Help ID this nanao chassis

drowtales

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See photo below.
It's - not - a MS8-26SU This chassis has a c560 . Brought the cap kit from Ian kellog and i didn't think of comparing the caps value first. The UF values were different. Its only when i came to the missing cap that i realized the problem.
So i thought it's the ms8-26SG. That one has the missing c560. But no, there's caps that were never installed on the factory side. For exemple : C438 . While it is there on the board, it's just a wire on the parts side.
Pre-cap, this chassis worked, now it's in shut down mode with only 50v on the b+ transistor transistor so somewhere there's a cap(or many) that are the wrong type. Please help identify it so i can find proper cap.
 

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it looks like the SG and just because the SG cap kit has a C438 and your board doesn't it still could be a variation of it. there is a bunch of variations with different letters at the end i build mainly for europe, i don't recall even selling the SG or the other variations in the usa mostly europe and canada.
 
looks like a MS8-26A-SU.

I really don't like the nanao's. There are so many variants that its nearly impossible to keep track of. I'm still learning all of them and what's unique.
 
looks like a MS8-26A-SU.

I really don't like the nanao's. There are so many variants that its nearly impossible to keep track of. I'm still learning all of them and what's unique.

Couldn't find a ms8-26a cap list anywhere to compare , only people asking for it. Does anyone have the cap list for the A model?
 
Dang internet, this will be the third time I write this up, probably the short hand version, of the novel I wrote twice already :)

From what I can see in your pics, you have a MS8-26SU chassis, not a 26A. There are easy differences to spot, between the 26A and 26SU chassis. See page 2 of my thread here:
http://forums.arcade-museum.com/showthread.php?t=332652

With that said, C560 should have a 104K(0.1uf) small brown rectangle cap populated, and is not replaced with your normal cap kits. Generally there's no reason to. This location should not have a radial cap populated. If it did, I'll ask what you have/had populated in C561? It should be a 10uf 100v. Check and see if these two positions are swapped for some reason? C561 is diagonal across the PCB, tucked about 1/2" behind the little upright circuit board IC103. C560 is silk screened like it's supposed to have a radial cap, but one should not be placed there.

You mentioned other cap values were off, which locations? What was the previous cap value vs the new cap kit? So far from your pic, that is the only thing I see out of place(C560 having a radial cap), without knowing cap values you currently have installed.

BTW, your HOT looks roached, might think about replacing that, I see corrosion on it.

Use this method to check your B+


Now, to check B+:
Monitor powered off, disconnect your video signal from the game PCB. Power on the monitor with no video signal, put your red meter lead on TP1, and black meter lead on TP2(ground), you should be getting +92DC volts. Both test points are just in front of the 2A fuse, look for three little posts in a line(TP1, TP2, TP3). Due to location, this feat is easier to do, using alligator clips connected to your test leads.


CIMG4244_zpstzx15ard.jpg


CIMG4242_zpsurl0og7s.jpg
 
Well then, the internet strike back with new info for you Sterlingrush.
C560 was not a small ceramic cap. It was a radial capacitor; 47uf 160v to be exact. The same as the SG model, and why i believed this board to be it.
the voltage at the tp1/tp2 checkpoint you suggested is 82. 10 volt less than it should.

If i could recall where all the caps went, this thread would not exist, however here is the one proof i have that the value of UF are different. I hold a 330 uf 16v that was taken from the board... Which , again, point out to the SG model with it's C521. There is no 330 UF cap in the SU cap kit!

Your link and photos does show it is not an A model however.
I see what Ian meant by "There are so many variants that its nearly impossible to keep track of"
 
Not willing to call it a 26SG just yet, as I have pics of what an untouched 26SG is supposed to look like, tags and all. According to that information, the chassis is setup more like the 26A version. If I am wrong, please someone correct me, but that is what I have found with my research. I would like to know where you are gathering your information regarding the 26SG? I only ask as I would like to view it, to see what you are seeing.

I will say, I did go through my stack of Nanao MS8-26SU chassis. Low and behold, I do have one chassis similar to how you are describing yours, unmolested, untouched. Again, I won't call it a 26SG chassis, until we can truly determine what sets the chassis apart from each other. I will call it a 26SU variation for now. Not that I'm disagreeing with you, but for future searches and info for others, lets make sure we are not just randomly naming chassis models, until we know 100%

Anyway, my one chassis did have a 0.22uf radial cap at C560, instead of the 104K(0.1uf) ceramic cap. Same chassis also had the 330uf 16v cap at C521. My other 5 chassis, had the 104K(0.1uf) ceramic cap at C560, and 33uf 16v at C521.

If you have a 47uf 160v cap installed at C560, that will cause you some issues. C908 close to C560, is what should have a 47uf 160v cap.

Side by side comparison, there are only three cap differences between the 26SU and this variation chassis.


Cap list as follows:

-C401 / 1uf 50v
-C420 / 1uf 50v
-C422 / 470uf 16v
-C431 / 33uf 100v
-C432 / 33uf 100v
-C433 / 10uf 25v
-C437 / 120uf 50v
-C438 / Jumper
-C451 / 100uf 50v
-C452 / 1uf 50v
-C454 / 47uf 16v
-C501 / 1uf 50v
-C521 / 330uf 16v (33uf 16v installed on 26SU)
-C522 / 47uf 16v
-C532 / 1uf 50v
-C537 / 4.7uf 100v
-C560 / 0.22uf 160v
-C561 / 22uf 100v (10uf 100v installed on 26SU)
-C563 / 1uf 50v
-C570 / 22uf 160v
-C571 / Not Populated
-C572 / 47uf 16v
-C573 / 470uf 16v
-C574 / 10uf 50v
-C576 / 470uf 16v
-C579 / 1uf 50v
-C905 / 680uf 200v
-C906 / 100uf 160v
-C908 / 47uf 16v
-C909 / 22uf 160v
-C910 / 220uf 50v
-C911 / Jumper
-C912 / 220uf 16v
-C913 / 220uf 16v



Position C560 on MS8-26SU, 104K(0.1uf) ceramic cap:

CIMG4386_zps49mobllo.jpg





Position C560 on MS8-26SU variation, 0.22uf radial cap:

CIMG4385_zpsuxqodqdv.jpg
 
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Thank you very much for the list Sterling and for compiling infos on these nanaos.
I did not see sign that the board was reworked so i must believe the c560 47uf 160v was original. The fact the board was working is another sign that it was the correct cap.
Based on the list, my second recap to make it SG led to two mismatching cap. C909 and c437. I've proceed to restoring the two caps from kit...

Result is : Nothing. Actually lost 1 volt on the b+ down to 81
Either this board is yet another variation of SU or something fried when the wrong caps were put in. If it were the hot, the fuse(s) would blow. If it were a WG, i'd remove d10 to check the voltage regulator but there's no informations out there on something similar for nanao
At this point changing the yoke and giving up on the chassis is the only path left. :(
 
Did you happen to have a 0.22uf cap that was pulled? Just curious. If so, place that and the 47uf where I have listed above, and see if that changes your readings. I dug through some of my old responses in other threads, mainly for how to check your B+ circuit for other issues.

Last post on page 2, tells how to check that circuit with power off, no video signal.
http://forums.arcade-museum.com/showthread.php?t=332652


It's possible you may need to adjust the B+ pot, I'm still a little surprised it's reading that low. I wouldn't look at the yoke yet, I think that's farther away from what is actually causing your issue. Could be a lifted pad/trace, as these PCBs love to do that, lol.
 
I,ve done a dozen chassis this summer but i doubt i'd find that cap among them. I did a quick search if it could be found on kortek(2001 and another model that mimick the k7000), wells(4900&k7000) and g07,. Nothing. And since the nanao board i had came with 46UF, i don't have access to a 0.22. I've checked ebay ; no luck, only specialized cap with that type of UF value. (Correcting : AND voltage)

Now for the test! It is out of value, i get 6.09 , way above the 2-5k range at every test.
Diode D533 in circuit test: 670 on continuity check one way, nothing on the other way. I can't tell which side is negative, that thing is tiny! But that one side does not let the power through seem to be a good sign.

You mention the B+ adjustement. I've removed the glue the operator put on r910 and spun the pot, while the multimeter was connected. At best i'd get a fraction of a volt difference!
 
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a 0.22uf isn't that uncommon. i stock it for several cap kits i build. i would think digikey or mouser would have it.
 
Not willing to call it a 26SG just yet, as I have pics of what an untouched 26SG is supposed to look like, tags and all.

I think the final lettering doesn't identify chassis version and it may refer to something else (region of marketing? Frame style?)

Here are three examples of monitors labelled MS8-26SG and they don't have the same chassis. The first one has the main chassis layout with B+ fuse parallel to the PCB edge:

http://forum.hfsplay.fr/galerie/xin...-20.html?sid=b3aa9370985676e04486c992214ddbea

The other two have the chassis layout with B+ fuse slanted:

http://forums.arcade-museum.com/showthread.php?t=295290

http://forum.arcadeotaku.com/viewtopic.php?f=4&t=32919&p=447027

The chassis in the first link is identical to the OP's chassis (same PCB numbering, electrolytic on C560). Then again the same PCB is also used for what is called MS8-26SU (the only difference seems to be the polypropylene cap on C560). This PCB layout (no matter if it's called SG or SU has always bridges on C438 and C911).

Note that there is also a MS8-26SE which has the PCB layout with slanted fuse like the MS8-26SG in the second and third links but also like the version called MS8-26A:

http://imgur.com/a/UIX7a

To me all these letterings are misleading as far as chassis identification is concerned.
 
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