color classic grey screen

[falen6]

Hi folks.

Got a color classic recently - powered it on and it chimed and gave the display of the flashing disk icon
the logic board was in a terrible state - amazed it even chimed.

recapped the board with tants and gave the board a much needed clean

put it back in and powered it on - chimed and display

took out the logic board and re inserted it a few times and the hard drive was working , booted all the way to desktop

powered it on later on and all i get is a grey screen ..BUT the machine boots to the desktop and plays some sound (same sound it played when it got to the desktop when the display worked)

so i have a CC thats working but the display is grey

i thought it would be the memory chips , but if that was the case then the machine would not continue with the boot

have not opened up the machine to even look at the analog board

am i just unlucky that after the recap initally worked , the analog board decided to act up !!

 

[falen6]

have read that the 256k vram is the 2 chips next to the vram expansion slot - ive checked and reflowed them - still the same - i guess this is why the machine is booting regardless of the video problem

took the back cover off to have a look - machine is very clean inside - checked the big slot connector for the logic board and it appears solid and clean

i have replaced every cap one by one from the recap just in case one was bad , but still the same

machine is responding to keyboard commands to shut down , to restart

its just a video issue

volume and brightness controls on the front all working

the machine came with no ram or vram expansion simms

have gone over every solder connection with powerful magnafying glass......... cant see whats the problem is

the board is spotless now , front and back

 

[falen6]

got a display with pram reset , by pressing command , option , P,R and power at the same time ........ but with artifacts on the display as the mouse moves


i dont have a battery installed on logic board as i dont have a new one..........

machine powers with no battery installed - have read many conflicting opinions with batteries on CC

 

[falen6]

still have the problem - hasnt given a display for last few hours - pram reset not making any difference now

ive checked all the caps with other new caps , and soldering is clean and accurate

the amount of cap goo that was on this board when i got it was unreal

i used liquid hand soap , toothbrush , sink and water - gently cleaned entire board , suds galore ! , rinsed , repeated 3 times

used acetone all around caps removed

im wondering if its possible the cap goo ended up under chips and is causing problems

im back to power on , chime , grey screen , then hearing harddrive booting to desktop playing some silly sound........ but just a greay screen and no mouse pointer

wtf !!!

 

[falen6]

aparently this is an unsolved problem for CC's reading this thread

Color Classic motherboard woes

I'm picking up a project I've been sitting on for some time. I have a Color Classic that doesn't want to boot. When I press the power key, the light will come on and the hard drive/fan will spin up, but there's no chime or image on the CRT. It's definitely not trying to boot because I'm not...

tinkerdifferent.com

same problem , except im getting a chime and the machine is booting ......... but screen is just grey , no mouse

has ANYBODY !!!!! had this problem .......... jesus its driving me mad - it has to be something stupid

so far - i have taken off the old caps , removes old solder , no pads damaged , washed the board over and over , then with acetone , then with iso , recapped with tants .......... i get grey screen ........... then i replaced the caps one by one with other new ones ........

on the edge connector i have remove all the old solder and replaced with new solder

have gone over all the vias i can find reflowing their solder

reseated the 2 roms a dozen times

checked the analog for voltages by soldering on wires to various points to read the voltages

everything is as it should be


this dam thing was working when i first got it

ive recapped dozens of macs ............. this has me lost


ANYBODY !!!!!!!!!!!!!!!

 

[falen6]

went through everything in this thread , but it didnt help me

might help someone else though

Post in thread 'Color Classic no power issue debunked!'

Jun 10, 2015

I just got a Color Classic which had the same problem--could hear a PSU noise when turning on the hard power, but no response to the keyboard power button. The caps actually don't look that bad (much better than my SE/30 in original condition) but I started looking at the vias around the crystal.

The via that dougg3 highlighted is fine on my board, but the one just to the left of it was corroded on the bottom of the board (pretty weird!). It's pretty obvious on that right side of C56.



Luckily that via just goes to ground, I added a wire to the battery ground...

• mrpippy

 

[bibilit]

The Egret is most of the time the issue

 

[falen6]

I took it off , cleaned the area with iso , checked the continuity between all the vias under the chip to their local pads ........ all seems fine


just took off U5 and did the same , all seems fine ......... put it all back and still grey screen

the video memory is seperate from the onboard 4mb

has to be something in there

gonna make a short vid

this is doing my head in !!!