Sanyo 20-DZC (Monitor in a box) Questions

CamaroMurph

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I am working to complete the restoration of my Nintendo Helifire. I am working on the monitor which is why we are here today.....

It is a Sanyo 20-DZC monitor in a box which is the predicessor to the 20 EZ. All I have for the schematics are a very blurry version found in the Radarscope schematic set. For those of you that will tell me it is the same as the 14" version it is similar but not the same. I can tell that from the schematics for both which I compared. I have also been comparing it to the later EZ version to help answer a bunch of questions. So, after all that, I will outline the remaining question as this thread moves along.

Question 1. The C606 Cap in the monitor currently is a 680uF - 160V. Main B+ Filter Cap I think. All the scheamtics, 20-DZC, 14-APL, 20-EZ... show it as a 470uF - 160V. I checked the CAP in both my DK and Radarscope which are 20-EZ's and they are 470. Which do you think is correct?

Some pictures of the chassis can be seen in my restoration thread here. Picture #2 has the CAP on the far left of the picture. It is very hard to tell if that CAP has ever been replaced. You can see a preview of some of the other questions in the restoration thread.


http://forums.arcade-museum.com/showthread.php?t=127642&page=5

More question to come.
Murph
 
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OK. I spent afternoon with the blurry schematics of the 20-DZC and the 14-AZL and there are only two cap differences. Most importantly there are schematic differences certainly in the horizontal output section. My monitor is closer by the schematic to the 14-AZL than the 20-DZC. Not sure if there was a previous version of the 20-DZC but for now I will go with the 14-AZL schematic.

Now, two of the problems I have are not related to which schematic. One is that it looks like someone has made some changes to the horizontal output circuit. Could it be that changes are necessary to use the 14-AZL chassis in a 20" montor. That is all for now.

Enjoying a bit of the drink tonight so help me out here. I would like to keep the monitor in a box to keep this original but I need to have it function properly.

Murph
 
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Question 1. The C606 Cap in the monitor currently is a 680uF - 160V. Main B+ Filter Cap I think. All the scheamtics, 20-DZC, 14-APL, 20-EZ... show it as a 470uF - 160V. I checked the CAP in both my DK and Radarscope which are 20-EZ's and they are 470. Which do you think is correct?

In this circuit, it does not matter. It's the B+ filter. The larger cap would probably do a slightly better job, but it makes no real difference.

When working on devices where the component values differ from the schematics, I usually just stick with what's currently there unless I have good reason to change it. It's pretty common for schematic/device discrepancies, and you know that the monitor worked at some point in it's life, in the configuration that it is in now, so just keep it that way and don't try to make the monitor match the schematic. There might be a reason for it.

-Ian
 
Thanks for the insite. I am leaning toward just replacing caps with what's in there. There are still a couple of items that bother me.

I did not see a ferrite core in the horizontal width coil. There are also extra caps that are in that leg of the circuit. I wonder if they were adding/subtacting caps to change horizontal with since there is no ferrite core in the coil?

Murph
 
I did not see a ferrite core in the horizontal width coil. There are also extra caps that are in that leg of the circuit. I wonder if they were adding/subtacting caps to change horizontal with since there is no ferrite core in the coil?

Perhaps. Maybe. Hard to say without seeing it. Do you have a picture?

More to the point... what is actually wrong with the monitor? Does it work at all? Have foldover? Is the horizontal width currently correct?

-Ian
 
Hard to say what's wrong with it if anything. I bought this game from a bulk buy and of unknown origin (working or not). It did not have a plug on the cord so the first thing I did was inspect the inside of the game, looked good, put a plug on the end of the cord and turned it on. Much to my happiness, it worked. I coined it up and played a game without noticing anything at first. (short game as I never played before) I played a second game and the monitor started breathing. Size going in and out about and inch or so. I turned it off immediatly as I didn't want anything serious to happen. This game probably sat for many years before I got it.

That was 2 years ago or so. I started working on the restoration of the cabinet about 1 year ago and am now just getting to the monitor before I put it back in. Since I needed to pull the chassis to give it a good cleaning and the screen was "breathing" the last time I had it on I figured I would do a cap job while it was out. There were a couple of caps that I couldn't read the spec's on because they were in bad spots so that's when I got the schematics out and started noticing the differences. That's where this thread started.

I suppose the best thing to do at this point is to cap it just as it was and try it. If it works then great. I was just trying to see if there was anthing that anyone would notice that might prevent me from having to pull it out again after I try it because something obvious was wrong.

(Thanks for responding. I do appriciate the fact that someone is)

Murph
 
One other thing for documentation purposes. After digging deaper into the schematics, I can't say which schematic my monitor resembles more. In one part of the circuit, it matches the 14-AZL schematic and another part of the circuit it matches the 20-DZC circuit. Each of these sections are unique to the different model. So I'll just call it ODD.

Murph
 
Ian -

Thanks for all the words of wisdom. I completed the cap kit replaced everything just like it was. I think it turned out great. Ran it for about 7 hours today without issue.

Murph

PS - Lot's more pic's of the monitor in my Helifire restoration thread.
 

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That thing is looking nice (I was just at your other thread).

Nintendo used so many oddball Sanyo monitors in their early days. Everytime I think I've seen them all, another one pops up. I used to have a Radarscope cabinet with the TV-in-a-box style monitor. I just checked my notes.....it was a 20-YZL. My "box" looked different than yours (sorry, I have no pictures). And my cap locations didn't match the ones you were asking about a couple posts ago. Here's my list...

Sanyo 20-YZL 19"
TV-IN-A-BOX

1uf50V C166/C302/C453/C454
1uf160V C408/C467/C610
4.7uf25V C162/C411 Both BP Caps
10uf50V C301/C303/C406
10uf160V C407/C471
22uf50V C464
47uf10V C458
100uf16V C459
100uf160V C410/C472
220uf16V C161/C202
220uf25V C469
330uf25V C468
470uf10V C609
470uf160V C606 B+ Filter Cap

Audio Board​
1uf50V C375
4.7uf25V C371 BP Cap
10uf160V C377
220uf25V C378

Edward




 
Thanks Edward.

Do you have a schematic of the 20-YZL you could share? I would like to compare it to my monitor and see if it is closer than the 14-AZL or 20-DZC schematic.

It seems to me I have seen a picture of the Radarscope monitor in a box and it was shaped differently than the Helifire one I have. I wonder if it had more to do with the shape of the cabinet than the game. Maybe the slant sided game had a different monitor angle (lay back) than the more traditional faced cabinet.

Murph
 
I'll check for a schematic when I get in the shop tomorrow. I don't think I could find one. Luckily, my beast only had bad fold-over (and it look as if it had never been worked on).....a cap kit later, and it was good. It did not have any of the weird cap/jumpering stuff you talked of several posts prior.

Edward
 
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