m-45 power meter

Ndirish147

Ndirish147

Member
Hey new to yamaha gear and have a question. I just picked up a m-45, it comes out of protection ok but i have not power meter lights. Bulb? thanks for any help
 
Ndirish147 said:
Hey new to yamaha gear and have a question. I just picked up a m-45, it comes out of protection ok but i have not power meter lights. Bulb? thanks for any help
Click to expand...

Most likely. Is there a switch on the front of the M-45 to shut off meter lights? Its labeled METER ON/OFF.

If the switch doesn't illuminate the subject then you have 2 lamps burnt out. They are 8v/150ma. Contact dgwojo (dave) at dgwojo.com - tell him what you need and he will hook you up.:thmbsp:
 
Last edited:
Have you tried to listen to the amp yet. If it comes out of protection,it should work. Probably be a good idea to check the "idle current (bias) adjustment for both class AB and class A. Especially if it gets real warm in "Normal" mode.
 
Im getting 5Mv on one channel and 25Mv on the other
Click to expand...

5mv what ? Idle ? dc offset ? If that's idle, it will due for now. Class A bias is barely out as tolerance on the low side at 25mv .
 
Last edited:
Oh . OK .. Switch the meter on. You should still have dancing red LED bar graphs.
 
Last edited:
The dancing lights work! The inside is filthy pretty sure it came out of an auto shop based on the way it smells haha. It looks like the wires behind the meters shorted out but its hard to say with all the dirt
 

Attachments

  • IMG_20140222_093032.jpg
    IMG_20140222_093032.jpg
    105.7 KB · Views: 30
  • IMG_20140222_093010.jpg
    IMG_20140222_093010.jpg
    100.4 KB · Views: 27
  • IMG_20140222_093021.jpg
    IMG_20140222_093021.jpg
    84.1 KB · Views: 27
It looks like the wires behind the meters shorted out but its hard to say with all the dirt
Click to expand...

I see that all the time. Its just more airborne particulates deposited to the chassis area that wires were laying close to.
Probably cigarette smoke components.
 
Ndirish147 said:
The dancing lights work! The inside is filthy pretty sure it came out of an auto shop based on the way it smells haha. It looks like the wires behind the meters shorted out but its hard to say with all the dirt
Click to expand...

Need either and air compressor and a soft brush or a vacuum and a soft brush for that filthy mess.:D
 
Thanks for the tip. Going to clean it tonight then give it a good listen. What is the best way to get the case clean? I soaked it in soapy water but it is still has finger prints and spots on it
 
Ndirish147 said:
Thanks for the tip. Going to clean it tonight then give it a good listen. What is the best way to get the case clean? I soaked it in soapy water but it is still has finger prints and spots on it
Click to expand...

I use simple green and windex. If its in real bad shape . I bead blast and powder coat.
 
Ended up trying a magic eraser it worked pretty well actually. I dusted off the inside as best i could for now and put it back together. It sounds excellent much cleaner than the sx-980 with more midrange.
 
Check around on the circuit board around those two larger caps toward the center of the amplifier. Yamaha used SONY bond glue for manufacturing process. This glue ,if present, attracts moisture and oxidizes anything metallic that the glue may be in contact with.
 
I looked for it earlier and didn't see anything, i will check again when I put new lights in. How clean should i get the circuit board?
 
Ndirish147 said:
I looked for it earlier and didn't see anything, i will check again when I put new lights in. How clean should i get the circuit board?
Click to expand...

I don't think I've seen the glue on 45's. But all of the larger amps have it.

I worked on one M-45,like a couple years ago, and thought it strange - no glue-..
 
Last edited:
You must log in or register to reply here.

Similar threads

R
Yamaha m-45 vs m-60
Replies
9
Views
806
Asmodeus2112
Asmodeus2112
mojoe
m-45 rocks
Replies
8
Views
549
mojoe
mojoe
babeba67
M-85 amp with low level hummm...
Replies
3
Views
610
brutal
brutal
M
yamaha m 45 problem
Replies
12
Views
1K
cheltok
C
try1256
M-4 vx M-45 Differences?
Replies
6
Views
683
Susurus
Susurus
Back
Top Bottom