Peavey CS 800 (X) Minor Maintenance

[TomCarlos]

Friends....

I was given a Peavey CS 800 (X) series amp that needs some minor work. Before I donate this amp away, I want to address a couple problems.

First, the good news... The amp passes a signal on both channel and with an 8 ohm load, I was measuring around 40.5 VRMS on each output. So the amp is "working." But before I do any serious testing, I need to deal with the issues.

This amp needed a major jet blast of air to clean the pc boards, walls, cavities etc. I removed the fan, cleaned and lubed, and it is running ok - Loud, but ok. Hey, it is a big 110V AC fan.

For now, I believe the only electrical problem is with a resistor in the fan circuit. R103 (400 ohm, 20W) was burned right off the PC board (schematic attached). One side of the resistor melted the metal mounting stud off the board. The bottom side of the PC board also shows burn signs. So I will need to find a replacement for that resistor and find a way to mount it securely. I am thinking I might need to raise that resistor off the pc board a bit.

The other thing that needs replacing is the XRL connector on the input. One of the pc boards is hard to remove. It looks like I might need to remove one of the filter caps? Is there an easier way to get that board out?

Speaking of removing pc boards... If the main power amp board needed repair, how would you get to that board? From the bottom?

Tom

[Jazz P Bass]

The main amp comes out from the top.

You just have to remove about 20 screws.

[TomCarlos]

Oh what fun that will be someday .... :-)

I ordered the resistor and checking the parts around it - especially C50. The cap had some black marks on it but it appears to be ok. So by next weekend, I should have this resolved.

I have an extra Neutrik XLR and will try to get that other PC board out. I think I need to remove one of the big filter caps. I don't see any other way of pulling the pc board out. The banana jacks are too long!

[Enzo]

And so how many screws hold the cap? If it has to move, then move it and get on with your life.

If 400 ohms is hard to find, 390 ohms is a standard value and easy to find.

Notice the bundle of wires from the power supply over to the main boards is extra long and folded in two with a couple cable ties? (top of photo 4) That slack is what you use. Snip the cable ties so that cable can be stretched out. The board assembly is bolted to the rear panel. Dismount the rear panel and remove some screws underneath and the whole board/panel can be lifted out and set behind the amp. Now access is easy. Oh, if memory serves, you might have to remove a screw or two on the front panel, and maybe the knobs too.

Isn't the XLR one of those guts only ones PV loves to use on their box mixers?