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Old 28th Apr 2020, 4:09 am   #53
PortugalTV
Tetrode
 
Join Date: Nov 2018
Location: Serzedo, Portugal.
Posts: 83
Default Re: B&O Capri 606 TV (17") restoration

very nice shcematic!
according to the schematic you should have around 60vdc on the crt cathode
g1 also gets its voltage from the 180v B source through 3.3k then 220k then the brightness potentiometer then a 100k resistor. It should be lower than the cathode , the schematic doesnt specify but usually its around 30v difference but it changes as you adjust brightness
after the pot you see the point marked in red as 78 and then 175 that is the retrace suppresiion line and it connects both to the flyback and to the vertical output transformer.


oa95 is a fast recovery germanium diode so it should work, that tekade diode is probably germanium so it should measure 300mv and not the usual 600mv on the meter, but if it tests open, then replace it

the pcl 84 video amp tube's pentode section is used for video amplification and the triode section for the AGC voltage generation

the lack of video and higher voltage on the anode of the pcl84 suggests the tube is not conducting, check the cathode resistor for any altered value, they get preety hot, while there check the 1n bypass cap
there is not much to go wrong there its a very minimalistic circuit and the schematic is good, there are schematics wichare hard to read, its not the case

you have a selenium recifier oon the power supply, thats the reason the B+ drops a bit...its probably tired...40v lower should not matter much but when the set is working OK consider replacing it with a silicon diode in series with a dropping resistor, dont waste time on that right now

it was good that you left the "mustard" type capacitors alone. only seen one shorted in my lifetime. never saw them in green though

Last edited by PortugalTV; 28th Apr 2020 at 4:35 am.
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