Transcension DC-4P

[TaciturnFriend]

I'm working with a venue that uses one of these, just to control a set of basic lamps, no sound-to-light control or anything like that.

It looks like this:
https://www.djkit.com/transcension/transcension-dc-4p-bulgin-controller.html

Manual is this one:
https://www.manualslib.com/manual/912931/Transcension-Dc-4p.html

I'm getting odd behaviour. I think when it's in "Hold dimmer" mode the lighting should just be controlled by the dimmers and the master dimmer, no programming influence.

But I'm getting flickering - across all lamps, so presumably not a bulb issue - and channels not corresponding to lamps properly. I put a little video of testing it here:

but in essence, the channel flash buttons seem to work correctly, (albeit with some flicker) and the "full on button" does put them all full on, but the individual channels don't correspond to the lamps (eg channel 4 brings up all lamps at different levels).

My colleague here says the kit was working fine until a couple of days ago.

My main question is, does this suggest something programmed (is that possible?), or is it a hardware problem, and if the latter, is there a way to tell if it's the controller or cables or...?

Thanks for any help!

[timsabre]

Hi, the flickering looks like a hardware problem in the controller - probably a power supply problem, maybe dried up capacitors or something like that. These controllers have mains voltage all over inside them and so are a bit dangerous if you don't know what you are doing - don't go poking unless you are experienced in such things.

Also the bulgin connectors used for output are frowned upon for electrical safety, we all used them back in the day but it's quite easy to get a shock off them as the live terminals are fairly close to the surface.

I would suggest replacing it with a separate 4 ch dimmer pack and a mini controller desk.

[TaciturnFriend]

Thanks Tim, I certainly won't take it apart myself. Sounds like a sensible suggestion to replace it.

[timsabre]

OK I just thought I'd better mention it as some people like to dive in and try and fix stuff.

It would definitely be fixable, but given the dodgy Bulgin-type power outlets, might be better to replace. Nothing seems to exist like that as a current product with the dimmers built into one box - you have to buy a dimmer box and a separate fader controller unit.

[sunray]

35 minutes ago, timsabre said:

OK I just thought I'd better mention it as some people like to dive in and try and fix stuff.

It would definitely be fixable, but given the dodgy Bulgin-type power outlets, might be better to replace. Nothing seems to exist like that as a current product with the dimmers built into one box - you have to buy a dimmer box and a separate fader controller unit.

Off topic:

Back in 70's I used to buy those connectors by the box (something like 48) from Norman rose and made a fortune making cables & breakout boxes for mobile discos, I came across someone using them winter 2022 and cringed. Apart from the exposed live parts I always felt they were too small for a decent cable clamp arrangement and the inner wires would regularly be showing.

[alistermorton]

2 hours ago, timsabre said:

Nothing seems to exist like that as a current product with the dimmers built into one box - you have to buy a dimmer box and a separate fader controller unit.

I have an NJD controller similar to that, but I suspect that too is long discontinued.

Closest I can think of is an alphapack 3.

Edit: It appears there may still be some Showtec units with local dimming - the TED pack?

 

Edited May 8 by alistermorton

[pmiller056]

There are updated versions of the '8 pin Bulgin disco light connector' available which have much better shrouding of the socket pins. The product range now also has cable mounting plugs and sockets with much better cable clamping arrangements. Panel mounting plugs are available to stop the need for plug-plug leads (ugh!). It can be a lot of work to update these connectors, but if you have something old you wish to keep going, it is a sensible change. Unfortunately, there are still a lot of the old connectors in warehouses and in use.

[KevinE]

These are a botex product I think (ie chinese budget), the manual might tell you a way of doing a factory reset for a start in case something's gone wrong in the nvram.

One channel bringing up the others might suggest a neutral has come loose perhaps? There will be 2 neutrals in an 8-way bulgin outlet and that lead will probably use both, one for the left set and one for the right, though I can't tell. The bulgin to IEC breakout cables on these things can be appallingly made at times and dont take to being manhandled. I would inspect all those first before condemning the controller. I'm fairly certain they're recent enough to have the safety-approved bulgin versions fitted from new.  Following on I would examine any wire connections inside the panel particularly those that relied on hand soldering as this is where quality control sometimes lacks eg dry jointed flex ends and poor wire jumper installation, main conductors to and from the bulgin outlets to the PCB etc.

 

The flickering flash buttons is probably poor button contacts, usually cheap tact switches which will improve with use.

 

I have one of these on the shelf somewhere awaiting repair that was given to me so I might be tempted to dig it out for fun!

[sunray]

8 hours ago, pmiller056 said:

There are updated versions of the '8 pin Bulgin disco light connector' available which have much better shrouding of the socket pins. The product range now also has cable mounting plugs and sockets with much better cable clamping arrangements. Panel mounting plugs are available to stop the need for plug-plug leads (ugh!). It can be a lot of work to update these connectors, but if you have something old you wish to keep going, it is a sensible change. Unfortunately, there are still a lot of the old connectors in warehouses and in use.

Personally my only contact with any in the last 10 years or more has been dumping them when I find them lurking in boxes and drawers but I'm glad they were improved.

I seemed to be constantly making up boxes for customers with 2 sockets to create extensions and with 4 for splitters and 2 sockets on a box with either 4 IEC sockets or 4 tails tails for 'T-bars'. And all at a fraction of the price of 'commercial units'.

I kept a decent stock of all the parts and 8 core cable (actually 9 core Y-Y but I don't recall it having that title back then) and made sure I always had at least 2 each of 6m & 10m leads made up.

It seemed most people making up their own leads used trailer cable with the thicker white.

 

When I think back now...

Edited May 8 by sunray

[sunray]

48 minutes ago, KevinE said:

These are a botex product I think (ie chinese budget), the manual might tell you a way of doing a factory reset for a start in case something's gone wrong in the nvram.

One channel bringing up the others might suggest a neutral has come loose perhaps? There will be 2 neutrals in an 8-way bulgin outlet and that lead will probably use both, one for the left set and one for the right, though I can't tell. The bulgin to IEC breakout cables on these things can be appallingly made at times and dont take to being manhandled. I would inspect all those first before condemning the controller. I'm fairly certain they're recent enough to have the safety-approved bulgin versions fitted from new.  Following on I would examine any wire connections inside the panel particularly those that relied on hand soldering as this is where quality control sometimes lacks eg dry jointed flex ends and poor wire jumper installation, main conductors to and from the bulgin outlets to the PCB etc.

 

The flickering flash buttons is probably poor button contacts, usually cheap tact switches which will improve with use.

 

I have one of these on the shelf somewhere awaiting repair that was given to me so I might be tempted to dig it out for fun!

I always wired all 3 pins for neutral, one failed was my first thought But I struggle to work out any combination to give that result, I assume there are no more lights connected?

Edited May 8 by sunray

[xllx]

On 5/8/2024 at 11:45 PM, sunray said:

 

It seemed most people making up their own leads used trailer cable with the thicker white.

 

When I think back now...

Iwas clearing out the dark corners of my workshop a couple of months ago and found a half drum of trailer cable, which I used to use to make up Bulgin cables back in 80s and 90s. I can imagine that drum is at least 25 if not 35 years old!

So I used some of it to repair the loom on my trailer!

[sunray]

9 hours ago, xllx said:

Iwas clearing out the dark corners of my workshop a couple of months ago and found a half drum of trailer cable, which I used to use to make up Bulgin cables back in 80s and 90s. I can imagine that drum is at least 25 if not 35 years old!

So I used some of it to repair the loom on my trailer!

Oh you devil, surely not using trailer cable on a trailer.😀

 

I was always concerned about it for Bulgins, firstly most of it wasn't rated for 240V and secondly I always found it to be bulky or stiff.

Edited May 11 by sunray