Yamaha M50 Smoke - Help...

[plresults]

@avionic: Thank you SO much! I got the replacement safety cap in and the M50/C50 is singing wonderfully in my office <pic below>. A few more questions, please:
- I broke the plastic clips that hold the plastic sheet that separates the board in question from the transformer, stripped a screw or two from bottom cover, and need to re-secure the tiny plastic bolt/nut combo. Where might I buy those bits? <pic below>
- is there any special M-50 trick to replacing the bulb or flipping over to LED for the burned out amp power switch light? I've replaced same on an A1
- what is your preferred method to clean up the face place of the amp without damaging same ? It's kind of a fingerprint-y(?) mess in right light.
- as i have the amp opened up are their any preventative maintenance or cleaning steps you like to do? It is a small bit dusty.

Thank you again!
.

 

[avionic]

tiny plastic bolt/nut combo.

Plastic rivet -- reuse them..

 

[avionic]

what is your preferred method to clean up the face place of the amp without damaging same ? It's kind of a fingerprint-y(?) mess in right light.

Magic eraser -warm water with a couple drops of Dawn.. Elbow grease...

 

[plresults]

Plastic rivet -- reuse them..

Reuse the black rivets - okay. What about those two white plastic bits I busted up so well?

 

[avionic]

broke the plastic clips that hold the plastic sheet

Might have some laying around.

 

[avionic]

What about those two white plastic bits I busted up so well?

Might have some laying around.

 

[avionic]

is there any special M-50 trick to replacing the bulb

D-i-s-s-a-s-e-m-b-l-y.....

Easiest to just replace the lamp..

 

[plresults]

Might have some laying around.

Avionic: If you come across two of the white M50 rivets, let me know. I will PM you my address and I can pay you for them of course.

 

[Quake11]

https://www.mouser.com/ProductDetail/Panasonic/ECQ-UBAF224KA?qs=DPoM0jnrROUY3qk3j1JTwg==

avionic:
I have the US model M-50. C607 per manual is 0.22 mfd @ 250V. My installed C607 measured 0.2 mfd @ 125V (?). Marking on cap 104M AC125V ECQ-UC D. I can not find a datesheet on this cap to verfy voltage. Also C611 per manual is 0.068 mfd @ 450 V. Installed read 0.088mfd @ 125V (?). Marking on cap 224M AC125V ECQ-UC D. Again, can't find datasheet.
I take the AC125V as 125 volts ac. I'm thinking these two caps need higher voltage rating. What do you think? My M-50 is dead. First thing found is blown 12a fuse. Replaced with 10a and started checking voltages per manual. No voltage and no lights. I have checked the 3 SCR they are good. I am going to check output trans now. Thanks

 

[avionic]

Marking on cap 104M AC125V ECQ-UC D.

I can not find a datesheet on this cap to verfy voltage.

The voltage is on the cap.. 125V
104 ---> .1µf
M ---> +/- 20% tolerance

Marking on cap 224M AC125V ECQ-UC D

224 ---> .22µf
M -- +/- 20%

I take the AC125V as 125 volts ac. I'm thinking these two caps need higher voltage rating. What do you think?

Look at the M-50 parts list page 11 in the service manual for C607 and 611...

Market code U & C uses the 125v cap
U -- USA
C -- Canada

 

[avionic]

I am going to check output trans now.

That would have been my first step...

 

[Quake11]

I was looking at the schematic diagram for my value of caps and voltage levels and not the parts list. The C611 for UC in the parts list is 0.1 mfd @ 630V ac. The cap value on the schematic 0.068 mfd is for the R,A,G,B. As found per cap reader was 0.088 mfd which is a value near the R,A,G,G machine but with the 125v rating. Looks like per the parts list this should be a metalized mylar 0.1 mfd @ 630V ac. Thanks for pointing out to me the schematic does not show the different built machine component values only the parts list will do this. GOOD LESSON! THANKS!!!!