TC Replacement PSUs Being Discontinued

[cpsmusic]

Hi All,

My TC M300 recently decided to stop working. Looks like it's the PSU that's the problem so rather than troubleshoot it I opted to get a new PSU from Fixtronics. Dave from Fixtronics mentioned to me the following that people here might be interested in:

Unfortunately, these power supplies have been delisted and are now deemed to be end of life by TC parent Music Tribe.
This means that when our current stock depletes we will not be able to get any more.

So, just in case you know anyone else who might need one it's worth knowing this as it has come as a surprise to us given that there are still so many TC products in daily use on the planet that use these power supplies.

I imagine these units could be run off a different PSU although the cases are pretty small so I'm not sure a transformer would fit.

Anyway,

Cheers,

Chris

 

[guy_4]

Hello cpsmusic,

Thanks for your post and information.
Until now, I have never encountered a TC 3000 with a dead PS.
Hopefully it can be only a few caps to replace in it.
Like often on SMPS...

Best,
Guy

 

[Khron]

It's been a good few years since, but if memory serves, a bunch of years ago i had revived a Finalizer by just replacing the little "start-up cap" on the primary side of the PSU. Possibly the secondary as well, but it was over a decade ago

 

[mkiijam]

Those have a SMPS for sure, with the standard start up cap issue, and maybe even main filter (the big boy that holds 450-ish Vdc). But, there is also a little daughter card that gets bad caps and a driver IC.

 

[Whoops]

I imagine these units could be run off a different PSU although the cases are pretty small so I'm not sure a transformer would fit.

The Swicthing PSU's in TC Electronics Effects 1 rack units are pretty bad and fail often.

Another PSU could always be used for sure but if it doesn't fit inside you have to use the replacement PSU externally inside a box, no big deal

 

[nickmo]

Hi All new here but

Here to revive a fix for these units.

I have a M3000 with a dead power supply.
Tried all the usual suspects but I'm just throwing parts at it with my limited knowledge of SMPS.
So I've ordered a SMPS 5v +/- 15v that will fit in the Wizard area. I'll deal with the IEC and switch. When I get the unit. Hopefully it will squeeze in there too.
XP Power Switching Power Supply, 5 V dc, ±15 V dc, 1.5 A, 6 A, 500 mA, 40W, Triple Output 120 → 370 V dc from RS components.

the 15v and ground are easy

So now I need to deal with the Standby setup and a bypass work around.
There are 3 wires dealing with the 5 volt/standby section.

Red Wire - +5V - (5V Supply)
Brown Wire - +5VSB
Purple Wire - SB VCC
From my reading of the service manual the standby is powered by a 5v send and then turns on the SMPS with a return signal.
So where should I send the 5 v to?

The main board has

Black Wire - DGND - (Ground)
Red Wire - +5V - (5V Supply)
Brown Wire - +5VSB
Purple Wire - SB VCC-
Yellow Wire -15V
Blue Wire - AGND
Orange Wire - +15V

​

 

[Khron]

I'm quite sure the original power supply provides (or provided the 5v standby), and if it's anything like computer power supplies, pulling the "power on" signal to ground tells it to start the beefier main supply.

Conversely, if there's no voltage on the "on" signal of the power supply, then that needs to get pulled up to 3-5v.

You'll need to get a better understanding of what you're reading in that service manual (ie. the mainboard is NOT the one providing/creating the 5vsb, it is only receiving it from the power supply).

 

[nickmo]

Thanks
Yes I understand the main board has no power.
I'm thinking if I tie
Red Wire - +5V - (5V Supply)
Brown Wire - +5VSB
together. The unit should power on and the Purple Wire - SB VCC is redundant as it's just a return for the old SMPS to switch on
I just don't want to blow it's brains out. Do you see issues with this?

I should add the SMPS that I've ordered has no remote start for the main.

 

[Khron]

Well, i guess that should work, as long as you consider that the unit will then be fully powered up all the time.

 

[ccaudle]

Don't tie main 5V and standby 5V together unless the power supply datasheet says you can do that. All the power supplies I have worked with treated standby and main power as separate supplies, and if you wanted the same circuitry to pull power from main when possible you had to diode isolate the connections.

 

[nickmo]

The new SMPS does not have the standby. The mother board requires it.

 

[ccaudle]

The new SMPS does not have the standby. The mother board requires it.

My mistake, I originally read your description of power supply and motherboard backwards.

 

[pvision]

Some of the TC units have a "real" power switch, some a soft switch, so there is probably more than one style of power supply. They will all fail at some point - I've saved a few just by shotgunning new caps

Broken units are worth saving as the rack ears, knobs & etc are all fallible and I imagine those parts will be NLA soon, if they are not already

 

[nickmo]

Okay...
It all works
Used the RS components SMPS.
Fits into the old wizard supply case with a bit of work. IEC and rear switch fit.
I needed to remove one cage nut and reroute the output wiring.
Screws even line up.

The Purple Wire - SB VCC- is now redundant. As is the standby front panel switch
The New SMPS has 2 X 5v feeds so connect both the
Red Wire - +5V - (5V Supply)
Brown Wire - +5VSB
to them.

All I needed to do was adjust the new PS to get 15.09v +/-.
Powers up and all functions fine.
I'll post some pictures.

 

[nickmo]

he we go
Fitted

Power Supply Switch Mode +5/+15/-15V 40W​

RS Stock No.122-7075Mfr. Part No.ECM40UT33

Old supply TC Part number 720060011

 

[alauth]

Hey @nickmo, would you mind re-posting the picture of your power supply fitted ? And maybe explain your process and wiring a bit ? My good old M3000 has a failing power supply (it takes literaly half a day for it to power on...) and I'd like to save it !

Thanks

 

[OmskInfo]

Okay...
It all works
Used the RS components SMPS.
Fits into the old wizard supply case with a bit of work. IEC and rear switch fit.
I needed to remove one cage nut and reroute the output wiring.
Screws even line up.

The Purple Wire - SB VCC- is now redundant. As is the standby front panel switch
The New SMPS has 2 X 5v feeds so connect both the
Red Wire - +5V - (5V Supply)
Brown Wire - +5VSB
to them.

All I needed to do was adjust the new PS to get 15.09v +/-.
Powers up and all functions fine.
I'll post some pictures.

Hi @nickmo,

I just tried doing this with my Finalizer, and while I did manage to get the same SMPS worked into the case as you described and connected all the wires as you described (aside from the purple SB-VCC wire which you said is now redundant), my Finalizer still doesn't turn on.

What I found interesting is that, with the Finalizer not connected to the new SMPS, I measure the correct voltages on the output pins (2 pins with +5VDC, 1 pin with -15VDC, and the last with +15VDC).

However, when I connect the SMPS to the main board following your wiring (which is also reflected by the silkscreen on the mainboard where the wires connect), now I don't measure the correct voltages from the SMPS anymore. The 5VDC outputs only measure 0.05VDC, and the +/-15VDC outs only measure about +/-5VDC. It's as if there's something on the main board pulling those voltages down.

Have you (or anyone else here) ever heard of this issue? Any ideas of how the main board can be pulling this otherwise-normal voltages down? There's no smoking or overheating parts (though I don't want to leave the power on for long in this state as it could just make things worse)...

Thanks for any insights.

 

[Whoops]

It's as if there's something on the main board pulling those voltages down.

It seems so.

Maybe there's some bad Lytic capacitors on the main board.
Replacing all the Lytic caps would be a good idea, but probably it's not an easy task as probably they're SMD.
At least to me personally working with SMD is not easy