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Date Posted: 02:14:30 11/24/01 Sat
Author: Adam
Subject: Re: These horrible little toaster boxes are stealing my sanity!!! (NEED HELP IDENTIFYING COMPONENTS)
In reply to: Stuart Bell 's message, "Re: These horrible little toaster boxes are stealing my sanity!!! (I go off the subject a little)" on 01:04:53 11/24/01 Sat

I took off the case back, which of course removes the fan. No screen image

Put case back on - Screen Image.

I noticed that if I whacked the CC, the image would 'ripple' as in dark waves would flow down the screen though I didn't lose the image.

Removed case back again - Image.

Flexed the Mac, i.e. Grabbed the top and wagged. This affected the image then it dissapeared.

Thought this was indicative of a soldering failure. Resoldered the 8-12 pin connection - No screen image.

It would appear that I am once again the owner of a dead Mystic.

Over the weeks, I have become more and more sure that something on the analog board isn't up to snuff and won't operate when forced up to 640x480. When I reversed the mod after the first unsuccesful attempt, I used the same soldering techniques and the Mac worked every time. In the period when the Mystic did work, something 'buzzed' inside. I don't know what as I had no way of listening in on inividual components (not without electrcuting myself) but I think it was from the flyback.

Some components on the a/b concern me because they look like they've been over-heated. They are:

RP15:
A resistor. This has a dob of glue on it that has burned to a crisp.

DL21 and DL22:
Look like diodes. The ares of the a/b around them (they are right next to each other) looks scorched. They are located on the component side of the analog board just in front of that little metal cage at the rear towards it's right (looking from the back) after it are a few largish capacitors.
If anyone has any idea of what these things are, PLEASE tell me.

So.. What to do? It's getting pretty late in the day, but my plan is this, moving from phase to phase as each fails to work:

PHASE I
Scrub the CC in it's entirety as suggested by Scott.
Completely redo the mod. from a clean slate perspective
Scrub the whole machine again

-If that fails as I suspect (remember, I used my 'standard techniques' to bring it back down to 512xwhatever and the machine was perfectly fine every time) it's

PHASE II
Replace RP15, DL21/22 (If I ever find out what they are)
Scrub CC a/b again

PHASE III
If practicable, replace the flyback (RS Components carries this kind of thing or so I'm told, but I have no idea what they cost, or if they'll have the right one -unlikely). If ever I'm going to blow the CC off the table, this is when.

PHASE IV
Get the other CC's a/b, modify it and stick it in to my Mystic (which has a better case). I'm quite reluctant to do this because if I stuff this up, I won't have a good analog board.

Of course, then they'll be the issue of what to do with the other CC since it will be sans a/b. I think I might try stuffing the guts of a 10" SVGA monitor and a PowerMac into it.

Thank you all for your continued help.

Regards,
Adam.

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