Dissecting Nanao MS8-26SU Chassis

SterlingRush

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Some of you may already be aware, I have been on a mission to tear one of these chassis apart, to have more accurate information about them. I am almost finished with removing and documenting, just about every dang piece on one of these chassis. I am down to just the tiny resistors and diodes, and would like to ask for some assistance. If there is a member here, that is a diode guru, and would like to help me finish documenting these, I would appreciate it. Even if it's pointing me in the direction I need to go, to educate myself more regarding these tiny little bastards, I'll take it.

For the record, this chassis has about 40% lifted/removed pads, and some other damage. I felt this was a great candidate for dissecting and documenting.

Pics previous to my latest stopping point, connectors/poly & disc caps/misc removed, waiting to document these tiny diodes and resistors:


CIMG4020_zpsaab56f6f.jpg



CIMG4022_zpsd6be0014.jpg
 
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Making progress, have roughly 50-60 resistors to still document, but it's getting there. And in the end, will help rewrite the schems for this chassis.
 
WARNING!!!! The images below are NSFW, do NOT view this on a work computer.


Are you guys ready for some nakedness? Isn't she pretty? Yep, she's a little dirty, but we like that.......... :)


Bare Main PCB:

CIMG4039_zpsdbff5c6f.jpg



Neck Board PCB:

CIMG4038_zps99a1c329.jpg



And 15 pages of documentation(my Holy Grail at the moment, yep, used the word "grail"), parts listing and positions, with a couple of detailed notes. Also, I found two items populated on the board, that's not even on the schematic. Verified these parts, with two other chassis, from completely different ends of the US.

CIMG4042_zpsbc755782.jpg



And these little bastards(diode and resistor tied) were fun to document, there's three of them on the neck board:

CIMG4034_zps70b2da26.jpg
 
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Slowly and surely, bits and pieces are getting done :)


Cap Map now available for the Nanao MS8-26SU.

Cap locations marked in red, are typically found in the pre-made cap kits, cap locations in orange are typically not included in pre-made cap kits.


CapMapMS8_26SUFinal_zpsa9f9cddd.jpg




Cap Listing:
C332 / 10uf 250v / located on neck board
C401 / 1uf 50v
C420 / 1uf 50v / located on IC board IC103
C422 / 470uf 50v
C431 / 33uf 100v
C432 / 33uf 100v
C433 / 10uf 25v / 10uf 100v was installed on the chassis
C437 / 120uf 50v / not included in most cap kits
C451 / 100uf 50v
C452 / 1uf 100v
C454 / 47uf 50v
C501 / 1uf 50v
C521 / 33uf 16v
C522 / 47uf 16v
C532 / 1uf 50v / located on IC board IC103
C537 / 4.7uf 100v
C561 / 10uf 100v
C563 / 1uf 50v
C570 / 22uf 160v
C572 / 47uf 16v
C573 / 470uf 16v
C574 / 10uf 50v
C576 / 470uf 16v
C579 / 1uf 50v
C905 / 680uf 200v / not included in most cap kits
C906 / 100uf 200v
C908 / 47uf 25v
C909 / 22uf 160v
C910 / 220uf 50v
C912 / 220uf 35v
C913 / 220uf 35v
 
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Nice work documenting this chassis. There is basically NO info on these monitors.

I was working on a Manx TT that has 2 MS9-29A monitors and the only thing I could find was a cap list. Bob Roberts carries a cap kit for my chassis but the kit was missing some of the bigger caps.

I also noted that one of the caps (C411 2.2 uF 50v) is non-polarized on the chassis but a regular electrolytic was supplied with the kit.

Again - real nice work on this.
 
Awesome job man, I need to fix two of these so hopefully we can document all the trouble spots too. The burn marks in your photo are revealing, thinking I should double check stuff in those dark areas to try and bullet proof the chasis.
 
That burned area towards the middle of the chassis, I have seen the pads and traces in that area, being prone to lifting or destruction. Use caution when handling that part of the chassis, the constant heat weakens that area, and the weight of the heat sinks likes to push around the pads underneath. It starts with the pads for the heat sinks, and likes to start tearing away from there. I've got a few different pics in other threads, I'll bring them into this one, when I'm not on an IPad.
 
Bringing these pics in, from another thread I posted in, trying to centralize more of the info for the MS8-26SU. Below, show differences from a MS8-26A chassis, to a MS8-26SU chassis.


I've noted the chassis, to show the differences by a visual inspection.

MS8-26SU:

MS8-26A-SU_zps18680823.jpg




MS8-26A:

Nanao26A-01_zps11d20ba1.jpg



Nanao26A-02_zps0930c1ac.jpg
 
Could you please post the values for the following resistors?

R432
R434
R435
R445

Mine are burnt and cracking, thanks.
 
Thanks to your info here is my VF1! Thanks man!
 

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Just wanted to send another thanks your way SterlingRush. I fixed my other Nanao monitor that had the same issue. It is totally worth it to change out most resistors and the cap in the center of the chasis. Discolored resistors have seen better days. Thanks again and let us know where you post the rest of the info you have if you decide to make it all public.
 
Thank you akumojo, happy to help, I know how much of a pain these chassis are with the limited info available.

I still have quite a bit of work on my side, I'm currently writing up the listing of part locations/part descriptions ect.... I've found a couple items already, that were not on the original schematic, but existed on the chassis. Then had to draw them onto the schematic. So after seeing that, I am going through and double checking the schematic, while writing up the documentation. Nice long process :)
 
Placing this here, as I'm tired of always having to search for it :)

Testing B+ circuit(monitor powered off):
Monitor powered off, pull the F902 fuse out, test resistance between the fuse clip closest to the tube, and TP2(just in front of and a little to the side of the fuse clip you're testing). Should get resistance between 2k to 5k Ohms, meaning the circuit is fine. If any reading different than that, check D533(towards front edge, middle of board)(Diode 1SS244).

To check/set B+(Monitor powered on):
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
 
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So I have a couple of these...and would like to thank you very much for the work put in.

I also have more than a few ms9-29su's...and could offer one up later, if you decide to jump in on another nanao monitor breakdown. :D
 
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