Film Caps - Polarity??

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Hi;
I'm working on my Space Wars and have a Rev.A monitor.
I am replacing the film capacitors and have a concern regarding the polarity. I was under the impression that they were non-polar but when checking the schems, (using Rip Off) they use the
--[ (--- symbol which indicates polarity - no?
BUT the Tant and electrolytic caps have the same symbol but also include a "+" indication as well.
Does this mean that the absence of the "+" indicates non-polar even though the symbol is not
--[ ]-- ??
Thanks in advance
Jeff
 
i'm working on my vectorbeam space war and i think you're right about the caps...if there's no + on the schematic, then it uses a non-polarized cap...hopefully someone else can confirm that for us
 
The first symbol you use is for a capacitor. I don't recognize the second symbol used. A cap is traditionally positive on the straight side and negative on the curved. However, the standards that are commonly used today were not always used on older machines. I think, after looking at the manual, the caps without polarity markings are bi-polar. Even if they are not, bi-polar caps can be used in place of polarized caps.
 
It appears to be that way. I was wondering why they would mark the positive on all the electrolytic and tants and not on the film caps. I was concerned because the film caps I am replacing have a black band on one side, pic attached.

I did not know that a polarized cap can be replaced with a non-polarized cap, very good to know.

Thanks for the help.

Jeff
 

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Oh and BTW, the symbol you did not reconize was supposed to be 2 parallel lines, I could not find those of my keyboard so I used the ones you see.....

Jeff
 
Oh and BTW, the symbol you did not reconize was supposed to be 2 parallel lines, I could not find those of my keyboard so I used the ones you see.....

Jeff


For two parallel lines you could always use lower case 'L' - l l -

Of course, if I saw this I would think 'normally open switch'...
 
For two parallel lines you could always use lower case 'L' - l l -

Of course, if I saw this I would think 'normally open switch'...

Now that I have 3 children running around the house all day, I don't always think straight anymore. That constant "energy" also causes me to make mistakes while troubleshooting causing heartache and hassle!
I only have minutes between "situations" to check e-mail / forums, post messages / responses etc.during the week.
At least I get a couple of hours on the weekends to do serious repairs and play a couple of games....
Jeff
 
i'm working on my vectorbeam space war and i think you're right about the caps...if there's no + on the schematic, then it uses a non-polarized cap...hopefully someone else can confirm that for us

I was hoping that you could help me with a situation regarding a tantalum cap that has no markings on it at all!
I am using a Rip Off schem as I cannot locate one for the Ver A in my Space Wars and it is different than the actual monitor PCB - similar enough to use, but the cap in question is not listed. There is one in the vicinity but not close enough to assume that it is the correct one.
If you could - please check your monitor PCB and please let me know if you have the same one in this location and if so, what is the capacitance, voltage rating as well as polarity.
I attached a picture and if need be, I can send more but I would need your e-mail address.
Thanks in advance
Jeff
 

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On mine, the little blue tantalum cap is a 2.2uf35V cap. Positive side goes to the "right"....as viewed in your picture.

Oh, and film caps are not polorized.
Edward
 
there aren't any markins on your board, like C12 or R23...not sure what chassis you have...mine has all of the components marked
 
On mine, the little blue tantalum cap is a 2.2uf35V cap. Positive side goes to the "right"....as viewed in your picture.

Oh, and film caps are not polorized.
Edward

Edward;
Do you have the exact same PCB as the one in the pic? All the same components in the same locations? Some on my PCB are missing, you can see the holes, as I am in the process of the rebuild but my PCB does not match the Rip Off Schem I am using.
Thanks
Jeff
 
there aren't any markins on your board, like C12 or R23...not sure what chassis you have...mine has all of the components marked

Hi;
No, not one marking. I am using the Rip Off Schem and marking the components I remove with a highlighter, confirming polarity where necessary as well as drawing in the components that are not on the schems. It would be very helpful if I had an actual schematic of the "A" monitor chassis.
Jeff
 
Edward;
Do you have the exact same PCB as the one in the pic? All the same components in the same locations? Some on my PCB are missing, you can see the holes, as I am in the process of the rebuild but my PCB does not match the Rip Off Schem I am using.
Thanks
Jeff
Mine looks like yours...all though, your picture only shows so much :)
Mine has a "normal" looking flyback....as opposed to one of the "box" flybacks.

Edward
 
Thanks to everyone for the help - I fired it up and nothing exploded! - YES!

Now I have another problem, the display is fuzzy and dim, the brightness control has no effect on the display and the spot killer does not work. I can see the game play but not too good.
I have spent some time reviewing the theory of operation as well as the schems and I am leaning towards a defective IC7, any seconds?

Would it be OK for me to work on the game with the neck board unplugged from the CRT?
This would prevent the gun from firing and then I could continue to troubleshoot without the worry of burning the CRT, is this theory correct?

Thanks again for your help with my new project and hopefully I'll be playing Space Wars in the near future - with your help of course!

Jeff
 
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