RCA RPTV CTC169PT wont't power up

I have a ctc169pt chassis that won't power up this unit has been worked on before as it appears that the H out transistor & the PS IC have either been replaced or resoldered.

H out transistor appears to be ok (not shorted or open) in circuit, however there is no voltage present at E C or B in stand by mode.

I checked a the diodes coming off the mains, they test ok out of circuit, I replaced CR4118 even though it tested ok.

still no standby voltage. I checked the big stand up power resister that comes off the mains (1.8 ohm 15 W) & it was open I replaced the the resistor, applied power & measured for voltage & no difference, I checked the resister again & found the new one was now open, no spark,smoke or heat, it just quietly opened.

I have no experience with this chassis or any schematics for it.

does anyone have any ideas what the problem might be ?

Thanks in advance, Roger

Reply to
JoeNeZZ
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Shorted power supply diodes or switched regulator output transistor. If the transistor is shorted, replace the drive ic and check the electrolytic capacitors around it for high esr. Replace all that have high esr. Chuck

Reply to
Chuck

Reply to
JoeNeZZ

I traced the problem to a shorted Q37F on the heat sink of the deflection board Does anyone have an RCA part number & or a cross for this part the number on the part reads "R138" but my part supplier has no listing of it nore does NTE so it is probably an RCA house number.

Thanks, Roger

JoeNeZZ wrote:

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JoeNeZZ

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