Eventide H3000,back on duty,mod for analog bypass ?

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andre tchmil

Well-known member
Joined
Jun 4, 2004
Messages
1,654
Location
land of chicon
Hi all,
I have a blackface H3000 here.
Everything works just fine, except for the large LCD display backligh which is very weak.
I can adjust the brightness with the "Function" parameter, but it's still to dimmed.
Anyone had to repair something like this before ?

thanks
 
Hi Andre,

I've always wondered how to adjust the screen brightness on the H3000 :) any chance you could explain the method for me?

many thanks in advance.
 
Hi Larrchild.
Thanks for the help; but I don't see any cap around the LCD. :?
I Measure around 5V at the backlight.

Yes, I did the ROM reset, etc.
 
They use a small switching supply to generate the backlight voltage.
The cap is part of the oscillator. Look for a small ferrite core transformer. It's near there.

The voltage on the backlight is much higher than 5v.
 
It is Optrex DMC40267-yu-neg display (U1). Back light is connect to pin nr. 15 (ground) and 16 (resistor R23 5R6/1W). This resistor is directly coupled to +5V DC. On pin 15 should be 3.9V/0.2A.
LCD contrast signal is feed from U3 (74HC174) to Optrex pin nr. 3 (VO).
It probably means, you can'n change the backlight, but you can change the contrast of the display. I guess...
 
[quote author="SSLtech"][quote author="andre tchmil"]in function mode, spin the dial wheel.[/quote]
It's actually the contrast, not the brightness, IIRC.

Keith[/quote]

You're correct. It's the contrast adjustment, which is perfectly working on my unit.
 
[quote author="andre tchmil"][quote author="SSLtech"][quote author="andre tchmil"]in function mode, spin the dial wheel.[/quote]
It's actually the contrast, not the brightness, IIRC.

Keith[/quote]

You're correct. It's the contrast adjustment, which is perfectly working on my unit.[/quote]

This function doesn't work on my unit.. I guess it's stuck on full (grey face SE model)
 
Nope.

Sorry... That's quite a big deal. Not least clock-stripping and then clocking the unit from that.

Just stay analog... you know it makes sense! :wink:

Keith
 
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