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#254503 - 17/04/2005 17:57 Help: Another Dim Display
gleno
new poster

Registered: 17/04/2005
Posts: 3
Loc: Littleton, CO
I've got a Mk2 player running the developer build of 2.00 and Hijack 422. Since this problem involves the display, I should mention that I did my own upgrade to add illuminated buttons and knob. (I even cast my own buttons - but that's a different story...) I did this a long time ago, so it's not a new upgrade problem, although I have no idea if it is related to my current problem. I don't think it's relevant, but the rotary encoder has been acting up for a while as well, volume changes using the knob are frequently erratic and sudden. The only other change I've made to the player is the negative spike fix.

I've read thru the FAQ and searched the previous threads for any help, but haven't found quite what I need.

About a week ago, I added a second drive to my player. I now have 60GB+40GB. I needed the space as I now have ~20,000 songs on it. I was listening to my added music at lunchtime on Thursday when I noticed the display was blank and my buttons were no longer illuminated. Everything else still worked, there was just no display and no button lights. That night on the way home from work, I noticed that the display was still there just VERY dim.

I came here and started searching the FAQ and previous posts. I opened the player and checked the fuses - they were (and still are) good. I also read about the potentially bad cap in the 60V regulator. When I measure the voltage at TP1, I get 12V. The capacitance meter in my DMM says the cap is 84nF. Sounds about right. In trying to determine the cause, I have removed the knob portion of the button illumination kit (to no effect). Next I looked at the ribbon cable. No frayed wires, and I get continuity on all the wires. I have noticed that if I apply enough pressure to the back of the display board to flex the middle about 1mm, the button LEDs turn on. If I do this while applying power, the VFD works normally and I get 60V at TP1. I can then release the pressure and the VFD will continue to work. However, the buttons will only work while the pressure is applied. It sounds to me like a physical connection problem rather than a failed component, but I have been unable to find it. I have tried retouching most of the solder joints (paying particular attention to the button mod, the MAX770 and the PIC decoupling caps)on the board with no success.

I would REALLY like to get this thing back in the car. I have used it almost every day since I got it in September of 2000!

Any ideas?

Thanks,
Glen
080000555 (Mk2 60+40 blue)

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#254504 - 17/04/2005 18:02 Re: Help: Another Dim Display [Re: gleno]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
Can we assume no one messed with you dimmer settings while you weren't looking? Though I don't think that would explain the buttons also dimming as they're controlled seperatly, right?

Matthew

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#254505 - 17/04/2005 20:49 Re: Help: Another Dim Display [Re: matthew_k]
gleno
new poster

Registered: 17/04/2005
Posts: 3
Loc: Littleton, CO
Okay, I tried to be thorough in my description of the steps I took, but I knew I would forget something. The dimmer was the very first thing I checked. Always start with the simplest thing first, right? The dimmer is set at 100%. This also happens in AC mode (so no dimmer setting) which is the only place I'm testing it at the moment, since it's mostly apart right now.

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#254506 - 18/04/2005 01:15 Re: Help: Another Dim Display [Re: gleno]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
I remember that my lit buttons started acting up at one point, and one of the side effects was a dim display. I also noticed that flexing the display changed things. I seem to recall that resoldering the various components related to the lit buttons, such as the resistor pack and the various bits on the knob board, fixed the problem.
_________________________
Tony Fabris

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#254507 - 20/04/2005 13:26 Re: Help: Another Dim Display [Re: tfabris]
gleno
new poster

Registered: 17/04/2005
Posts: 3
Loc: Littleton, CO
Well, I went through and resoldered everything again last night. I must have missed something the first time around because it seems to be working again now.

Thanks,
Glen

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