K7500 Cap Kit Map

friedfish

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Does anyone have a map or layout for a K7500 chassis? I ordered a cap kit from Bob Roberts, and while installing the caps, I noticed the chassis is labeled with two C731.

In addition, I cannot find all of the caps listed on the sheet provided on the cap kit sheet. The cap kit sheet also references a cap that is labeled as 10 uf 50V NP. What does the NP mean as that spot on the chassis appeared to have never had a cap.
 
NP = non-polar......also called bi-polar....basically, there isn't a "negative" side or a "positive" side. Both legs are the same.

Edward
 
Also, there was a 7501 and a 7502. If I recall, there is a slight difference in capping the two. Also, while I think I recall seeing two labeled C731, one side of the chassis says that while the other side does not, so check the other side.

Anyway, here is the list for a 7501, made by pulling each cap:


Neckboard
C501 - 10uF 25v
C502 - 10uF 25v
C503 - 10uF 25v
C504 - 4.7uF 200v (105)
C507 - 100uF 16v
C530 - 10uF 25v

Main Chassis
C105 - 270uF 400v (filter)
C107 - 33uF 200v (105)
C115 - 100uF 200v (105)
C117 - 22uF 63v
C126 - 1uF 50v (105)
C127 - 470uF 35v (105)
C304 - 1000uF 25v
C305 - 2200uF 35v (105)
C310 - 10uF 200v (105)
C600 - 47uF 16v
C602 - 10uF 25v
C605 - 100uF 50v (105)
C607 - 470uF 35v
C610 - 2.2uF 50v (105)
C613 - 100uF 50v (105)
C615 - 3.3uF 16v
C616 - 1500uF 35v (105)
C700 - 220uF 16v
C701 - 10uF 25v
C706 - 1uF 50v
C709 - 1uF 50v
C712 - 1000uF 16v
C713 - 4.7uF 25v
C716 - 1uF 200v (105)
C730 - 4.7uF 25v
C731 - 10uF 25v
C732 - 10uF 25v
C734 - 330uF 63v (105)
C805 - 2.2uF 200v (105)
C808 - 2.2uF 200v (105)
C811 - 4.7uF 100v NP (105)
C812 - 2.2uF 350v

HOT - C3688
Flyback - OW053X067-1001

"105" means high-temp
"NP" means non-polarized
 
Also, there was a 7501 and a 7502. If I recall, there is a slight difference in capping the two. Also, while I think I recall seeing two labeled C731, one side of the chassis says that while the other side does not, so check the other side.

Anyway, here is the list for a 7501, made by pulling each cap:


Neckboard
C501 - 10uF 25v
C502 - 10uF 25v
C503 - 10uF 25v
C504 - 4.7uF 200v (105)
C507 - 100uF 16v
C530 - 10uF 25v

Main Chassis
C105 - 270uF 400v (filter)
C107 - 33uF 200v (105)
C115 - 100uF 200v (105)
C117 - 22uF 63v
C126 - 1uF 50v (105)
C127 - 470uF 35v (105)
C304 - 1000uF 25v
C305 - 2200uF 35v (105)
C310 - 10uF 200v (105)
C600 - 47uF 16v
C602 - 10uF 25v
C605 - 100uF 50v (105)
C607 - 470uF 35v
C610 - 2.2uF 50v (105)
C613 - 100uF 50v (105)
C615 - 3.3uF 16v
C616 - 1500uF 35v (105)
C700 - 220uF 16v
C701 - 10uF 25v
C706 - 1uF 50v
C709 - 1uF 50v
C712 - 1000uF 16v
C713 - 4.7uF 25v
C716 - 1uF 200v (105)
C730 - 4.7uF 25v
C731 - 10uF 25v
C732 - 10uF 25v
C734 - 330uF 63v (105)
C805 - 2.2uF 200v (105)
C808 - 2.2uF 200v (105)
C811 - 4.7uF 100v NP (105)
C812 - 2.2uF 350v

HOT - C3688
Flyback - OW053X067-1001

"105" means high-temp
"NP" means non-polarized

Modessitt, thanks for the list on the 7501, I have to do 2 soon.
 
I've done a couple of these, they're really a lot of fun. just make sure you don't bridge any solder points (particularly to that one transistor that controls width... yours might be mounted at the back of the frame with a jumper wire with a red plug too, make note of how that goes on if so)

and don't be weirded out if the caps you pull out are of completely different values.

I like drawing my own cap maps before I do monitors, even though a couple of the ones I had were readily available online. :)

just draw a rectangle, and draw boxes of where major components and just fill in all the caps around them. print out mod's cap list, and place a dot in front of each one that you've located.

I personally don't solder each individual cap, cause I've had instances where there was a cap listed with 2 different voltage values and I picked the cap that was supposed to specifically go to another location, and had to take the cap back out. I just fold the legs flat, then solder them all at the end.

you MIGHT run into lifting solder pads, so don't cut the legs off the caps yet. if a solder pad comes up, run the legs in a criss-cross pattern to pull them tight against the board (so as to hold the solder pad against the board) and solder them like that, then cut the wire. otherwise in other cases (U5000s and K7500s alike) I've had to scrape the traces and solder direct that way, or to the next point in the circuit path. of course if you go this "jumper" route, make sure the cap leg follows the same path as the original trace.

it won't be as pretty, but at least it will work. get out your meter and do continuity checks if you're uncertain.

take your time and good luck.
 
Thanks for the responses. I think I may have had a solder pad come undone on the negative side of C613. I haven't tried the chassis out yet, put the solder pad was only hanging by a small portion. If I want to run a wire versus scraping down the board, where would I run the wire to from C613?

I have not seen a manual anywhere in the usual places that would show me where the circuit runs. How do I tell which chassis it is, 7501 or 7502? The board is only labeled as P793, 025A1471-001, and then 85X0410-001C in the middle.
 
On the back left corner you should see a white sticker with a number that says WGM2575-etc. (or 2775 if it's a 27"). The number below it typically will have 7501 or 7502 in it somewhere.

The yokes are also different, I think. I saw a 7501 that had the rings and the yoke as one piece, and a 7502 that had them separate. I've also seen about four different numbers for the yoke...
 
I tried the monitor chassis and the chassis still works, but the problem I was having before the cap kit still persists. The screen is not filled vertically and I have about 3 inches of black on both the bottom and top of the screen. The remote board vertical size knob does cause the screen to change size, so it does not appear to be a remote board issue.

Does anybody have any ideas where I should look to resolve this problem?
 
I don't know about vertically. the pots do tend to break on these though, maybe you have a bad V-size one? that's weird. I had a K7500 that was in very bad condition, jailbars and artifacting in the middle and all, and all of that was fixed with a capkit.

I even messed up and installed a cap backwards, and it was still fine. (incredibly STUPID move on my part, good thing it wasn't a major one)
 
there is a transistor that is sometimes mounted on the back right corner of the frame that has a connector going to it. If the connector is on backwards, it will affect the picture size and won't adjust out properly - although it normally affects the horizontal, not the vertical...
 
For the cap value listed for C616 provided by modessitt, the uf value does not match with the list that came as part of the cap kit from Bob Roberts. Modessitt lists the C616 uf value as 1500 uf but Bob has it listed as 2200 uf. What could happen if the incorrect uf valued cap is installed? The manual for the K7500 show a 1500 uf value for C616, but I do not have any 1500 uf caps.
 
For the cap value listed for C616 provided by modessitt, the uf value does not match with the list that came as part of the cap kit from Bob Roberts. Modessitt lists the C616 uf value as 1500 uf but Bob has it listed as 2200 uf. What could happen if the incorrect uf valued cap is installed? The manual for the K7500 show a 1500 uf value for C616, but I do not have any 1500 uf caps.

I think Bob gets his caps from Mouser. Mouser stopped stocking that value. Any cap value Bob doesn't have....he always rounds up to the next size. Is this good or bad?..I don't know. I noticed the manual also calls for it to be a 105° cap. It's in the vertical deflection circuit. Digi-Key still stocks it...in several varities.

Edward
 
For the cap value listed for C616 provided by modessitt, the uf value does not match with the list that came as part of the cap kit from Bob Roberts. Modessitt lists the C616 uf value as 1500 uf but Bob has it listed as 2200 uf. What could happen if the incorrect uf valued cap is installed? The manual for the K7500 show a 1500 uf value for C616, but I do not have any 1500 uf caps.

It is a filter cap and is fine to use the 2200uF.

Well, it's not THE filter cap, but a 2200 works just fine as a replacement....
 
I give up on this monitor. The problem has been the picture does not vertically fill the screen. So far I have:

1. Done a cap kit;
2. Tested U601 Pin 9 for 25 volts which it has;
3. Replaced U601;
4. Switched out the vertical size knob on the remote board.

None of these have made a difference. Does anybody have any other suggestions?
 
Check the value of R618 and R303 to make sure they are okay. Check C616, C613, and C610 for proper size and polarity, as well as good solder traces. Check Q602...
 
I am trying to check the value of R618 and have been unable to find it on the chassis or on the schematic I have which is somewhat blurry. Can anyone point to the area where R618 is located?
 
See the location of R618 below.

However, I recently fixed a vertical deflection issue on one of these. The problem was D302 was shorted and R303 was open. Check both. If D302 is shorted and you only replace R303, then R303 will smoke again.

As for R618...

7500-R618.png
 
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