Pentranic 1019

[Robert Bailey]

Ok i have looked all over the net and can't find anything on the chassis.
it has a CH-201, found a CH-203 but it isn't close. the 201 doesnt have any IC's.

came out of a cherry master

The screen has a great picture with no burn in. but I have a wave going from top to bottom
that is real slow...takes several seconds to travel. I replaced all the caps with the same value I took out, and I ordered and replaced the big filter cap and nothing changed.

anybody have any pointers for this chassis or maybe a manual.
Thanks
Robert

 

[Dr Zero]

Ok i have looked all over the net and can't find anything on the chassis.
it has a CH-201, found a CH-203 but it isn't close. the 201 doesnt have any IC's.

came out of a cherry master

The screen has a great picture with no burn in. but I have a wave going from top to bottom
that is real slow...takes several seconds to travel. I replaced all the caps with the same value I took out, and I ordered and replaced the big filter cap and nothing changed.

anybody have any pointers for this chassis or maybe a manual.
Thanks
Robert

Try Rick Nieman at www.niemandisplays.com in Canada he is a nice fellow helped me with my pentranic.

 

[Robert Bailey]

Got up early this morning to see if i could figure this out.

I can't even find the B+ voltage, and the horz width is stretched and the adj coil moves the image very little. I am thinking it is in the horz circuit but without prints....I am lost.

I have fully capped it with what came off the board and even replaced the big filter cap and it didn't change a thing

ahhhhhhgggggg

 

[KenLayton]

Did you check with Rick Nieman yet?

 

[Robert Bailey]

Did you check with Rick Nieman yet?

sent an email this morning, i am behind on everything

 

[Robert Bailey]

Got a manual from rick on a pentranic chassis, and an answer to the problem, as I suspected it is in the +B voltage circuit somewhere. I cant adjust the width hardly at all.

Bad thing is the manual he sent is for a ch-203 and I have a ch-201 which has no IC's on it at all. guess I will have to hunt an peck or just order a replacement.

 

[Robert Bailey]

finally got some time to look at the chassis. I measured the +b voltage and it is 153 vdc.
turned the +b pot and it doesnt change the voltage, I pulled the pot , measured ok, tested all the diodes and transistors, gave up for the night, taking the chassis to the office to see if the guys that work in our electronic labs can figure out what I am missing.

 

[Robert Bailey]

well i offically give up on this dang thing. I checked all the diodes and transistors in the +b circuit and they all look good, the difference between this and a wells gardner is way off.

get 154 volts on the +b but no shutdown...dont think it has one.

looks like the c2555 get 0 volts but the transistor feeding the darlington isnt getting enough voltage to turn it on .4-.5 when adjusting the pot.

on my chassis the upper part of the pot and the wiper are tied together where as the only schematic online for the ch-203 isnt.......

 

[jjhudgins]

well i offically give up on this dang thing. I checked all the diodes and transistors in the +b circuit and they all look good, the difference between this and a wells gardner is way off.

get 154 volts on the +b but no shutdown...dont think it has one.

looks like the c2555 get 0 volts but the transistor feeding the darlington isnt getting enough voltage to turn it on .4-.5 when adjusting the pot.

on my chassis the upper part of the pot and the wiper are tied together where as the only schematic online for the ch-203 isnt.......

Is this a low ohm chassis? Wondering if I can replace with a k7000.

 

[jjhudgins]

Had some progress on this.
Symptom: Pops 1.25 fuse
Found 3 caps completely open. 1 in power section.
Found HOT Shorted. Both outer legs in diode mode are shorted together. HOT is a 2SC5250. Pretty sure I did it right.
Preformed light bulb test and got about 113. I have no idea what it is suppose to be but the pot is painted red and it is set perfectly. Once I replace all the caps Im sure the B+ will improve. However who knows what it is suppose to be. Will update once HOT gets here.

 

[jjhudgins]

Curious if the FJL6920 HOT would work.

 

[jjhudgins]

It lives but the sync is off. Not sure why.

 

[jjhudgins]

Is this a low ohm chassis? Wondering if I can replace with a k7000.

This must be a high ohm chassis