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#299645 - 23/06/2007 12:19 Multiple Problems: Half VFD - Malfunctioning Buttons - Other Weirdness
JeepBastard
enthusiast

Registered: 08/09/1999
Posts: 364
Loc: Brooklyn
Hi - I started repairing my Empeg which can be see in its broken glory on this thread

The screen was gone and the cable burnt out, but the buttons worked fine - so I navigated the menus by memory.

I got a new ribbon cable that connects the front panel card to the motherboard and I re-soldered the screen back to the front panel. This was hard because I have soldered the board so many times for a new screen that some of the holes are bleeding together.
When it first came up - the screen had a funny garbled look to it and the buttons began to fail. So i looked at this FAQ Entry and saw that i probably blew the display fuse they mentioned. in fact , it probably has been blown for some time - the display wasn't garbled before - but it was dim and I had to press the buttons a ton of times to get it to get from booting up to get to the player mode - but it was legible at night - i never noticed before. I tested the fuse with the multi-meter - and of course it was dead.

So I went and replaced the fuse - actually with kind of a kludge - I used a fast acting 1 amp fuse from radio shack - not the surface mount kind tho. Unfortunately - in testing the unit - i believed that I soldered some of the display leads (the power ones) together trying to find a solution before I found out about the fuse ---

I put it into the motherboard and fired her up. Boom! Bright screen and the unit started right up past bootup into the player - but now i had HALF A VFD as mentioned here in the FAQ here.. The weird part is that sometimes the screen comes back on from Half VFD - and you see the full screen - but its garbled - OR it blanks out completely and you see bright red lines which I never saw before but is also mentioned in the FAQ here.

I would just live in shame and use half the VFD - but the buttons dont work - they exhibit weird behavior.

- For a small window - sometimes they work just as advertised.
- Sometimes pressing the rotary knob sends the player into a loop shuttling between all the modes (aux/turner/player/etc) only a reboot or a two button press stops it.
- Sometimes they dont work at all (which is most of the time)
- Sometimes you press two of the buttons - and they will put the player into super fast rewind or super fast forward - shuttling thru a 3 minute song in 2 seconds. Only a reboot stops it.

Sorry for the lengthy post, but I really enjoy my EMPEG and have been using it everyday since it came out and I'd love to find a way to diagnose the problem and fix it - I soldered in about 3 screens before without problems, and fixed many things on the motherboard and put together pcats turner - I'm by no means an expert at this stuff, but I am not afraid to take another crack at the board to fix it any help is super-duper appreciated.



Update - The button weirdness is alleviated when i take the screws out and press the front display metal braces all the way against the front of the metal frame of the unit. I guess something isn't grounded right or something is touching and shorting - shoved a piece of rubber in between the motherboard and the display card - and now I have my buttons back - now at least I can listen to music till a solution appears for my Half VFD!
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Mark I + Mark IIa | Jeep 97 TJ
my current blog

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#299646 - 23/06/2007 13:37 Re: Multiple Problems: Half VFD - Malfunctioning Buttons - Other Weird [Re: JeepBastard]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31565
Loc: Seattle, WA
Bright red cathode filament wires may be a bad sign. They should be fairly dim.

Based on your description, you've got some sort of intermittent break and/or intermittent shortout that is alleviated by changing the amount of flex or pressure on the display board. That's going to take some work to locate...

I don't think a solution is going to appear for the half-vfd, unless by "solution" you mean "new VFD from Noritake".
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Tony Fabris

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