Color Classic Boot No Video/No Boot

[CompuNurd]

I recapped my Color Classic today, hoping that would at least make it turn on. I hit the power switch, nothing.. not a single click. Right, the keyboard power switch, duh! It fired up, but the screen didn't light up, and there was no chime. I could tell the flyback energized because I could feel the static near the screen, and I heard it fire up.

[/begin being a noob] There is a chip a tad bit larger than RAM on these machines, and the CC was missing it. I would guess this is the ROM, but can't find any sources to back up my theory. I popped one out of an LC, and put it in the CC, hoping I could get at least something. Nothing, sometimes it fired up with no screen, sometimes it didn't. What are these chips? Are they ROM? [/End being a noob]

I took it out, and it fired up again, but still no display. I reseated the video board and motherboard, still nothing. All it does is spin up the fan, hard disk, and initiate the floppy drive, there is no display, but I can hear the flyback energizing. What is happening here?

 

[EvilCapitalist]

The only open sockets on the motherboard would be RAM, VRAM (slightly larger and right next to the RAM), PDS, and FPU slot, all of which the machine can start without since it has 2MB RAM on the motherboard.

I know I saw somewhere that you could try and "jump start" the machine by taking out the motherboard, flicking the power switch (everything else will fire right up) and then quickly sliding the board back in.  I think I remember reading that someone had tried that to get around a bad power management chip.

 

[uniserver]

I think techkinght has 3 CC boards now on the shelf over there, All with same issue as yours.

I was going to send a CC board to Blob over at bomarc, then he could at least offer a CC Schematic set for purchase.

I just don't have an extra CC board to donate to the cause, right now.

There is a pretty big problem with CC boards still being dead after a re-cap... just like the 840av --- huge problems with those being still dead after a re-cap.

I have saved a couple CC boards by washing them really well, Drying with compressor, Then baking in the oven @ 190f for 20 min.

 

[rickrob]

I was going to send a CC board to Blob over at bomarc, then he could at least offer a CC Schematic set for purchase.

I just don't have an extra CC board to donate to the cause, right now.

Does the CC board need to be working?

 

[TheWhiteFalcon]

There is a pretty big problem with CC boards still being dead after a re-cap... just like the 840av --- huge problems with those being still dead after a re-cap.

You need to sprinkle them with the sweat of Michael Spindler.

Shots of this socket would help.

 

[CompuNurd]

Sounds like there is no way to fix it?

 

[Paralel]

I thought Bomarc was out of business? Or were rumors of demise greatly exaggerated?

 

[CompuNurd]

What's weird is it turns on, even with the motherboard installed using the keyboard power switch, but the only thing not happening is the CRT displaying anything. It doesn't even light up. I guess the motherboard is not giving a video signal, since the CRT energizes?

 

[Elfen]

Hard to say what this is without seeing a pic of the board.

 

[uniserver]

He said that it doesn't have to be working.

He has not done a RE since 2009. I asked him nicely. a month ago.   He said ok, but he will take his time with it and do it at his own pace.

And he doesn't want to put the board back together in-case he has to heat gun off some I/C's, So he doesn't want to worry about sending it back ether.

He's a good dude, you just gotta fly by his rules is all.  For what he does is almost boarder-lined madness anyways.

 

[rickrob]

Once I get my Color Classic repaired, I'd be happy to donate the original logic board. It had a little damage to a few components, but not bad. I still think it's repairable, but finding a CUDA chip for it would be tough.

I'm hoping there was no dmage to the LC550 board that was in it when the Analog board failed....

 

[CompuNurd]

You don't need a PRAM installed to start a CC do you?

 

[techknight]

Newp..

 

[CompuNurd]

Here's the board. I checked all the caps, and none are installed backwards.

The socket in question (see first post) is the VRAM slot on an LC, so I would assume it is the same for a CC? The VRAM is not present in the CC, so is that causing a problem?

 

[uniserver]

looks like your LO rom needs to be slid over.

 

[TheWhiteFalcon]

VRAM might help. The empty socket is for the FPU, which is related to performance.

 

[uniserver]

Nice thing about the CC is there is Ram and Vram soldered onboard.  So it will still work with out any simms installed.

Kinda the same reason I really like the LC-III

 

[techknight]

Yea your ROM position is wrong.

 

[Elfen]

Third  on your Low ROM Chip position. It's off by 1 hole.