Fusion 6HD boot up/freezing problem

[jiffy]

My Fusion started to freeze occasionally, and I'd have to power up again to be able to use it.

Recently, I've had a problem with it actually starting up.
I'd turn on, and just get a blue screen with a few of the buttons lit and the hard drive wouldn't spin up, and I'd have to switch off and on a few times before it would start properly.
This problem has got worse over time and it's now got the the stage where it won't boot up at all.

I took it apart, thinking that it could be the hard drive going down, but I connected a PC power lead to it and it span up ok.
I then measured the voltages on the Fusion to the hard drive:-
Without the hard drive connected, the 5V lead read just over 4 volts and the 12V lead gives 10 volts.
Is this within working parameters of a hard drive?

So I'm now thinking it could be the power supply.
Can anybody give me a list of voltages that the Fusion power supply is meant to produce at the connectors on the main board?

I remember on this group a while ago, there was a thread about whether the Fusion would work without a hard drive.
I did a search, but couldn't find it. So, will a Fusion work without a hard drive connected?

Thanks,

Paul

[jiffy]

Even though nobody seems interested in my problem, I'm going to give an update anyway. ;D

It is definitely the power supply.

On removing the supply board and having a look underneath, I could see an area that had been getting very hot, so hot that it had detached the PCB track from the board where two large resistors were soldered.
I set to with the soldering iron and bridged the track and all seemed well until I replaced the control panel/endcaps assembly when it stopped working again!
Anyway, after much faffing around, I discovered that if I flexed the power supply board, the Fusion would boot up ok, but as soon as I released the pressure, it would cut out.
There must still be a dry joint somewhere on the power supply board but I couldn't find it, so my cure was to put some packing on top of one of the pillars that the board is fixed to, thereby permanently flexing the board.

I realise it's not a very elegant solution and that the board could crack if it gets too hot, but it seems to have worked and it's a lot cheaper than a new power supply, so that will do for me!

Paul

[Jamie]

I've just (last night) replaced my power supply. I took apart my 6HD and fitted the new unit I purchased from Alesis.

I'm no expert with electronics, but I presume the old power supply had shorted out; the underneath of the PSU was black and charred, and it had left a 2 inch black scar on the inside of the Fusions under-side case.

Fitting the unit wasn't too bad, there was a moment of utter panic when everything was out and lying in bits on my floor, but in the end it took around 2 hours. Now my Fusion is fine.

Anyway, you sound as if you've fixed yours, so hopefully you won't have to end up getting a new unit.

[jiffy]

Glad to hear that you've got your Fusion going. It can be a bit of a scare with everything in pieces!

I see you live in London and just as a matter of curiosity, how much was a new power supply and how did you go about ordering and how much was it (just in case mine does give up the ghost)?

Did your old supply have what looks like a retro fit diode on the track side of the PCB and does the new one have one?

Paul

[froggy54]

Hey mate,
we're interested in your problem but you gave the solution of the problem in your post.
If you search the forum, you'll see that some of us already had a power supply problem (Jamie and I already posted on this subject) and I think it's definitely a weak part of the fusion.
A hard drive requires 12V and 11,8V would be enough too but 10V is a bit short.
As to the Fusion booting without HDD, it's already been discussed a few times and the answer is yes.
That said, samples loading times from a CF card would be worse than from the HDD but a HDD need more care (no bumps, more power) than a CF card. Don't forget that the Fusion only manage 2 Gb CF cards or less.
Hope it helps !

[Jamie]

Jiffy, the new psb was around £85.00 inc postage, I ordered the part direct from Alesis by calling the uk support number.

You can also order from these guys www.instrumentalparts.com/9-79-0361.html

Re the retro fit diode, I'm sorry I have no idea, I really no nothing about electronics. I could open up my Fusion again and have a look, but unfortunately I've thrown the old part out already, sorry.

Here's a big(ger) picture of the new psb just in case you can see any difference... ep.yimg.com/ca/I/yhst-15436568105612_2091_33756328

[jiffy]

Thanks, chaps.