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Bluechen

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Hey, my Blast looks like this, is there a way to adjust this or is something broken ?

Thank you
 

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I now assume that it only works if I do this while everything is turned on right ?
 
I now assume that it only works if I do this while everything is turned on right ?
Yes, and it’s recommended that you pull the monitor out while you adjust it. It’s too difficult to adjust that spc15 pot while it’s still mounted to the cab. I’ve done it before with it still mounted and it’s not fun.
 
I now assume that it only works if I do this while everything is turned on right ?
No you can do the adjustment with the monitor off but its a little more annoying to do it that way.
SPC is the Pin Cushion adjustment the MS2930 has that adjustment for 15/24/31khz resolution modes.

The phenomenon your experiencing is what we call pin cushion and it will make the image bow or curve on the left and right sides uniformally.

If changing this pot makes zero difference then you have another issue somewhere and may want to suspect a bad SPC potentiometer. You can verify if the pot is not damaged visually or pull the chassis and measure the resistance of the adjustment pot. Thats a later down the road thing just adjust it for now see if it helps
 
Thank you for your message. I have now turned on the SPC and SPC15 but it changes absolutely nothing. I think I can't get around taking out the whole monitor and then turning the pots directly when the monitor is on.
 
I took the monitor out and then tried to adjust it. I noticed that 4 pots are dead. Among others SPC and SPC15. No response.
 
Those pots can get damaged or rusted/corroded sometimes. Or even have bad solder joints.

Your next best step is gonna be to find out what value those pots are and take a multimeter and measure the ohms.

Check between the outside two pins of the pot first to see the overall resistance and then adjust the pot and see what the values change between the center pin.

If the solder joints are bad reflow those with new solder, if the pot looks visibly damaged or rusted you probably need to replace it. This may be why your pincushion is way off to begin with if the resistance of that pot is wrong or the pot is damaged.

Another member here might be able to assist on this further as for what the values should be or which replacement to buy.

If the pots seem fine in testing and or replacing them makes no difference then you need to start looking further down the line in the circuit for troubles.
 
I will recap the whole board and change all pots. Then let's see if that did anything. Can someone tell me which pots I need with which values ?
 
Did you ever find a replacement for those pots? The SPC pot on mine is labeled 222 which I believe is 2.2 KOhms but I can’t find a good match
 
I sent this to a professional in Germany. I will ask him and when I know where to get the parts I will write it here. Please give me a few days.
 
I sent this to a professional in Germany. I will ask him and when I know where to get the parts I will write it here. Please give me a few days.
Of course, take your time.

My SPC pot cracked and the screen looks wonky now.

I found a similar 2.2k pot from a supply company. Should be here next week and I’ll pop it in and see what happens.
 
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