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Old 01-15-2017, 04:35 PM
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mr_fixer mr_fixer is offline
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Join Date: Jul 2007
Location: Tennessee USA
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Ok, i disconnected the hot and flyback from the 130v supply, voltage went up to 138 v, I connected a small 40w lightbulb from 130v to ground for a load, volts dropped to 27v. Horizontal driver supply voltage is unchanged at 6-7 volts where 33 is expected.
hmmmm. resistors that drop the 33 supply from 312 volts are good and there is a diode that somehow is supposed to bridge the 2x20k resistors and 7 volts worth of zener diodes to ground. I'm not sure how a regular diode can act like a resistor, any thoughts?
Logan

Quote:
Originally Posted by zeno View Post
Unhook the C of the HOT & see if the voltage comes up. Also
do the heat test of the HOT.
Dont forget you are working with 3 grounds on this set.
Hot gnd for the primary of the PS
Cold ground the chassis ground / PS secondary.
I dont think this one does but some sets also had another ground for the
hoz osc/out.
CRT ground. Most NAPs do NOT ground the CRT dag as normal sets.
We used to just grab the CRT ground but that dont work on these.

73 Zeno
LFOD !
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