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nanao sanwa schematics

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Franck 78

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Hi,

Schematics available are not easy to read. Poor repro often but also spaghetti style ;)

I have redrawn the Sanwa PM1745 from a board and one barely usable schematic. My drawing probably have some errors in it and need review.

It is KiCad 5.1 style and is available on github

I did the same for NANAO MS8-29 , only from the board this time. So this one really need some double checking.

I see there is a MS9-29 schematic in four part, acceptable. I think I will do it too.

But the real thing someone ask me to do is the MS2930. No any schematic, lot of components, this one is difficult and I would like some help.
I would like to have the component list done before drawing anything.
I don't have a board to dismantle, and with SMT , a lot of cap will be removed for measuring them.
Volunteers ?


https://github.com/Franck78/SANWA-PM1745
https://github.com/Franck78/NANAO-MS8_29
 
This is incredible work. I have an MS8-29 I'm working on right now and it's already helped me fix a protection fault. Now it has a strange jittery SPC/H Size fault I am trying to hunt down.

I did find these differences on the MS8-29 schematic:

R465 on my board is a 390ohm
VR434 on my board is labeled "34". I assume 30k as it measures 25k.
R442 on my board is a 1.2k
C550 and C551 are 2700nF, not 270nF
C533 on my board is not populated, nor is Q531, R535, Q535, R545, R537
R541 is 27ohm, not 2.7k
C554 on mine is 270nF
 
Hi,
happy this helped you.

R465 so low makes no sense with the 30k pot. Recheck ?

vr434 yes 30K
R442 I have 2K2, need other inputs .....

C533 and others: the purpose of this is adding or not some nanofarad to C532. Strange you don't have that, or C533 is higher ? Or you don't have 15/24 switching?

my C554 is 390n not 330n as I said. But not 270n !

Other values are miss-readings, fixed !
 
Franck 78 said:
Hi,
happy this helped you.

R465 so low makes no sense with the 30k pot. Recheck ?

vr434 yes 30K
R442 I have 2K2, need other inputs .....

C533 and others: the purpose of this is adding or not some nanofarad to C532. Strange you don't have that, or C533 is higher ? Or you don't have 15/24 switching?

my C554 is 390n not 330n as I said. But not 270n !

Other values are miss-readings, fixed !
Click to expand...

R465 is orange white brown and measures 390 out of circuit.

My chassis does switch 15/24 by moving the jumper. C532 is 8.2nF same as listed. Not sure why this whole circuit is missing on mine but seems to be connected to H Phase which is working fine.

Oh yes, also. C446 on the schematic is listed as 4.7uF NP. On my chassis and on all the other cap lists online, it is 33uF NP.
C447 also should be 47uF
 
Last edited:
Thank you for the Pm1745 schematics 😭. Got 4 of these fuckers, almost gave up on the repairs.
 
If your attampting to redraw the schematic for a ms 2930, Please let me know what you need as i would love to help out anyway i can. This would be a great piece of info to finally have so that these chassis could be alot easier to repair.

Tony
 
Hi Tony,

I loose a lot lot lot of time with creating each component. Finding the value, typing the name etc etc. Even with a bad schematic, it is very time consuming.
For the MS2930 I would like to do it as follow
-some hires photos (done)
-divide in zones (done by nanao)
-create a ggogle shared spreadsheet
-inventory each smd in each zone
-build from that list a KiCAd schematic, just components, no connection of course

so that when i see R134, I search R134 on the unused partlist and just move it to (real) schematic
 
I can't offer an MS-2930, but I can offer a Toshiba PF PB9929. It has had some components robbed from it and the neck board is cracked in half, but it's yours for free if you want to try making a schematic for it.
 
Thanks Franck!. Used your schematics for a MS8-25 color issue I had: https://www.arcade-projects.com/thr...leed-flicker-fixed-cap-list.34481/post-474207

Found 2 differences in the neckboard (could be more) that I'm not sure if they are because it's a MS8-25 but here they are in case it's useful for somebody since they are very similar or in case you decide to do a diagram for it:
  • Zeners ZD301 / ZD321 / ZD331 are 15v, not 7v5
  • D303 / D313 / D323 are not present
 
ok



As I said somewhere, creating the component is what take a lot of time and I want to try to start from a prefilled Schematics with most of the components 'ready' to place. I need some help.

I want to do the Sanwa 29E31S
the schematic is more or less unreadeable
the part list is usable

If this is conclusive, we will try from the photos of Nanao 29E30 pcb to get the partlist, then the schematics...

Here is a google doc to fill from the pdf partlist of the 29E31S:

https://drive.google.com/drive/folders/1p_50uXDrTSEtWru4vT13TatysSq76L31?usp=drive_link

While it is filled up, I will write a macro to create a KiCad file, each line adding a component.
 
Oh that is good. The bad thing is this schematics does not come up with duckduckgo (or google unsure) or on thread like this exists ;)

https://www.ukvac.com/forum/threads/sanwa-29e31s-clear-schematic-needed.74102/page-2



The idea here seems to be that if C471
charges to more than 25V or so, D480 will
start conducting until H deflection stops,
in turn switching the flyback driver off
and keeping it off. Redundancy/protection
in case the normal feedback path fails,
maybe?

I call that XRay protection. If too much output on pin 10 of the tht (thus also to much HV) , thyristor is turned on.

Now will the thyristor turn off if H-sync keeps coming ? Nothing stops the LA7856 ! The thyristor is here to memorize the default until the chassis is powered off.
 
I found these errors on the schematics.

C911 listed as 24µ, is a 47µ

The representation of Q412 is not accurate (regarding the level of details elsewhere). The 2SC5143 have a damper diode and a base resistor built-in.

The PDF, some component respond to CTRL-F , some not (R499 found, , R408 not found).


I'm fixing a board. Trying at least. I have no H-Sense signal. C4A7 is charged to 3V8. Through R498 R4B2. The thyristor (D480) is off. When I turn it on with a 1K resistor between A,K, it stays on most of the time.
 
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