Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems How to change a fuse - HD621

Just received an immaculate HD621 but alas, no power. Before going through the pain of having to send it back I figured I 'd double check the fuse but can't see a way of getting to it and there's nothing in the manual. Looks like I should be able to get a screwdriver under the flap and flick the plastic housing out but its fairly secure and don't want to risk damaging it if that's not the way! Anyone changed one before!?



Thanks,
Simon

You should be able to slip a small flat blade screwdriver in that raised bit (closer to the switch) and lever the cover off.

Brian

I’d disagree slightly try the screwdriver blade under the wee bit that goes up the the edge of the IEC socket and it might need reasonable force

Thanks both - Richard wins ! It even comes with a spare tucked away. Unfortunately the result is still the same - dead (and nothing to suggest the fuses are to blame - presumably there would be a split in the wire inside the glass had one blown but they are fully in tack).

Rats

What I am about to say may be nonsense because I sold my HD621 a few months ago and I forget things, but when I took it out of storage after 5 (warm, dry) years I needed to check it prior to sale. I seem to remember that I thought it was dead. It wasn’t. I had configured it when last used (don’t ask why - can’t remember) in a way that hid all inputs so there were no lights visible. I had to configure it to defaults using mconfig and RS232 to revive it. As I say, perhaps nonsense but just check via RS232 that it really is dead.

Thanks, tried RS232 but just says no product detected. Its frustrating as it's in perfect condition.

Hi. I suppose you have already changed the fuse in the main power plug or tried a different power lead. Just a thought

Open the case and check the power supply. They are very similar to what is in the G series and have an adjustment pot. I have had units acting squirrely work fine after an adjustment.

Wow, left it alone for 20 mins and its suddenly come on all on its own and is working fine! Maybe needed time to warm up - it was a long trip!

Well done! When things don't work, provided there is no obvious burning or fizzing etc. what you did is very sensible. Electrolytic capacitors are chemical products and under voltage they can re-form to some extent. This may have happened (in the power supply probably) bringing things back to life.

Simon,

I’m afraid your power supply is failing. The fact that your HD621 came back to life 20 minutes after being switched on tells me that. This is exactly the same symptom I had on my own HD621 six months ago – shortly afterwards it failed completely. Whilst yours appears to be working ok now, it too will fail completely soon. Don’t wait for this to happen as it could damage other parts of your HD621.

I doubt that any electrolytic capacitors have been “reformed” – but you can do a simple check if you like. Turn your HD621 off at the mains, wait for an hour then switch it back on again. If it jumps back to life immediately then perhaps they have. But if it doesn’t come back on immediately this confirms that the PS is failing.

The good news is it's very easy to replace the PS. If you’re comfortable lifting the lid yourself it is a simple component swap. The only special tools you will need are a Torx screwdriver (T10 from memory) and an electrical multi-meter. Both are readily available for modest prices if you don’t already have them.

Just unplug your HD621 from the mains (that’s important!), remove the Torx screws to get the cover off, unscrew the power supply cage and the earth lead, unplug the old power supply and drop the new one in its place. Then put everything back together again the same way you took it apart. Incidentally, the voltages come pre-set although the 5V setting is adjustable and it would be good practice to check this.

If you’re not comfortable repairing it yourself, Mr TechGuy should be able to do it at a cost effective price.

BTW, I just did a quick check on-line; the correct PS - ECM40UT31 - is available from uk.farnell.com for £42.34 delivered or from uk.rs-online.com for £44.06 delivered.

Good luck whichever route you choose and if you need more help then just PM me.

Many thanks, I might well be in touch soon! Sounds relatively simply - I draw the line at soldering but doesn't seem to need it. Will try your suggested test tomorrow (want to get at least a few movies watched while its operational!) and if it doesn't come straight back on will go ahead with the PS replacement.

Good to know Mr Tech Guy is still going strong - think my G61R will be paying him a visit soon - 2nd time the unit's volume control has gone now .