Nanao MS9 no screen

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copados33
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Nanao MS9 no screen

Post by copados33 »

plays blind, I can hear high current noise (a chirp first then an stable low pitched hum ) after powering it ON but no neck glow, meassured B+ at TP2 at 76volts DC, when powering OFF it doesn't discharge the tube so I assume no current is passin to the CRT....

The neckboard has had its socket replaced at some point with another one taken from a MS8-29, but after further inspection on the solder side of the PCB I have found that some pins are not making contact because there are no solder pads:


4 and 12 pads are tottally gone, while the others look bad, checked ok for continuity, I tried to follow where these pins with missing solder pads go but found nothing??...where do these go?

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nem
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Re: Nanao MS9 no screen

Post by nem »

copados33 wrote: September 2nd, 2022, 8:09 pmI tried to follow where these pins with missing solder pads go but found nothing??...where do these go?

They're unused.
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Re: Nanao MS9 no screen

Post by copados33 »

Its not the flyback, the MS9 guide says I must check Q908, Q904 and ZD901 but I cannot find where those are, ZD901 should be on the parts side but its empty there , unless they are on the solder side where all I can see there is those small black mosfet-like SMD components...
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Re: Nanao MS9 no screen

Post by Eddhorse »

Whats the chassis model number?
Mine is 05A00675B1
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Re: Nanao MS9 no screen

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This one is 05A00675C1
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Re: Nanao MS9 no screen

Post by Eddhorse »

Ah so that's the Nanao MS9-29A Chassis #05A00675C1

Here's the cap list if you need it :


Neckboard

10uF 250v C332

Mainboard

1uF 50v C102/C554/C556
2.2uF 50v C211/C212/C213/C411
10uF 35v C957
10uF 50v C455/C456/C457
10uF 250v C513
22uF 50v C107/C222/C451/C459/C458
47uF 16v C201/C202/C203/C561/C958
47uF 160v C953
100uF 10v C562
100uF 16v C221
100uF 35v C407/C408/C409/C503
100uF 160v C515
180uF 100v C951
220uF 25v C955
220uF 100v C952
470uF 16v C220/C402
680uF 10v C956
680uF 35v C954
1000uF 35v C406
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