Cornerstone Monitor - missing blue color

[John Dough]

I'm trying to repair my cornerstone monitor which is missing the color blue.

I've tracked it down to a driver chip (I think) - VPS10 (CRT Display video
amplifier)

If I disconnect the input pin (pin 10) the signal is the same shape as the
other two colors - red and green. The moment I connect the input back the
amplitute of the signal almost halves. I've checked the output pins as I
thought it might be pulling the input down - but no go. All
resistors/caps/diode check out ok.

Does it sound like the chip is faulty - is this a common fault? Can anyone
recommend a replacement - the local exeltroniucs shop doesnt stock them

 

[Jerry G.]

I would try the IC at the point where you are, and from your description. I
have not serviced the particular make and model of monitor you have, but
have had similar experience with others.

--

Jerry G.
======


I'm trying to repair my cornerstone monitor which is missing the color blue.

I've tracked it down to a driver chip (I think) - VPS10 (CRT Display video
amplifier)

If I disconnect the input pin (pin 10) the signal is the same shape as the
other two colors - red and green. The moment I connect the input back the
amplitute of the signal almost halves. I've checked the output pins as I
thought it might be pulling the input down - but no go. All
resistors/caps/diode check out ok.

Does it sound like the chip is faulty - is this a common fault? Can anyone
recommend a replacement - the local exeltroniucs shop doesnt stock them

 

[Techforce]

They do have a history of fail, you can purchase here: http://www.ljecc.com/


| I'm trying to repair my cornerstone monitor which is missing the color
blue.
|
| I've tracked it down to a driver chip (I think) - VPS10 (CRT Display video
| amplifier)
|
| If I disconnect the input pin (pin 10) the signal is the same shape as the
| other two colors - red and green. The moment I connect the input back the
| amplitute of the signal almost halves. I've checked the output pins as I
| thought it might be pulling the input down - but no go. All
| resistors/caps/diode check out ok.
|
| Does it sound like the chip is faulty - is this a common fault? Can anyone
| recommend a replacement - the local exeltroniucs shop doesnt stock them
|
|

 

[John Dough]

Thanks - managed to source a chip - replaced it, and it works like a bomb!!