Issue with SA-7800

[petehall347]

ok . now we to rewind back to where the misunderstanding about diodes and test points happened . and get those voltages at the diodes .

part of the confusion comes from here ....
TP is test point . otherwise known as pin .
i know you will be confused by that but will figure it out later ..its not important right now anyway .

 

[Ryan Walton]

Okay so youre saying d27 is on the other side of the board....did i not test this component when i tested it before then?

 

[petehall347]

you were in the wrong place . its ok though . just get on the same page and we will find the problem .. page 34 in the service manual .

 

[Ryan Walton]

Service Manual I have is only 29 pages

-edit- nevermind... was looking at pdf page numbers... okay i'm on pg 34... what am I looking for?

 

[Ryan Walton]

Im there

 

[petehall347]

find those diodes .. scrape the black off the legs to get a good connection .

 

[Ryan Walton]

Okay so this is only "27" i see on the board... it is to the right of the heatsink and right next to the big black capacitors...is this not it?

 

[petehall347]

i posted a pic of a diode .. they are black with a line right round one end .

 

[Ryan Walton]

and i'm not seeing anything on this board that looks like that and labeled d27

 

[petehall347]

was hoping for a board view in the manual but cannot find one . stand by

 

[Ryan Walton]

Dont know if it matters or not but AC for q34 and q35 is measuring 33.5v each

 

[petehall347]

dc volts tp 15 and 21 ?

 

[Ryan Walton]

Okay, so I think I may have found some (4?) diodes in this picture... which one is d27 though? You can also see the fuses at the top of the pic. Also, what is that white rectangle directly below the bottom most fuse with the metal piece on top that says "577" on it? Because it looks like from the schematic d27 should be right about there?

 

[petehall347]

one of the smaller ones .

 

[Ryan Walton]

dc volts tp 15 and 21 ?

lol...okay we're bouncing around Pete... lets stick to d27?

 

[Ryan Walton]

one of the smaller ones .

if that's the case... according to schematic it has to be the one on the farthest right... brb

 

[Ryan Walton]

okay pretty sure that was d27.... it measured 47.3!!!

 

[petehall347]

sorry its late here ..will catch up in daylight ..

 

[Ryan Walton]

ugh... is anyone else awake that can step in here? I'm trying to get this figured out and been working on it since Monday

 

[petehall347]

please be patient . this is not easy .