yes sir will def be checking that.  glad to see you recommend using mouser or digikey....was tempted to go elsewhere.
if there is anything else I should get from there let me know I hate to spend $7.99 on a $3 order.  maybe some of the other peavey-esque chips..just to have on hand.
I ordered a function generator today....that should make me learn the signal path
anyhow thanks for all of the help

hello all
I have a realistic power supply 13.8v 3A
I want to hook up and test an old 7808CT removed from my amp.  I dont know much but I am thinking 3 amps is gonna blow this thing up or melt it....
(I dont want to reuse it this is just me trying to learn some stuff...)
I also have a topwon 6303A that I havent unpacked yet maybe I can dial current down..
also I read the data sheet on some of the semiconductors...about a I could find was the output current.
I did some preliminary diode type tests per youtube...it seems to be good idk....if its good its good I will replace it regardless that dag blasted glue had to come off anyway.  Anyhow mucho beer and pizza to all I really appreciate it all the help I have gotten here.
regards
Wesley

well guys I kinda inadvertantly jumped the gun.  I wanted to remove the "silicon" blob encompassing 7808 only to discover it was armor piercing resistant hot glue.  so I resorted to some medieval methods ie soldering iron and picks etc to get all of that crap off and out of there.
meanwhile I wanted to short that diode and measure but it was getting late and it was so tiny I was trying to think of how I could achieve it....then I was wanting to lift those links as advised so I knew I would have to turn the board over...which I did...and then that poor 7808 had suffered so much abuse I just desoldered it and put the board back like it was. 
go figure in other places the hot glue just peeled right off.

anyhow the marking on the device is

"MC (MC logo)

7808CT
QQ8606A"

thanks for your help

thanks guys
I havent ordered any components yet but aside from the physical dimensions is something like this ok

Linear Voltage Regulators 3 Pin 1.5A Fixed 8V Pos Vltg Reg

I want to do as much testing as possible to learn

regards
Wesley

btw Happy Easter or whatever your endeavour

ok im back...the three transformer wires...red/yellow with red on each side...I get 13.6v a/c testing each side to center

on the big c57 I get 17.6v dc

on the little c58 I get 0.646v dc

then I tracked down cr24 and got dizzy trying to remember arrows and cathodes.... bands.

I messed with it quite a while got lots of different readings...but all under 1v...time for refresher course

hth btw I will look to subscribe or contribute as gratitude for the help I have received

regards
Wesley

yes sir thanks that is a monumental (to me  homework assignment but will be a great learning experience

I will report back with results

update
all three 4558 have nearly identical readings
the two socketed 4558 have -9.4v on pin 4 and -0.64 on pin 8
the 4558 that is not socketed has -0.64v on pin 4 and -9.4v on pin 8

all three measure about 8.8v pins 4 to 8

now moving on to 7808...the good news I think I found it...the bad news is it is underneath about a gallon of silicone

I cant get to the legs at all...I could probably lift the board out and measure that way....

thanks again

also now going back I see where mr TV did say measure each one....doh 

guys...im sorry
in my haste I didnt notice there were three RC4558Ps

because I was at work today and wanted to see where I had been on the schematic and look at what mr Phatt discussed and then i saw them.  now I am at home and see them on the pcb as well.
my apologies.
some good news though maybe it looks like two of them are in sockets
 
so let me look at the schematic and try to figure out which one I took measurements on.

thanks again

sorry forgot to add...the speakers were disconnected during the testing...dunno if that matters

well I googled 4558 pin out, removed the chassis and turned it on and measured the pins 4 and 8

I need to find my mini grabbers because I was slip slidin away like Paul Simon worried I was going to short something out.

anyhow
pin 4 to ground -9.36v

pin 8 to ground -0.64v

pin 4 to pin 8  -8.73v

all measurements rechecked a few times

btw my chip or whatever had these markings

731 A B
RC 4558P

with a Texas Instruments? logo
and thank God for that circle mark I guess that helped me know which way was up...TM Richard Pryor

 

also I noticed a nice wooden adjustable chassis holder in a D-Lab video I thought he had bought it but a vendor sent it to him.
I want to put something like that together sure would be nice

thanks for the homework assignment I was going to check in and say I bid on a scope earlier today but didnt win. 

well....Im off to find pin 4 and pin 8 

thanks again guys
I tried running both preamp out to an old working Crate 15 combo and it was silent.
I am in this for the long haul so I am working on making a signal input like 1 khz connected to a guitar cable for testing.
then for trying to track the signal I might make an audible guitar cable plus capacitor to amp type signal tracer or maybe a cheap scope.

 thanks for the help

thanks guys I have tried a little bit of different things....trying to upload a pic of the back
I need to figure out how to do that and get back to you.
but all I have on the back is three jacks...footswitch, preamp out 1, preamp out 2


thanks again