Hot CLUT DAC on LCII ok?

[RetroTechGuy]

I have an LC II logic board that won’t show an image. I’ve seen that others have had the same problems, but I’ve recapped the board and tried with a PRAM battery.

The hard drive spins up and the monitor leaves stand-by but there is no chime.

I’ve noticed that the UJ10 chip next to the video connector gets really hot, too hot to touch after a while. This chip is also labeled as CLUT DAC.

Does anyone know of this is normal? I’m considering trying to replace this chip if it doesn’t run red-hot on other machines.

 

[melkab]

Did you ever find out if this chip being hot was OK or not? Have an LC II with the exact same symptoms (no chime, no video) and this chip is hot on my machine too.

 

[RetroTechGuy]

Did you ever find out if this chip being hot was OK or not? Have an LC II with the exact same symptoms (no chime, no video) and this chip is hot on my machine too.

Unfortunately I never got around to it. Do tell if you find the culprit!

 

[GiGaBiTe]

In normal operation, those chips get mildly warm, but not burning hot. I suspect your chip is most likely dead.

 

[melkab]

Sooo almost a year later I can report that my LC II is now working again. Seems this chip runs hot when the video subsystem is not starting properly. In the end it was the EGRET and a whole bunch of other small chips I had to resolder/replace, the UJ10 was fine. So chances are yours is too.