Peavey mkiii standard head HELP!

[RandyJoHobbs]

Hey guys, been a while since ive been active on here. I've just aquired a peavey mark 3 standard heas and she wont turn on. No power or anything. anyone have any idea what could be the issue? The fuse looks fine...

on the plus side, I also in the same day aquired a 2x15 cab loaded with JBL E140s and a Peavey combo 300 amp for just $200AUD!

 

[BogeyBass]

Awesome deal on those jbls should be alot of fun.

As far as the amp looks like alot of weird bad solder connections. And can't tell from the pictures but possible missing components.

Looks like somewhat fresh flux, and someone jumped a diode across few traces.

So likely was a original issues. And then someone did a not so great job at fixing it. Or possibly got it too work, but missed or worked around whatever was wrong in the first place.

I'd look at where the fresh solder joints are and try to figure out what was originally wrong. Then clean up the work that was done.

There is some very very bad soldering joints so if you lucky those just need touching up.

 

[agedhorse]

That's standard wave soldering of Peavey boards without solder mask. Nothing weird about it.

Proper troubleshooting techniques will quickly identify what's not correct and where.

How much experience do you have troubleshooting solid state power circuitry? Do you have a scope, signal generator, DMM and current limiting variac?

 

[RandyJoHobbs]

I dont have any of that... i can post a pic of the schematics if that helps?

 

[agedhorse]

How do you expect to be able to troubleshoot then?

I think you need to find a tech to help you get this fixed,

 

[Roland GR 88]

I dont have any of that... i can post a pic of the schematics if that helps?

There's no chance you'll get anywhere here with pics or schematics. You need tools not advice. If it was free - which it should have been - put $75.00 into a trip to a tech and cross your fingers.
Good luck

 

[crazyBassClown]

. No power or anything. anyone have any idea what could be the issue? The fuse looks fine...

If the problem really is no power at all, the problem is most likely fuse, power switch, power lead, or transformer.
If you don't own a multimeter and know how to test these then like has already been mentioned, send it to a tech.

 

[crazyBassClown]

and someone jumped a diode across few traces.

I have a perfectly functional peavey with similar diodes on the underside. I think it was common practice at peavey.

 

[RandyJoHobbs]

Took the soldering iron to the board this afternoon. Gave it a spray with elecrical contact cleaner and replaced the fuse. She is now WORKING! . Thanks for all your advice guys!

 

[fnordlyone]

Took the soldering iron to the board this afternoon. Gave it a spray with elecrical contact cleaner and replaced the fuse. She is now WORKING! . Thanks for all your advice guys!

I was about to post that at least you have the 300 Combo head as back up-- if the markiii was gooched by previous owner. Old Peavey is pretty tough, though, and looks like you got two heads ready to send 300 watts and 2ohm loads. I like the 300 combo head's pre with the paramid control; seems a touch louder than my older head. I've got a markiv that I've never had to open up (1982)... use both daily. Congrats on Epic amplitude/cabbage score. I split my 300 combo into separate head and built a much larger ported cab for the 15" BW. No more beam; cab is tuned down to 30hz.
fnord!

 

[RandyJoHobbs]

I was about to post that at least you have the 300 Combo head as back up-- if the markiii was gooched by previous owner. Old Peavey is pretty tough, though, and looks like you got two heads ready to send 300 watts and 2ohm loads. I like the 300 combo head's pre with the paramid control; seems a touch louder than my older head. I've got a markiv that I've never had to open up (1982)... use both daily. Congrats on Epic amplitude/cabbage score. I split my 300 combo into separate head and built a much larger ported cab for the 15" BW. No more beam; cab is tuned down to 30hz.
fnord!

Funny you mentioned turning the 300 combo into a head.. I've just done that! running the combo 300 with the jbl 2x15 cab and the sound is incredible! now just to find an old T-40 Bass to go with it......

 

[Count Bassie]

...I split my 300 combo into separate head and built a much larger ported cab for the 15" BW. No more beam; cab is tuned down to 30hz.
fnord!

Funny you mentioned turning the 300 combo into a head.. I've just done that! running the combo 300 with the jbl 2x15 cab and the sound is incredible! now just to find an old T-40 Bass to go with it......

Pix or it never happened...