Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems G68D No audio on digital outputs

Hello everyone!

I am trying to install a G68D to use with a pair of DSP7000, but I am facing some possible problems.

The processor is already using the latest firmware, I used Mconfig to assign everything, I can confirm that the processor is receiving sound from the source because the processor are outputting the sound in the Zone 2 output (both digital and analogues out), cable are also working as they should, the processor are able to turn on and control the speaker and the digital audio cable that doesn't work when connected to the Main L/R digital output works perfectly with the zone 2 digital out.

To further investigate the problem, I removed the digital out board and noticed 3 suspicious details, they are the following:
1. Signs of something melted;
2. Signs of black dust on the top of a resistor;
3. A CapXon capacitor tha doesn't fit the quality of Meridian product's as well what seems to be signs of soldering.

The following images are from the board, if someone know what are the melted component and its specs, please let me know:







Does some one with more experience in electronics believe that this could be the cause of the ZERO sound output from this board?

I tried the analogues out presented in this board, configured in Mconfig a sub, set the DSP7000 to small in order to make it send sound to the sub, but the sub didn't receive any kind of sound from it, not even noise.

I really want to find the problem and fix it believing that even after some many years the combo G68 + DSP7000 can produce a really awesome sound.

All the best,

Jorge

Hi Jorge,

It is quite common when the PSUs fail within G-series, that a number of other cards are taken out. It could have been the case with your unit and a poor repair effected.

The components replaced look to only be within the analogue output section of the card, so there must be a more fundamental issue with the G68.
Usually, the FICL card fails - this will result in no digital output (you may still get on zone 2 as that is effectively a direct 'tape out') - a good indicator of this is if the volume control is 'laggy' when a digital source is selected.

Clean and re-seat all cards and try again. Check the capacitors on the backplane - they'll probably be bulging (or should have been replaced) - there is definitely an 'art' to keeping these units running!

Spare cards may still be available, but will probably cost more than the unit cost 2nd hand...

Good luck - you'll need it!

Cheers,

Steve

As Steve has commented this is most likely from power supply failure. Im not experienced enough to offer advice on repairing or should i say rerepairing that board. Perhaps you can find a local shop that could go over the unit. Also i would check and see what the current PSU looks like to confirm it was replaced.

Hi, Steve and HTaddict.

Unfortunately I don't the previous repairs/problems of the G68.

What is the FICL card?

Was you mentioned, Zone 2 are working fine (both digital and analogue).

When I turn the round volume button on the processor, also was you mentioned, the volume didn't respond very well, some times it doesn't change the volume, sometimes turning clockwise the volumes go down, sometimes go up, but it never changes the volume more than 1 or 2 dB.

I will disassemble the unit and check all the visible details.

Here are 2 images of the unit coverless and a closeup in the PSU, that seems to be the original one.





While I don't find a solution for the G68, I will keep trying to find and update the firmware of the DSP7000, they are working fine, I just need to fix some details in the drivers.

HTaddict, you mentioned about some shop to replace it, unfortunately this kind of service is really hard to find in my country, but I will try to find.

Best Regards,

Jorge

Hi Jorge,

Looks like an early unit as that is the older LPT42 PSU.

Make sure that all the cards have their edges cleaned, that may help as they do oxidize and that causes intermittent contact.

The FICL card is one hidden in the first stack either between the Digital and Analogue output cards or between the analogue output card and the video output card.
You'll have a hidden DSP card in the stack too.
In the middle stack, under the comms card, there will be the other DSP card.

Check the capacitors on the backplane for any ones bulging - they should be replaced as they look original.

You may need to ask MrTechGuy to find out prices for a replacement FICL card and maybe a replacement digital out card (if still available)...

Also, it may be worth keeping an eye out for a donor unit.

Good luck,

Steve

Thanks again, Steve.

I will take the time to disassemble the unit again, clean and inspect all the boards, maybe post some pictures here so others can noticed what my eyes are missing, I hope to find a simple solution to repair it.

About the donor unit, I will keep an eye on it, but as I live outside Europe and USA, it will be hard to find and bring it to my country (maybe I could send it to Italy, 'cos that's an Europe country I usually travel to).

Knowing that I will be using the Zone 2 digital outputs for a while, I would like to know if the Zones outputs also use the apodizing upsampler/filter both for digital and analogue, does someone have info about it?

Also, does the DSP7000 speaker, running the latest firmware using a Bluesounde as the source, uses the apodizing upsampler/filter? The 192kHz support for this speaker is an upgrade done with some hardware changes or it is a software thing, available with the latest firmware (there is no note about it in the Meridian Releases Notes)?

Cheers,

Jorge

1. Signs of something melted; That's a small capacitor, will be the same value as the one next to it, was probably melted by the soldering iron when the capacitor was swapped out.
2. Signs of black dust on the top of a resistor; will be heat related, may be open circuit now.
3. A CapXon capacitor that doesn't fit the quality of Meridian product's as well what seems to be signs of soldering.not sure what that is, it's not on the original board?

The large capacitor was changed by cutting the legs of the old one and soldering the replacement to it, this is where I'd guess the damage was done to the other small capacitor.



In the above, there is a cable running from the USB maintenance port to the display, that shouldn't be there.

It seems the G68D you have has been badly repaired in the past, do you know the history of the unit?

All the best,

Steve

It may be worth getting another G68 and using the one you have for spares / as a donor unit...

Hi, Steve.

Thanks for all the informations provided.

The cable seems to be connecting the RS2323 with the front panel, I don't know why.

Is that a why to check the value of a resistor and capacitors without removing it from the board? I have a fairly decent multimeter that I can use to read some values.

CapXon is the blue capacitor, usually it is used in cheap products, not sure if it is original.

About the past history, I unfortunately don't have this information, I bought the system AS IS and my main interest was the pair of DSP7000. Luckily they are working, all amps are working but some of the 8" woofer shows signs of wear due to storage in a humid place and so I send it to someone that can fix it, they are flexing abnormally and lost the connections to the voice coil due to the paper degrading with humidity.

Do you know if the APODISING FILTER is applied to the Zone 2/3 digital outputs? It is not ideal, but in a last case scenario I can use the G68D with the DSP7000 as is for a while, at the time I just want to use it as a 2.0 system in a living room. I already have a good home theater system with everything new running with Arcam, Lexicon and Revel speakers.

All the best,
Jorge

My understanding of the apodising is that it’s applied at the input.

You won’t get an accurate reading as it’s in circuit and the other components will affect the reading

Hi,

That appears to be the original PSU you should change this. You can look up how to do it on this site. I’ve done it wasn't that difficult. I used the 60 watt version runs cooler.

You still have other issues as others have mentioned. I would remove all cards and inspect everything under magnification and go from there. If the analog board that has been worked on before appears to be the only problem you maybe able to find a local tech that may be able to repair it. Otherwise a donor unit is possible but most of those have blown PSU and could have other card failures.

In this case it doesn't appear the original PSU has failed yet. So maybe, removing all cards and cleaning all contact surfaces may help.

Assuming that analog board is working properly.

Good Luck