Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems G68 power supply failures - Please report

Hello Oleg

Wiki - Power Supply Replacement

Original caps used are mostly Nichicon FW for the audio boards. And Nichicon PM for the motherboard. For the motherboard they are Jamicon. I used Nichicon PM there.

To replace the caps on the motherboard you have to take the whole unit apart, so I also replaced caps on the analogue output board.

The replacement power supply if smaller, so the standard mounting will not fit. I fitted mine using a original mounting point, and on the other side I fitted small adhesive rubber mounts (I think this was from a PC motherboard).

I took pictures of all the boards before changing. I will sent them to Ian so he can put them on Meridian-audio.info

G68ADV Ser.No 100032 Radio ceased to work. Case was hot. Turned off and unplugged. Left to cool down - didnt restart.
No fuses blown, no output from PSU. Top of one electrolytic on the main board near the voltage reg popped.

If you haven't already done so, read the note about this repair in a Meridian Technical Note TN32 document. It notes there are several caps to replace once this happens.

T

T
Where can I find this document please?

Thank you

I'm guessing with a processor failing, it may work for a time and then switch in and out of standby after a time on? Is that the signs of a psu on its way out?
Based on the above assumption.
If one was to measure the voltage after the unit was off for a time, the voltages would read correctly?
On a G61r, other than replacing the psu, should anything else be changed?

G68ADV

Manufactured: 2004
Date of failure: 11/2018

Unit blew the power supply while I was away on a business trip in November. My wife powered down and I opened up when I returned. Power supply was in bad shape, bulging caps and obvious darkening of the board on the power supply. I could see that several caps on cards and the motherboard were also bulging.

I installed a new power supply, replaced all of the caps on the motherboard and all recommended caps per the Meridian technical note 32 (including the 2 caps on the GOEA card). I adjusted the voltage output to 5.2V. Unit powers up fine, display is good, but no digital output and no relays (clicks) when switching sources or on power up like my other processors.

I replaced the remaining capacitor on the digital output card and the single capacitor on the digital input card. Still no sound. I also removed all of the cards and left in FICL, CD, EF, and GOEA for troubleshooting. No relays and no sound when using the calibration function on the processor.

Any obvious next things to try? I suspect some cards still have an issue, and am thinking the power supply failure did some damage. At this point, all of the capacitors on these cards are new- maybe something else was damaged?

Thanks for any advice.
John

I don't think your G68 has a future. It would appear that at least one or more of your cards are toast.

I had a look at a similar problem for a fellow HH - See link

See advice from Marc Koval. Meridian have no cards left and economical repair of your cards is very unlikely.

Sorry.

Thanks very much Tarik- I suspected so, and it is disappointing, but good to have some closure.

I did many of the same diagnostics, including stripping it down to essential cards to troubleshoot. I could not get any sound either, from digital sources, or the test tones in calibration mode.

The power supply went out while I was away, so it is hard to know the duration of the damaged power supply. The unit would not shut off and my wife pulled the plug after she smelled a strong burning smell. It was probably on for a while and did extensive damage to some cards. The power supply was very badly damaged when I opened the case.

From my own experience, changing all of the caps on the cards could not fix the issues, so perhaps this information will be useful for others.

I would not toss it just yet. Send it in, it may be one of the DSP cards or something more simple.

Worst case if it is not worth fixing is you will be out the cost to ship it here if it is best to scrap.

These things are finicky to troubleshoot. go here, The Repair Shop - Meridian fill out the service form and send with the unit. If it is reasonable to fix and you want to go ahead you can send the pmt form later.

Best

Marc Koval