TAM Not Booting Up

[Mac-in-us]

Hello, I recently acquired a nice looking Twentieth Anniversary Macintosh from my friend.

Apparently it looks good, but it won't boot up anyways--sort of though.

The computer chimes and lights up green LED at the bottom, but the screen is just white. There is no cursor, happy mac, x floppy disk--just plain white screen. 

After booting, the computer seems to read HDD, and alert sound effect comes out from speaker approximately 3 minutes later. I heard the screeching noise from the first booting but that went OK after that booting.

CUDA reset button did not work.

The PRAM reset did not work.

Reseating the DRAM did not work.

Removing PCI expansion board and SONNET G3 board also did not work. Oddly enough, the computer will not boot with the SONNET board and PCI board installed.

Since the screen doesn't work, I can't get much informations out of this.

All of the capacitors look fine.

Btw later I accidentally connected 220V to 110V PSU and heard a pop sound from the Boss. I hope only the fuse has blown, or I'll need to get a replacement unit...

Someone here in Korea is selling a computer 

 

[bibilit]

hi,

I will remove all cards first.

I had the same problem once, was a screen issue, replaced with a Powerbook 3400's one.

 

[Byrd]

Short of blowing the PSU (!), the LCD needs replacement from a donor PowerBook 3400. There is also a board that runs from the TAM motherboard to LCD (some sort of LVDS or analog to digital converter) that can also go faulty, but usually have artifacts or lines on screen instead of just white.

 

[techknight]

its a little fuse that popped on the LCD itself. 

 

[glay78]

Try this, disconnect the HDD ribbon and try booting up.