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Color Classic - now with a purple screen

mraroid

mraroid

6502
Hi....

My Color Classic has always had a perfect screen.  No bleeding of colors, no off colors, just perfect in every way.

While I was running it today, I rebooted and it booted to a purple screen.  Everything worked, except everything had a purple shade to it.  I rebooted again and same thing happened.  I shut it down, then did a cold boot and same thing happened.

My logic board has just been re cap'ed and so has my analog board.  I do not have any extra boards to swap out.  I did drop in my older hard drive and that was not it.

After that, I took the case off to see if I had any loose wires or anything.  I found nothing visibly disconnected or not plugged in correctly.  I sure hope it is not my CRT.

Any suggestions on where to start looking for trouble?

Thanks in advance

jack

 
try sliding the MB in and out once.   also there could be dust on the AB, edge connector,   might want to run that in and out once as well.

 
Did you recap the AB? There are known leakers in the video amplifier section. Also the pots need cleaned/worked back and forth. Also, did you check the solder joints on the CRT Neck board? You have to remove the shields to do so. If those go bad, youll get this problem. 

ALL, and i mean ALL EVERY SINGLE ONE of them capacitors have to be changed out in the AB. Not just a little handful quick fix shotgun thing. I mean ALL OF THEM.... Mainly the ones hiding in the shielded video amplifier circuit. 

 
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Uniserver....  Tried that already. Thoughts?  techknight - the analog board just came back from being re cap'ed.  Do you think the issue is in the analog board?

jack

 
I had the same symptoms with my CC - and it was a dry joint on the analog board.

The underside of the board where the shielded video amps sit had a dry joint. If you look on http://s14.postimg.org/6khbmega9/CC_Analog_Checklist.jpg there are two parts to the shielded section near the bottom of the photo. The device at the top of the smaller (lower) fenced area had the dry joint on the other side of the board.

 
1. have you tried what i suggested?

2. were you rough on the CRT neck board?

3. Tap or wiggle the crt knock board while its on and see if there is any color fluctuation, that will be tell tale of any broke solder joints from rough handeling.

weren't you the same guy that cut the HV wire going to the tube instead of removing the suction cup?

and you were just going to splice the wire or something?

 
uniserver....

1) Yes, I tried what you suggested.
2) No, I am not rough with my electronics

3) Tried that.

I sent you my good, working, analog board  from my working Color Classic.  You said you would replace the bad caps. You told me old solder joints some time fail and you fix them.  It failed with in 48 hours of returning to me.  And no, I had no cut wires in my color classic analog board.  I know enough electronics to not man handle anything.  I re assemble the color classic on my work bench with a static wrist band on.

I rebuild old vacuum tube motion picture amplifiers for a hobby.  So I know how to assemble and re assemble correctly.  I do not know modern electronics with chips and flat packs.

I took the color classic apart again yesterday afternoon.  I pulled the analog board.  Just eyeballing it I could not see any cracks in it.  I use compressed air on the socket before I plugged it back in.

After I re assembled it, I still have to same issue.  I need to trouble shoot this problem in or out of the analog board.

Did you replace all the bad capacitors in this analog board?

jack

 
Sounds good , well its probably to best to take care of customer service issue off the forum... 

If you want to send it back, Ill see what i can do with it buddy.  and for your troubles, ill even send back a cap kit for that CC board your working on, and a parts board with Q1 and other parts you might need for it.  Sounds to me like maybe a cap got installed backwards, or a wire/solder joint that connects to the crt neck board.

 
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IMG_2108.JPG

IMG_2112.JPG

gotta love pots that make an iffy mechanical/electrical connection in vintage stuff.

work em a little and then all is well.

 
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this is the dark side of doing what i do. 

I sent you my good, working, analog board  from my working Color Classic.  You said you would replace the bad caps.  It failed with in 48 hours of returning to me.
Click to expand...
 
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Great news Uniserver.  It sounds like the beast is alive again!  I could not be any more happy with your technical abilities and your customer service.  I would not trust any of my Mac repair or re cap'ing to any one else.

Can you tell me if the adjustment tool for the pots are a flat blade or a 6 sided tool?  And the tool size?  I would like to buy the correct tool for my color classic.

Thanks again.

jack

 
[SIZE=10pt]Note: [/SIZE][SIZE=10pt]The controls on this monitor require a short hex-head plastic tool to make adjustments. If the tool[/SIZE]

 

[SIZE=10pt]Adjustments [/SIZE]is long or too thin, it will be too flexible, which will make fine adjustments difficult. Use a short, rigid, hex-head plastic tool to minimize flexing.
[SIZE=10pt]Warning: [/SIZE][SIZE=10pt]Donotuse metal alignment tools—they are a shock hazard.[/SIZE]
Click to expand...
From Apple service manual

pic.jpg

 
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uniserver said:
this is the dark side of doing what i do. 
Click to expand...

You Touch It, You Own It!!!

Tech support sucks (100x more when you work for yourself) where people expect you to know everything and for all problems to be resolved absolutely perfectly 100% of the time, and god help you if it doesn't. Well, things can go wrong, even when you fix them. Ever taken your car to the shop to get fixed and it doesn't seem right when you get it back? Been there. 

 
slomacuser said:
From Apple service manual

attachicon.gif
pic.jpg
Click to expand...
Thanks!  I will look for tools like the drawing.  I can buy several sizes and hope one fits.  This narrows it down a great deal.

 
MJ313 said:
You Touch It, You Own It!!!

Tech support sucks (100x more when you work for yourself) where people expect you to know everything and for all problems to be resolved absolutely perfectly 100% of the time, and god help you if it doesn't. Well, things can go wrong, even when you fix them. Ever taken your car to the shop to get fixed and it doesn't seem right when you get it back? Been there. 
Click to expand...
True, but.....

Uniserver has done an outstanding job for me.  

I bought a re cap'ed CCII logic board (not from anyone here).  Uniserver asked that I send that to him as well (he has never worked on that logic board).  I did not suspect any trouble in the logic board.  But Uniserver found several problems.  He washed it and re cap'ed and it is working fine now. I think it is sometimes hard to find someone with good technical abilities plus good costumer service. Uniserver has both.

I don't quibble with Uniserver about payments. He tells me what IO him, and I pay him.

jack

 
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