Creative Gigaworks S750 - Relay issue?

[Schern]

Hello, I've got a Creative Gigaworks sub that behaves a little oddly and I wondered if anyone could point me in the right direction as to how to resolve the issue. Following the helpful posts on this forum I've already replaced the capacitors in the PSU and brought it back to life from the flickering power light and refusal to switch on. However now I'm trying to figure out what causes it to trip out when I turn it on after a period of time spent in standby.

The symptoms are that when I first press the power button on the separate volume control the power light changes from red to green for an instant before a plink kind of noises comes from the sub unit (which I assume is a relay switching or something tripping and resetting) and it goes back to red. If I then press the power button again it seems to power up normally and works absolutely fine but due to the relay/trip going it has forgotten my volume settings and I have to reset my levels. It seems to do this each time it's turned back on after a period left on standby.

Does anyone have any ideas as to what could be causing it and what I should do to try and fix the issue. It has been doing it since being fairly new but given my recent success with replacing the capacitors and bringing it back to life I'd like to try and resolve this niggling issue if at all possible! Thanks!

(if it would be of any use I can probably get a video of it doing whatever it's doing when it trips)

[Khron]

Re: Creative Gigaworks S750 - Relay issue?

Some DC-protection kicking in? It would be interesting to get a 'scope probe (or at least a multimeter) on the output...

[RJARRRPCGP]

Re: Creative Gigaworks S750 - Relay issue?

The symptoms are that when I first press the power button on the separate volume control the power light changes from red to green for an instant before a plink kind of noises comes from the sub unit (which I assume is a relay switching or something tripping and resetting) and it goes back to red.

Reminds me of that POS 2005 RCA CRT TV.....

[Schern]

Re: Creative Gigaworks S750 - Relay issue?

Some DC-protection kicking in? It would be interesting to get a 'scope probe (or at least a multimeter) on the output...

I've got a multimeter but not an oscilloscope. So where would I need to measure? The output of the psu into the amplifier?

[Khron]

Re: Creative Gigaworks S750 - Relay issue?

No, the output of the amplifier itself, where it "meets" the speaker that those noises come out of

[lexwalker]

Re: Creative Gigaworks S750 - Relay issue?

Hello, I've got a Creative Gigaworks sub that behaves a little oddly and I wondered if anyone could point me in the right direction as to how to resolve the issue. Following the helpful posts on this forum I've already replaced the capacitors in the PSU and brought it back to life from the flickering power light and refusal to switch on. However now I'm trying to figure out what causes it to trip out when I turn it on after a period of time spent in standby.

The symptoms are that when I first press the power button on the separate volume control the power light changes from red to green for an instant before a plink kind of noises comes from the sub unit (which I assume is a relay switching or something tripping and resetting) and it goes back to red. If I then press the power button again it seems to power up normally and works absolutely fine but due to the relay/trip going it has forgotten my volume settings and I have to reset my levels. It seems to do this each time it's turned back on after a period left on standby.

Does anyone have any ideas as to what could be causing it and what I should do to try and fix the issue. It has been doing it since being fairly new but given my recent success with replacing the capacitors and bringing it back to life I'd like to try and resolve this niggling issue if at all possible! Thanks!

(if it would be of any use I can probably get a video of it doing whatever it's doing when it trips)

Check/replace the DIACs on the power supply board...

[budm]

Re: Creative Gigaworks S750 - Relay issue?

Any details pictures of the boards?

[lexwalker]

Re: Creative Gigaworks S750 - Relay issue?

Any details pictures of the boards?

You can find power supply schematics here: Index of /S750 PSU/Power Supply Schematics. Anyway have fixed quite a few of these speakers already (more coming in soon). Primarily have to get rid of degraded glue first, especially at the standby power supply section (particularly the blobs around the opto-isolator). Besides badcaps (especially those 470uF 200V CrapXons), sometimes there are other component failures as well (e.g. 1N4004 diode, 0R resistor, Su'scon/CrapXon 47uF 25V capacitor, etc). The power supply design isn't too complicated, and pretty easy to fix...

[budm]

Re: Creative Gigaworks S750 - Relay issue?

Thanks, I did not know that Tom has the SCH for this board.

[lexwalker]

Re: Creative Gigaworks S750 - Relay issue?

Thanks, I did not know that Tom has the SCH for this board.

Usually in all my repairs, first and foremost I would replace all electrolytic capacitors (get rid of those CrapXons, many of them are 85C general purpose ones) with better capacitors from Nichicon (HE, PW, PS and/or CS series) and/or Panasonic (e.g. TS-ED, FM, ED and/or EE series). Those 330uF 100V ones on the secondary side I've used Rubycon (ZLH or ZLJ series). All replacements are either low ESR and/or high ripple current handling. For that 0.1uF one very close to the toasty heatsink, can use high temperature ceramic capacitors (either NP0/COG, X8R or X7R) instead of another electrolytic.

[edbog]

Re: Creative Gigaworks S750 - Relay issue?

lexwalker:
I'm beginning to work on a 2 channel 100 watt audio amplifier. Without going into details right now, all of the caps are CapXon but there are two big ones-I assume one for each channel- that I need help with: 6800 Mf, 50v, LP vent 85C. I've checked around but cannot find one that goes as high as 6800 and 50v. With your obvious knowledge, what makes would you suggest to substitute for the CapXon that would be available here in the United States. Lastly, what does LP vent mean before the temperature?