if you know someone who is knowledgeable to fix it

Hello, i wasn't here long time because of lot of work and huge fixing for all my other sets of S750. Now i am finishing preparing for much improved heatsink for PSU boards.

Without the schematics it is very hard to find the problem.

For the resistors i don't know if it is normal.

In S750 PSU is grounded only heatsink cooling mosfets. But there is no electrical conductive connection between mosfets and heatsink. The other heatsink for diodes and V.REGs is connected to positive 70V rails thru two capacitors each rail and common inductor. There is no other connection to heatsink so i don't know the purpose of this connection. The other heatsink is connected to positive wave of grid powerline after diode bridge and one D9 if i am right. And now i remember i've touched it with bare hand during operation to check the temperature





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Check the area around the big 1000uF capacitor, small yellow one and SMDs around on both AMP boards. Look for the burned or cracked components. Do you removed all degraded glue from the PSU, AMPs and audio processing boards?

Help Me!
https://www.youtube.com/watch?v=4tFY61IPh-w