Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems G91 Replacement Power Supply

Brief update: my replacement 60w supply lasted 2 years almost to the day in my G91. Ordered a replacement from newark.com at $48. While it was out of the cabinet I moved things around so it's no longer being cooked by the cable box - hopefully running cooler will help.

Many thanks again for the original post that helped so much.

Steve.

Put in the new power supply yesterday and set output to 5.2V. All good!

Is it working or not?

If not post me!!!

My unit is working great.

Hi, the power supply in my G91 has just failed again. Symptoms are no lights or sounds from the G91. It is completely dead. Checked the voltages directly at the internal power supply pins. It has has 230V on its input and 0V on all 3 outputs. Only physical signs are a very slightly darker patch on the bottom of the circuit board and a slightly toasty smell coming from the transformer.

I can't remember exactly when I last replaced it, but this time I've just ordered an ECM60UT31 from Farnell to replace the ECM40UT31. As others have noted, it's the same physical size. When you check the derating factors, at 75 deg C it’s down to 30W (50% of 60W) which is the same actual output power as the ECM40UT31 (75% of 40W). Maybe it will be less stressed and survive longer!

It’s also worth noting that the Farnell price, including VAT, is less than I can find on eBay and promises free next day delivery - on New Year’s Day!

Don’t forget (as I did when I ordered 6 of them) that Farnell prices are ex VAT !!!

The ECM60UT31 failed last night while the system was playing music . It happened simultaneously with me turning off a light! I could tell because as I turned the light switch off the music stopped!

Same symptoms as before, no indicators on the G91. Just completely dead.

As the ECM60UT31 is clearly no more reliable than the ECM40UT31, I've saved £5 by going back to the 40W version.

Checking my Farnell account records, I see that the ECM60UT31 only lasted 17 months. So I think I'll have a go at getting it replaced or fixed under warrantee.

Hi Adrian,

Have you ever replaced the capacitors on the PSU board next to the PSU?

You may find that the capacitors are causing more current draw on the PSU, causing it to fail.

If they've not been replaced, I would strongly advise replacing them, otherwise, the new PSU won't last long!
From memory, there are five capacitors.

If you need any assistance with this, please drop me a PM.

Cheers,

Steve

Hi Steve,

No I haven't replaced them - yet! Just had a look. 3 of them have slightly bulgy tops. Pulled one out and it measures at 259uF instead of the 1000uF it says on the tin. So I will replace them. - Ordered from eBay for £2.11 inc p&p.

But I'm not convinced that this has contributed to the failure. There is no sign of overheating on the power supply and it doesn't smell burnt. And it was a bit of a coincidence that it failed at exactly the same moment as I turned the light switch off. Feels more like a transient to me.

Also just checked the 2200uF 25V capacitor - C3. That comes in at 2143uF. So still within tolerance.

Thanks
Adrian

Hi Adrian,

I replace all the capacitors on the PSU board regardless of whenever I service a unit. Unless you've got a problem with one of the cards (which I doubt), replacing the capacitors will give the replacement PSU an easier life...

If their resistance is quite low, that will shorten the life of the PSU.

Hopefully, that will get everything working reliably again.

Cheers,

Steve

Working again now

I replaced the power supply with the 40W version from Farnell and the 1000uF capacitors from eBay. If had had realised they also needed replacing, then I could have ordered them at the same time as the power supply from Farnell. The power supply took 24 hours to arrive, the capacitors a week!

And I remembered to set the power supply output voltage to 5.00v

I've kept the blown supply and hopefully will find time to analyse it and work out which components actually blew. Will post any findings here.

Thanks again everyone for your help

Hi,
I'm sure there was a Tech Note or guide or something that told you, with pictures, how to set the 5V supply for a G91 or G91A by measuring the 5v supply on the main processor board. But now I can't find it.

Does anyone recall the note and know where to find it?

Thanks

Adrian