Nanao ms8 29 monitor shuts down

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MostroVeneno
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Nanao ms8 29 monitor shuts down

Post by MostroVeneno » August 2nd, 2019, 3:00 am

Hi my friends,
I wanted to ask, my astro city monitor shuts down after 2 secs and an audible click. I measured at f902 the right voltage, one probe to the fuse and one to the frame monitor, is that right? And measured 94v, i adjusted the pot +B adj and changed, so i think the regulator is properly working. I've read this can be the HOT, i tried measuring it but i don't know if I'm doing right. I didn't desoldered and tried on diode mode if i could read 2 legs, the other being base. So....i don't really know what I'm doing but i would really like to get my first cab working. Anyone have advice about this?
Many thanks in advance!

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Re: Nanao ms8 29 monitor shuts down

Post by MostroVeneno » August 5th, 2019, 12:27 pm

Anyone can mention why would the monitor shut down if getting proper b+ voltage at f902?

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Re: Nanao ms8 29 monitor shuts down

Post by MostroVeneno » August 11th, 2019, 1:58 am

I swapped LA7832 from another chassis, and decreased B+ adj almost to the lowest. I got this image, and strange noise...[attachment=0]20190810_210412.jpg[/attachment]
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20190810_210412.jpg

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Re: Nanao ms8 29 monitor shuts down

Post by grantspain » August 11th, 2019, 3:03 am

you have no deflection and it looks like a bad yoke from the photo

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Re: Nanao ms8 29 monitor shuts down

Post by MostroVeneno » August 11th, 2019, 3:16 am

Thanks @grantspain for the reply, where can i start to fix deflection problem ?

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Re: Nanao ms8 29 monitor shuts down

Post by grantspain » August 11th, 2019, 8:31 am

first you check for any cracks or broken tracks on the chassis, in particular around the flyback

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