Did Cap Kit, Worked briefly,now FOCUS POT GLOWIN!

[modessitt]

Re: Did Cap Kit, FOCUS POT UPDATE

Yeah, do that. I've found what some of the B+ circuit voltage readings should be at various points, so perhaps we cna do some tests and see where it goes bad....

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok.. The spare R811 REMOVED from the parts chassis reads 57.5 Ohms set on 200k

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Also, I checked the didode setting on the empty holes on the parts chassis on that Q802.. All combos gave me an "L" reading... and I switched the leads around too.. just nothing.. I even went to the solder side to make sure I was getting a good contact

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Should I put one of the R811's back in if we are gonna be testing B+ voltages soon?

Can you confirm the yellow line on the R811 goes to the right when installed?

 

[modessitt]

Re: Did Cap Kit, FOCUS POT UPDATE

Yes put in R811. The direction doesn't matter on resistors...

I'll post the next one with the voltages we should be reading....

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok.. be right back...

 

[modessitt]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok. Assuming the monitor doesn't come working when you apply power, we'll start checking the B+ voltage again.

First off, check test point D091 again and try turning R812 (adjustment pot) to see if it does anything.

I remember you saying that the middle leg of Q552 was 12v, so that's good. You should have that same reading on the E of Q802.

The B of Q802 should read about 13.3v

The C of Q802 should read about 102.9v.

These are all DC volts btw.

If you put the black lead to the frame and the red lead on the outside case of Q801 (mounted to the left side of the frame), you should read about 150v.

See if any of that matches...

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok.. R811 is back in....

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok.. Here are results..

I tested the TPD091 for B+.. this time I could adjust it very little.. it went from 143.8 to 146.5 volts turning it from left to far right.

Q553 (you said Q552) does have 12 volts at that center leg I can reach.

Q802-- The right leg that goes to D805 shows 12.9 volts
The middle leg showed 142.6 volts! you said it should be only 13.3 volts? I prob. just have the B,C,E confused in my head still.

The left leg that goes to R807 shows 13.4 volts (like I said.. I prob. just got the labels confused still)

Q801 shows 155 volts, variables up and down very little...

 

[modessitt]

Re: Did Cap Kit, FOCUS POT UPDATE

Q553 (you said Q552) does have 12 volts at that center leg I can reach.

Actually I meant Q552. Q553 should have 6.3v on the center leg.

To eliminate the confusion of the BEC stuff, measure the voltage on the non-banded side of D805. the center leg of the adjustment pot, and the side of R808 connected to Q802....

Also, put your red lead on the outside case of Q551 (the HOT) and see what you've got....

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

I've never found a Q552.. The Q553 and 554 are just small square black objects right with 3 legs right?

Off to check the other stuff.. but looking at spare chassis.. no Q552 found..!

 

[modessitt]

Re: Did Cap Kit, FOCUS POT UPDATE

Q552 is located just to the right of D805.... near TPD091...

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok..

Q553 center leg is 12 DCV

D805 non banded side (this is a hard one.. this is different shaped.. sorta teardrop, red with the left side has a yellow paint dot.. ) so the other side without the yellow dot is 13 DCV

B+ adj pot.. center leg is 13.2 DCV

R808 side to Q802 is 144 DCV

HOT -- 146 DCV

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Q552 is located just to the right of D805.... near TPD091

Found it ! number was totally hidden.. The center leg of Q552 is 23 DCV

 

[modessitt]

Re: Did Cap Kit, FOCUS POT UPDATE

Q552 is located just to the right of D805.... near TPD091

Found it ! number was totally hidden.. The center leg of Q552 is 23 DCV

That seems high. Turn the monitor off and check R555 (390 ohm) and R556 (15 ohm). R555 should be dropping the 20v down to about 12.8v....

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Got to find R555 and 556 first ! What are these Q 451 and 452 marked V out ? anything helpful? still looking for the R555 and 556

 

[modessitt]

Re: Did Cap Kit, FOCUS POT UPDATE

Got to find R555 and 556 first ! What are these Q 451 and 452 marked V out ? anything helpful? still looking for the R555 and 556

They're directly above D805 and left of Q552...

BTW... the pic in the manual shows jumpers all over this board for the various voltages. Does yours have jumpers all over it? Perhaps we should make sure they are all there and connected properly. Have you done a cold-solder-joint inspection of this entire chassis?

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok..

R555 is 23.6
R556 is 22.8 DCV (this one was sticking perpendicular away from the board.. thru me off)

You asked about jumpers all over.. what should I be looking for? Just plain wires going from one hole to another with no resisters or didodes in the middle? There are some and are marked with a "J" and then a number.

As for cold solder inspections.. what am I looking for? I haven't used a magnifying glass (don't have one) to look for solder line cracks if thats what you mean.

 

[modessitt]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok, I meant for you to test the resistors with the monitor off with your meter on the ohm settings. You may have to pull them to get good readins. verify against the parts chassis.

Yeah, those are the jumpers I'm talking about. I looked at the picture of your chassis again, and they seem to be present, but whether they are all connected is another question.

As for cold solder joints, just scan with your eyes for solder pads that aren't shiny like the others, might have holes or rings around the leads, or look like they have signs of heat. If you see anything suspicious, you can try wiggling the part or wire to see if you can see the lead moving in the hole. When in doubt, reflow the solder or add a tiny bit to the pad....

 

[Leinhit]

Re: Did Cap Kit, FOCUS POT UPDATE

Ok.. very difficult to get to with board in machine... having some trouble..

But..

R555 is 385
R555 spare is 383

hold on for R556.. very hard