Sharp Image SI 629DS-R high pitch squeal

telmnstr

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Trying to repair Sharp Image 629DS-R chassis to shove onto a tube that was used with some other Kortek board. Friend buffet gave us the chassis as they are medium res 25khz selectable (Cruisin Exotica is the game)

Friend recapped it. Fully recapped.

Set to 25khz.

Powering up monitor, it emits a loud high frequency squeal.

No picture.

Upon removing power, see a white flash collapse on the screen.

Any thoughts?


(Also, took lots of notes on the caps and drew up a vector cap map that we're going to release once we get all the info together.)
 
Maybe check the brightness..it could be turned up too high.
 
Good news, issue was the brightness was too low so I didn't see the image on the screen.

The high pitch squeal was a result of the horizontal/vertical holds being adjusted too far off. Once they are corrected the image is sort of in place.

The chassis is configured as 25khz, and I have the jumper on the "N" instead of "W" to hopefully set it to narrow.

The image from the game (Crusin Exotica) doesn't fit on the monitor though. I

Friend suggested I verify the B+ voltage is good. So now I need to figure out what the voltage should be on this chassis connected to a 27" tube. He suggested that the B+ voltage being off can result in the image being too wide or narrow. I guess it throws off all of the analog circuitry. I'm not sure what size of a tube the chassis came from.


Also, depending on the settings on the remote board, there is arc happening in the plastic CRT socket. So I'm going to tear that down / replace it and make sure that the arcing stops before anything further to avoid risk of damage to workingish chassis board.
 
The CRT socket has a spark gap set up in it on purpose. It seems to dump the power to ground. I'm guessing power is too high if this is happening.
 
does any body know what the b+ is suposed to be. it is around 200 and wont adjust down any further.

Peace
Buffett
 
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