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Post by Jesse on Jan 11, 2015 0:49:16 GMT
I can not read the output voltage printed on the dimmer PCB to the Inverter PCB do to a white compund covering the Dimmer PCB around the out wires. The next time I have one of the Fusions opened up I will check the voltage on the Dimmer output to see what it is and use the dimmer to see if voltage varies I don't think I did that before
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Post by pablofcid on Jan 11, 2015 23:38:33 GMT
I have read the specifications for the display. In order to control the brightness all you need to do is to setup a pot in series with the power to the backlight. That can limit the current to the LED and hence control the brightness, and is the usual way to control brightness in this type of displays. BTW, I don't see the need to keep the 'old' dimmer board (at least for the display, don''t know if it is used to generate some other voltaje needed elsewhere). A pot in series with the LED backlight is simpler and perfectly valid solution to feed the backlight and control its brightness. If the display backlight is of 5V specifications, I would recommend to get 5V from the diskdrive power connector, insert a resistor and a pot in series with the LED backlight (resistor to set up the maximum current, not to allow excesive brightness/heating and possible damage to the LED backlight; and the pot to be able to control the brightness down as needed). That pot has to be arranged somewhere in the Fusion chassis, but that should be no problem (who cares about ruining the warranty :->). Some displays use 5V led backlight, others use 3.3V. In that case, better get a 3.3 power source from the Fusion instead of 5V, of course.
Regarding the contrast, it is simple to setup and can be checked at the display datasheet. All that is needed is a pot between two pins, with the variable point in the pot feeding a third pin. If you need details I can extend on that.
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Post by parametric on Jan 12, 2015 1:06:30 GMT
That's a nice idea Pablo,
What would be nicer would be if the existing little knob could be made work in the way you describe . . . - so nothing is different to the user . .
I hadn't realised that the knob is NOT actually ON the dimmer board.
Is it on another board - or is it just a chassis mounted pot - WIRED to the dimmer board?
parametric
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Post by Jesse on Jan 12, 2015 2:53:41 GMT
The dimmer is on the right Front PCB in the top left cornner of the following picture link
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Post by pablofcid on Jan 12, 2015 13:27:52 GMT
It seems not to share any connection with the rest of the Fusion directly at the PCB (although I can't see the other side). If it is the cable and connector the only means by which the pot talks with the rest of the Fusion it can be isolated and applied to the new type of contrast control that the new display demands.
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Post by pablofcid on Jan 16, 2015 12:34:06 GMT
Lovely news: I helped a friend to find a suitable display replacement. He has already got his hands dirty and he confirms that both Little PCBs can be removed when mounting the new LED based backlight LCD, and (drum roll, please...): the original contrast knob is still operative for the new display. It is not so strange, as in fact the contrast is only related to the LCD part of the display (the 20 pin connector) and not with the backlight. I suspected it would work once I saw the photo of the contrast knob, which lays isolated from the rest. The cable from the contrast pot goes directly to the relevant pins on the LCD connector for contrast control.
His choice was also for a White display, and it can even be read without backlight on, and he says that it integrates extremely well with the aluminium chassis of Fusion (probably too well integrated for his taste, although that´s something I would really love).
So the installation is very simple, and the only decission to take is to mount or not one new pot for brightness control (I would really recommend to do it, but again that's a matter of taste). At least a provision for an internal pot to have an adjustable level of brightness to taste and not necessarily to maximun is advisable.
cheers!
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Post by Jesse on Feb 26, 2017 16:50:52 GMT
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Post by Jesse on Dec 9, 2017 20:09:14 GMT
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Post by q5353q on Dec 21, 2017 3:52:29 GMT
On the dimmer board, resistor R1 appears to be: RED / YELLOW / BROWN / GOLD 240 Ohms 5%
or
RED / YELLOW / BROWN / BROWN 240 Ohms 1%
Can anyone confirm either of these, or alternatively identify this resistor and its specs. Thanks in advance
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Post by Jesse on Dec 21, 2017 15:15:17 GMT
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Post by 2manykeys on Feb 11, 2018 3:58:03 GMT
Jesse,
My 8HD is on the way from Guitar Center and I've been reading various posts about the PSU and LCD. I ordered the LCD. Thanks for posting that info. How has it worked for you since then? No issues with the backlight?
I was wondering how that 3.4V supply to the inverter worked driving the LED's. There's no way to know what the draw was on the line originally so I wondered if the LED's might pull more current. If it's working for you these last few months I assume it's within the load limits.
Thanks,
Scott
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Post by Jesse on Feb 12, 2018 14:50:41 GMT
Alesis Fusion affectionately known as "The Beast" Scott, if you use the replacement LCD Display with 5 volt LED back light or if you replace the CFL Backlight with a LED Backlight you do not need the Dimmer PCB or the DC-AC Inverter PCB The small connector going to the Dimmer PCB from the RIGHT FRONT PANEL ASSY PCB part 9-79-0308-A provides 3.4 volts DC which is perfect for the 5 volt LED Back light and allows you to control the brightness with the dimmer switch.This also eliminates two heat sources and reduces power drain on the PSU
In general LED's draw less power than other light sources Jesse
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Post by Jesse on Feb 25, 2018 17:43:30 GMT
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Post by Jesse on Feb 28, 2018 14:06:32 GMT
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Post by mstsfreak on Jun 22, 2018 18:50:25 GMT
I saw the LCD display and would like to order one, but it looks like they do not ship to the Netherlands. Can anyone help me?
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