Peavey m 2600 old style one channel out

[dasmitty]

To start with I just want to say this is an awsome site ! Ive gleened lots of insight to many projects here. So here we go with the problem. Ive got this Peavey m 2600 channel B crapped out long ago This for my basement pa and i let my kids take for a year or so. when i got it back i notced a hiss coming from channel b then it quit and the clip light now stays on all the time on B , channel A works fine. from info from this site i was able to order new output transistors from peavey. I installed them and still not working and clip light stays on all the time, so tonight i dug in again and throught process of elimination notice it seems to be the board that mounts to the heat sink as i swapped it with the A channel and showed same problem but now on Channel A ive read the post about the TO-220 triac and think i located it but not sure, it looks like there is three of these things and two of them have heat sinks ? under them So......... am I on the right track ?? here could yous guys help a starving guitar player out , I need to get this up as now we need to use it for monitors when we play out Any info would be greatly appreciated and thanks to any who read this, By the way nothing on this board looks cooked or damaged at all but im going to switch the part that i think is the triac from the good board and see if thats the culprit right now.

[Enzo]

The triacs if present are near the speaker output connections as a rule. They are a three legged thing with the mounting tab. But if it doesn;t say SAC187 on it, it isn;t a triac. There will not be three of them in the amp.

Get the schematic from Peavey.

[Enzo]

The M2600 came out in 1982 and then the Mark V version in 1987. Neither one has output protect triacs.

[dasmitty]

ya i emailed them for one already but still waiting I swapped out the part i thought was the triac as it was bolted on the board but that didnt do it. i looked up the triac and this part resembles it but does not say sac 187 on it, and its not next to the speaker output. I am certain it is somthing on this small circuit board, though nothing looks fried ! Does peavey sell the whole board ? ill check in the morning, its a small 3X6 board dated 11/15/79 and possible a part number ? 99009083 and a 240sc on it. Hey thanks Enzo Ive read many of your posts on here and am also from michigan, portage in fact, yes michigan the unemployment wonder land, Things are gonna get better here right ? ? ? Ill try and post a pic for all to see what this critter looks like. but its late im hittin the rack and thankyou

[Enzo]

You won't get very far by just guessing and throwing parts at it. I doubt PV has complete boards in stock for amps that are 20-25 years old. And we don;t know that your problem is on that board anyway. What we generally do is troubleshoot the problem to find what is bad, then repair the board.

This involves taking voltage and other meter readings, and soldering parts on the boards in response to our findings.

I think you are confusing the shape of the part with what it might be. The SAC187 is in a three leg tab top TO220 package, but so are many transistors.

There is a power triac that the main power sdwitch controls, but if your amp turns off and on withthe switch, then it is OK. it is not on the main circuit boards. ANy other semiconductor part with a screw hole is a transistor.