alesis hr16 problem

[nochtanseenspecht]

just came in today, i bought it broken, well, the guy sayd he'd don't know what's the matter...
i changed the original back up battery with a fresh one, reset it, but it still acts strange :

if i power it, all (!) the led's light, the display lights, but no characters and no sound...

could it be the voltage ? (adapter gives 7,5 Volt~)
or maybe a previous owner used a wrong adapter ? (not ~)
or is the firmware wiped somehow

i hope someone can help me out....can't wait to bent it

[catweazle]

Be careful the HR16 needs 9Volt AC (alternating current), normal wallwarts had DC output.
With a normal DC supply nothing will happen.
I own a MMT8 (the MIDI sequencer) and it also uses AC power.
You do not blow off the device if you accidently connect a DC voltage,
it only does not work but will not be demaged. Inside there are 78xx and 79xx
voltage regulators and they hold up to 30Volts (ok at 30V they will get very hot).

Be sure you use a AC (~)  power supply   
7.5Volts is to low, use a 9V or 12V power supply.
 
Manual
http://www.alesis.com/downloads/manuals/HR16_HR16B_MMT8_Manual.pdf

Additional info
http://burnkit2600.com/gear/?page_id=72&forum=4&topic=6&page=2

[catweazle]

Thinking about it, check the  voltage regulators
(black square with 3 pins)  labeled  7905  or 79xx
where xx stands for the voltage.
If the displays and leds are working means that the 5Volt power source is working right.
The sound needs a negative voltage (-5 or something around)
so the negative voltage regulator can be demaged maybe  ...

[Circuitbenders]

i've had the same symptoms twice with HR-16's before. On the first occassion someone had connected the ribbon cable leading to the LCD screen board the wrong way round. The second time the big capacitor by the power input was making very quiet fizzing sounds. Just replaced that and it sprang back to life.

Are you getting 7.5v from the power supply when its under load with the machine turned on? If so its definately time to get a new power supply.

[nochtanseenspecht]

thanks people ! so it seems a common problem...
well i try that with the cable, and if that doesn't work, i change the capacitor, i guess you mean the biggest...

adapter is in fact a 12 V ac adapter, but it drops to 7,5 V when the alesis is on...
could be a sign of a broken capacitor perhaps...
i hope it is that, very scared its something with the firmware

anyway, i let you know what happen

[Circuitbenders]

Theres some good information about testing power supplies and possible faults here
http://www.talkingelectronics.com/projects/ThePowerSupply/Page80PowerSupplyP2.html

On an unregulated power supply i think you can always expect some voltage drop under load but 7.5v from a 12v power supply seems a little excessive.

One problem that would produce that kind of voltage drop and is a problem i've seen before with HR-16's is if you use a power supply that can't deliver enough milliamps. I have a vague memory of having an HR-16 a while back that had a very underpowered power supply and might well have displayed the symptoms you describe but i can't remember for sure.

[nochtanseenspecht]

Circuitbenders, you are Great ! 

i changed all the caps near the power inlet, changed the adapter, and it works fine !
reading your last post, i think it could have been the 300mA adapter, but it never hurts to change the 20 jear old
capacitors anyway...small job 

i wanted to clean under the buttons as well, but no signs of wear and tear, this machine is like new 
well, in fact, it is the oldest version, circuitboard A, o.s. 1,04 but who cares...it works !
must have been laying on the shelf for many years..

ever since i've found out that it has been used on one of my favourid albums, Disciples meets Jah Shaka,
commandments of dub chapter 5, i wanted one of those ..and now that i test it, i recognise the sound from
other albums as well.. nice classic machine

now i'm thinking what kind of interface i will install... a patchbay for sure. and maybe a row of knobs...
enough space inside for all kinds of knobs and switches !
i was also thinking to glue a joystick on top... or shal i keep it original and use a break out box...
maybe i start with the breakout box (couse i already have it) and later install the best bends on top.

anyway, thanks a lot circuitbenders and catweazle, it works again !

[nochtanseenspecht]

yeah, it's ready ! finally i took time to finish this machine

[nochtanseenspecht]

and the showpicture

[nochtanseenspecht]

i am very happy with it
i know there's much nicer hr16 around, but still, this interface is just fine for me.

i made a seperate box that fits on top of the hr,
there are 5 low value pots, wich each can control 2 bents of choice (middle position is unbent sound)
further there are 2 joystick ports, one is fixed, the other patchable

i realy like the joystick control over sound, it nice to play them rhythmic
i realy like the sounds too, i guess most people here know the sounds

[nochtanseenspecht]

btw, this morning i interconnected the hr with some other bent gear 
but to be honest, not a very big succes so far. well it was fun of course, but not in a musical way.
i found that the hr16 is a rather dominant machine, chipwise
it coult for example trigger fm parameters of my pss390, but it was more like one way traffic...
but, there's some more machines laying around, so who knows what will happen 

[Gordonjcp]

Regarding the power supply problem, 9V AC is a must - less won't really work, more will work within reason - but you will need at least 700mA.  I use a 9V 1A AC power supply originally for a USR Sportster modem.  It doesn't even get warm.

[computer at sea]

A patchable joystick!  There's an idea that makes all the mental gates open at once.  Nice one.