SL661J PSU tripping

[Resident]

Hi Everyone,

I'm really hoping someone can help.

We are running an SSL 6032 G+ console on an SL661J PSU and have had recurring issues with the PSU that’s never been resolved of thermal cut-outs. The SSL was installed in Nov 2014 and it cut out that very same day, and has been regularly tripping ever since.

The PSU switches itself off in warmer conditions, however temperatures in the machine room where it’s located do not exceed normal operating tolerances for the PSU. It stays off for around ten minutes, whereupon it will start up again. It’s fitted with fully functioning fans which we’re reliably informed by two separate parties are the most suitable for the unit so in terms of the in-built cooling system for the PSU there is no fault. It was fully inspected and cleaned just three months ago.

We have liaised with 3 separate SSL servicing specialists who are unable to explain what the issue could be. None of these parties claim to know much about this particular PSU model though. Although it’s quite widely known about and used, the support documentation appears to be as good as non-existent. So we’re turning here for some help.

Has anyone had similar issues? How (if at all) were they resolved? Who might we turn to for support in fixing this? Is there any way the thermal cut out can be adjusted?

We are understandably very reluctant to spend thousands on a new PSU when we're continually told they're built like tanks and don't go wrong.

Any advice appreciated!

Bruno
Resident Studios

[Dan Korneff]

I had a similar issue years ago with my psu. It turned out to be a faulty thermistor. 
Have you rebuit this supply yet? Might be time.

[Matt Sartori]

If I am not mistaken this is the Japanese version of the PSU.
I don't have a diagram myself but I think one forum member here knows the PSU fairly well.

Alternatively have you been in touch with Graeme Johns? he is the guy who has re-built all Funky PSUs.
Let me know and can put you in touch.

Matt.

[Resident]

Thanks for the quick replies.

It is indeed the Japanese PSU, and it does sound like a faulty thermistor, or at least one that's calibrated incorrectly. It's just seems to kick in the cutout relay at a lower temp than is needed.

You can see why I don't want to buy another when it could just be a trim pot needs adjusting! The console and PSU we completely refurbished and only installed (by a well known UK SSL dealer) 18 months ago, so I would hope it doesn't need a rebuild. It has been serviced three times since then by Peter Higgs. All in great shape - apart from this thermal tripping.

I be grateful for any forum member that that might have knowledge of this, or point us in the right direction.

Bruno

[Matt Sartori]

Hi Bruno,

I know who the dealer is, I have been seeing these PSU going around and I know it was not cheap either
I doubt it would need a re-built there are fairly recent compared to the original and very very solid.

I know Pete very well great tech and neighbour of mine.
Graeme is the guy you want to speak to.

my 2 cents.

Matt Sartori. 

[Resident]

Hi Matt,

I've just PM'd you.

I'd forgotten just how friendly this forum is - thank you again for all your help. I'll report back once we've spoken to Graeme with the findings as this may help others in future.

Bruno

[Resident]

Hi Matt/everyone,

The months have gone by and we're still no closer to solving the problem of this tripping 661J PSU. We've been in touch with Graeme, and he's ready to look at our PSU, but we have not had any luck trying to find a temporary replacement unit so we can carry on working.

We're a busy studio and it would just be uneconomical to shut down for a week or two whilst the PSU is away. So, I'm reaching out to all in the SSL family if you have (or know anyone who has) a PSU that we can rent for a week or two whilst Graeme looks at ours? We're running a simple 6032 G+, so it doesn't need anything fancy, just a standard single PSU.

We'd also be hugely grateful if anyone has any schematics for the 661J, it is so rare that very few have even seen one let alone worked on it.

Thank you in advance!

Bruno,
Resident Studios

[Matt Sartori]

Hi Matt/everyone,

The months have gone by and we're still no closer to solving the problem of this tripping 661J PSU. We've been in touch with Graeme, and he's ready to look at our PSU, but we have not had any luck trying to find a temporary replacement unit so we can carry on working.

We're a busy studio and it would just be uneconomical to shut down for a week or two whilst the PSU is away. So, I'm reaching out to all in the SSL family if you have (or know anyone who has) a PSU that we can rent for a week or two whilst Graeme looks at ours? We're running a simple 6032 G+, so it doesn't need anything fancy, just a standard single PSU.

We'd also be hugely grateful if anyone has any schematics for the 661J, it is so rare that very few have even seen one let alone worked on it.

Thank you in advance!

Bruno,
Resident Studios

My suggestion is to give a call to Mark @ funky

Matt Sartori

[sintech]

Hi, I'm also running the Jap supply (from the same dealer) and it's been perfect! So you defo have a fault.

I have a backup standard UK supply that your welcome to borrow.. it would need setting up for your console.

PM me.

Andy :-)

[Artur D'Assumpção]

I also have on Japanese PSU version on 6000 G+. These were made by SSL japan for their consoles due to higher requirements by the Japan industry.

I don't have the schematics, but I have some documentation on how to set it up and some of the components, but it's all in Japanese. If anyone wants to translate it I can scan.

Cheers,

Artur

[Matt Sartori]

I also have on Japanese PSU version on 6000 G+. These were made by SSL japan for their consoles due to higher requirements by the Japan industry.

I don't have the schematics, but I have some documentation on how to set it up and some of the components, but it's all in Japanese. If anyone wants to translate it I can scan.

Cheers,

Artur

Please do scan it and send it over to me, I have a dear friend who can possibly help

Matt Sartori

[Resident]

That you all so much for your help. Graeme is going to take a look at our PSU today and has managed to source a replacement one from Funky Junk whilst it's on his bench.

Whilst I'm here, can i ask how often you all change the main cooling fans in your 661s? I have sourced replacements from Farnell, which will be fitted to help with airflow as they may degrade over time.

It would be good to hear your thoughts re. continued maintenance of these PSUs.

[waltzingbear]

I've never replaced a fan for any other reason than the bearings were SCREAMING. Very annoying. These are very robust fans that work well even with extremely worn bearings, but always gave good airflow.

Cheers
Alan