Xm501 b&w

FlashbaxArcade

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i'm trying to capkit this XM501 B&W monitor with Bob's capkit but the C16 on mine looks like a non-polarized and his is polarized??? does it matter direction on C16?

also, i can't find C51?

thanks
Kelly
 
C16 has polarity marked on the chassis, and is not listed as NP in the parts listing, so i'd say it should be polarized.

C51 is located on the bottom of the frame right next to the chassis.....

http://arcarc.xmission.com/PDF_Moni...19in) and XM701-10 (23in) Service Manual.pdf

there is NOT a polarity(+) marked on my chassis for C16...neither is C17 next to it! that's why i asked.

gotcha on the C51, thanks! i just pulled chassis(easy) not whole monitor out....this sucks gettin to that one!!!
 
ok, what did i do this time...............

i did a capkit(before i even replaced C51, so i didn't take out monitor, just chassis pcb) and forgot to put back in the little green pcb that has C50 on it. turned it on and now get nothing on monitor! i do get guns in tube to light but can't hear HV i don't believe. put green pcb back on once i figured what i did and still nothing! also, found a pin/green wire came out of edge connector that goes to green pcb...pushed back in and still no change! what would that do if this pcb wasn't in when powered up?

can anyone steer me in a direction?
 
Did the monitor display a picture before the cap kit?

Recheck to make sure you connected everything...

yes, pick was fine but screen turned white after about 30 secs and chassis looked terrible....dusty as heck! so i just wanted to do a capkit and check cold joints! just went over the caps i repl and reflowed several things but no luck!

if you just take out the chassis there are no connections to make except pressing pcb down on the pins!
 
Yeah, I am familiar with these, I have four or five of them. Check the pins and sockets for cracked solder joints as well. You may have to remove the entire metal plate, but that'll give you an opportunity to replace that last cap.
 
update

i have checked the AC points and all the 73VAC are 155VAC, and 30VAC are 44VAC! 73VAC pins are same voltage as pin 2 it looks like. reading the top of 5V reg transistor(Q20) is 13VDC, and top of 73V reg transistor(Q16) is 99VDC! this is with neg lead on one of the chassis gnd pin 24.

first of all, am i reading AC/DC correctly?

second, if pins 2 and 3 are the same 155VAC, would that mean i have blown a transistor?
 
To read AC you need your meter across the hot and neutral leads. These are the two AC leads and it doesn't matter which lead is where.

The DC measurements are high. Are they adjustable with the pots?
 
To read AC you need your meter across the hot and neutral leads. These are the two AC leads and it doesn't matter which lead is where.

The DC measurements are high. Are they adjustable with the pots?

no, tried adjusting with the 73v reg adj pot barely got anything to change! but seems to a little.
 
Look at the top left corner of page 12 of the manual. That is where the B+ (73vdc) is generated. Test the components in that area, especially the resistors and transistors. You will have to pull a leg of most components in order to test them. You may as well test the Diodes as well...
 
i have checked the AC points and all the 73VAC are 155VAC, and 30VAC are 44VAC! 73VAC pins are same voltage as pin 2 it looks like. reading the top of 5V reg transistor(Q20) is 13VDC, and top of 73V reg transistor(Q16) is 99VDC! this is with neg lead on one of the chassis gnd pin 24.

first of all, am i reading AC/DC correctly?

Those readings should be DC...not AC

Edward
 
Those readings should be DC...not AC

Edward

thats what i thought but other threads said AC so thats what i checked and thats why i asked in earlier post!

i can adj to 73vdc but that also keeps pins 3 at same 73vdc! pin 7 is only at 22vdc. the voltage reg(Q20) on collector reads 12vdc, Q16 is 99vdc!

does "v. bias" change the 5vdc or the 30vdc? haven't messed with it yet.
 
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