Randall Rh200scg2

[yardsale]

Hello to everyone im new I have A RH200sc g2 head that i need 4 diodes for all i can see on them is h48 so i went ahead and ordered http://www.sparkfun.com/products/8588, the diode location on the board is j17 any help is very appreciated. did i get the right ones?

[J M Fahey]

Dunno, post the schematic or at least a picture.
How did you decide they needed replacement?
If they are small signal 1N4148 class, they probably are used for clipping the audio signal for distortion, that's a very light duty which never burns anything.

[yardsale]

My repairman told me they need replaced and he cant find them

[tonyharker]

I think thats going to need more than a few diodes

[yardsale]

yeah hes got everything but the diodes.

[joecool85]

Goodness gracious!  What happened to that poor amp?  Not sure if it'll be easily repaired, quite a bit of scorching for sure.

[J M Fahey]

Wow !!
That's what happens when proper sized fuses are replaced by larger ones, or even bypassed, for a late Saturday night "repair".
Saving on a 10 cent fuse turns a $50 repair into a $200 one.
Sorry.
I see two identical power amps there (is this a stereo chorus amp?) so at least the right one , which may be fine, may serve as a reference for the left one.
Those diodes probably *are* 1N4148.
Since they are very small and glass encased, often the label is printed in 3 lines, as in:
1N
41
48
or in 2 lines:
1 41
N 48
and you read N as H.
I'd play it safe and replace *all* transistors and diodes at once, plus any toasted parts, plus turnin the amp on using a series lamp bulb limiter and without any speaker or load connected, until you are sure you do not have DC on the output.
You will have to sand or scratch away all carbon on that PCB, because it's conductive and will short otherwise good parts.
Good luck.
PS: you will probably have cut, cracked or burnt tracks.
Try to "reverse engineer" (a.k.a copy) that schematic; some minutes with paper, pencil and a good light (plus good glasses if needed) will help a lot.
You have the unburnt side as a reference.

[yardsale]

thank you very much for the usefull info i did get the 1n4148.
you guys are awesome