Issue with SA-7800

[petehall347]

d27 is a diode on the other side of the board .. d means diode ...

 

[Ryan Walton]

d27 is a diode on the other side of the board .. d means diode ...

Okay well its still marked with "27" right? I get 0.00 either way....i Mean one end is sticking out the bottom (that I showed you a pic of) and I also measure 27 on the other side (same component right?) and still got 0.00

 

[Ryan Walton]

is fu2 the black wire that is connected to d27 in that pic I showed?

 

[petehall347]

fu2 .is fuse number 2 .
just been looking at the pics again and see the fuse holders look like they have been getting hot where they enter the board . clean the fuses and holders .

 

[Ryan Walton]

fu2 .is fuse number 2 .
just been looking at the pics again and see the fuse holders look like they have been getting hot where they enter the board . clean the fuses and holders .

I just saw that in the service manual Pete.... can I ask you... are these 3 fuses are they all 8 amp or what should my reading be? Maybe I haven't checked them correctly?

 

[Ryan Walton]

nm...i see .8amp, .8amp and 6 amp, right?

 

[petehall347]

crash course on some component id codes .
R resistor
D diode
T .TR .Q transistor . not strictly true but most have 3 legs .
C capacitor .
L coil or inductor ..
SW switch ..

 

[petehall347]

fu1 6 amp
fu2 fu3 0.8 amp . 800 milliamps .

 

[Ryan Walton]

Okay so.... can you tell me the correct way to measure the fuses? I thought I was doing this right but maybe not? I have red & black on each side and set to the "continuity" setting on the MM.... well on the 6amp I get a "1" reading and on the .8amp I get .01 on both???

 

[petehall347]

they look ok . now try fuse holder to fuse holder with fuse installed . this checks to be sure the fuse is connecting to the holder .

 

[Ryan Walton]

they look ok . now try fuse holder to fuse holder with fuse installed . this checks to be sure the fuse is connecting to the holder .

would I keep this in the continuity setting?

 

[petehall347]

yes of course .
it can however be done with power on and measuring volts . and actually a better way to test . but ups the odds of something going wrong .

 

[Ryan Walton]

if so... when measuring the holders i get various readings... it just keeps jumping around to different ones

 

[Ryan Walton]

Also... what do you use to clean these components? I ordered some "deoxit" because I had heard it was good stuff... good idea?

 

[Ryan Walton]

What is next step?

 

[petehall347]

if so... when measuring the holders i get various readings... it just keeps jumping around to different ones

then try one holder to opposite end of fuse ..

 

[petehall347]

deoxit . if you can get it .

 

[Ryan Walton]

then try one holder to opposite end of fuse ..

What are we looking for here???

 

[petehall347]

What are we looking for here???

one probe to fuse holder .the other to both ends of fuse . .

 

[Ryan Walton]

one probe to fuse holder .the other to both ends of fuse . .

They both end up going to .01 with one side on holder other on the fuse....did it on both sides...same thing