Jem Technohaze

[Happy Jack]

Hi,

 

We recently picked up a Technohaze without a remote that was destined for the skip. We weren't given any details regarding it's condition, only that it was 'completely fuct'. I've pulled a few old threads on here that describe various problems - mostly concerning the sensor - but none that seem to be troubling us. I'll explain.

 

Although 240v in, the unit fails to reach working temperature and so does not illuminate the green ready LED. Probing the heating block, it only seems to be receiving 33.4v from the PCB which explains why. The pump is only receiving 23.1v from the board as well, so it's looking a little sorry right now.

 

Would be very grateful for any advice. Does Gary still frequent the board?

[the kid]

I had a technohaze I scrapped a year or so ago. It sounds a lot like what I had wrong and the whole thing stemmed from a clogged heating block and the fact the board/s were filthy. There was also a issue with the fluid sensor so without the sensor understanding there was fluid it wouldn't heat up.

[Happy Jack]

I had a technohaze I scrapped a year or so ago. It sounds a lot like what I had wrong and the whole thing stemmed from a clogged heating block and the fact the board/s were filthy. There was also a issue with the fluid sensor so without the sensor understanding there was fluid it wouldn't heat up.

Thanks for your reply.

 

While cosmetically the unit looks a state, the boards / internals are relatively clean. The sensor, too, works like a charm and reads the expected 2.2v / 2.5v with the corresponding LED. At board level I'm at a loss.

 

I'm still waiting for Jem to get back to me, but I imagine it is salvageable.

[KevinE]

If it's anything like the Technofog, it wont attempt to heat unless the remote is plugged in. This is becausre the remote can control both the heater on/off and the pump off/slow/fast.

[Happy Jack]

If it's anything like the Technofog, it wont attempt to heat unless the remote is plugged in. This is because the remote can control both the heater on/off and the pump off/slow/fast.

I was sure one was able to bypass the nuisance of not having a remote via the board. Going by an old thread, the remote is simple a push switch on the 15v in, and a pot on the 10v voltage from the series divider? I hope the fix is a simple as that, so we'll give it a try and stop speculating about parts. Thanks Kevin, PM sent.

[KevinE]

Going from memory (I'll know more tomorrow if I get any free time in the workshop!) the remote gives out something like 1.8V to tell the heater to switch on then 2-10V to tell the pump to run, so obviously if the remote's not plugged in the heater wont even attempt to power-on as the control input pin will be at 0V. The remote socket gives out (something like) 15V which is used by the remote to generate the appropriate voltages; it's not meant to be linked straight back into the control input. There are also 2 LED drive outputs for 'heat' and 'ready' which operate independently...since the machine will switch the heater on and off with proportional control even though it can indicate a constant 'ready' if it's hot enough to work.

[godoflight]

I believe the remote actualy outputs a PWM type signal (i.e. pulses), it is certainly more than just a button and a pot (unlike some old Jem smoke machines).

If you short the pins then assuming the 15V supplied isn't to much for the receiveing circuit you will have a smoke machine rather than a haze machine.

 

You can check the heater out by removing the heater connections from the PCB and measuring their resistance, I can't remember what it should be from memory but a bit of ohms law will tell you if it's about right. For test only you can then connect the heater directly to the mains and once it is hot give the pipe from the pump to the block a squeze to push some fluid in and you will soon find out if its blocked or not.

Don't push fluid through when it is cold or you may short the heater supply to ground and perform an unexpected test on a nearby RCD (the thermal cutout is right by the outlet).

 

The pump is never powered at 100%. It is usualy just given very short half wave pulses, you wont pick it up on a multimenter. Just listening for its clicks is easiest, when you have a suitable remote control of course.

 

I have had technohazes before that have got old and haze seeps around the sides to the PCB and connectors causing usualy one of two things to happen, either nothing comes out or its on 100% regardless of the remote setting!. Eventualy they get to the point that no amount of cleaning fluid up stops it, I suspect the block is actualy leaking somewhere.

[Happy Jack]

A thank you to all for your collective input. A special thanks to Kevin and Gary from Jem who got in touch and enlightened us. I'll update the thread as we go along.

[Neil Hampson]

From my own experience of older TechnoHaze/TechnoFog machines, a simple remote works fine, some units have a 3 pin XLR, others still have a 5pin DIN plug. with the 3 pin XLR, the pins are simply +15V power, 0V common and a 0-10V output, itf there is nore than about 1.5v on the input pin the heater block should start to warm, no voltage, no heater. at it's simplest the 'controller' is just a 1K pot across the power and input pins, withe the pot travel limited to give a 2-10V output, (therefore a pot and a multimeter would suffice to test your machine). There are much more complex controllers out there including the timer units, I think that you must use the 5 pin DIN connector to get the ready and heating LEDs