Opinions on most efficient way to label leads for disassembly/reassembly

[leydenjar]

When pulling leads on a circuit board for disassembly of an amp during a repair, whether to pull up a circuit board, replace transformer, replace tube socket, e.t.c. how do you label the leads for reassembly?

I'm investigating the most efficient way to do this and wondered what people with experience do.

Thanks for any input.

[Enzo]

There is no right or wrong, as long as it gets the amp back together correctly.


First, do all the wires really need to come off? Instead of completely removing a circuit board to replace a part, I generally try to just free it from its mounts and flip it over enough to get at the solder side, wires still attached. Sometimes tipping the amp on its face helps. The amp doesn't always have to face the same way during repair.

But if you must, like pulling the output transistor board on a large PV power amp, I usually make a outline drawing of the board with a few landmarks added, then I draw lines from each spot on the board with a wire and what color wire it is.

Masking tape is easy to make flags with, wrap a piece around a wire and stick it to itself. It takes pen ink readily so you can write on it, and it is easy to remove by tearing. SO I can tag a wire with a post number or whatever it goes to.

Cables are often made with different size connectors so you can't hook it up wrong. But when that is not true, if I have two identical connectors with say 6 wires each. I get out a Sharpie marker and blacken one side of the connector, and also the same side of its mate. SO the plain white one goes to the plain white jack, and the one with the black line goes to the jack with the black line. More than one pair? OK one plain set, one set with one black spot, another set with two black spots. And like that.


Sometimes there may be more than one wire of a color. But if I have a black and blue next to each other, and a black and red over yonder, I can tape the two pairs together, eliminating the confusion over which black wire went with which color wires.


Marshall transformer? Most times I demount the old one and leave the wires on it. I mount th new one, and transfer wires over one at a time. Can't screw that up easily. Otherwize a square drawn on paper with tabs where the wires go allows me to draw in lines for red, brown, pink whatever, so I can put them right.


And sometimes I use knots. If I am in back of a speaker cab from a PA stack, I might have a half dozen wires coming down to the crossover from a hole in the filler stuffing. Again with the multiple black wires. I can put a knot in the end of one wire to mark it from the other same color. Of if I know they are pairs, I can knot two wires together. Just a simple overhand knot.

[olddawg]

Lately I take a picture with my iPhone camera before I start any repair. A while back I was adding a DC jack to an old MXR Phase 100 pedal from 1976. I had it clamped in a drill press to drill the case. The damn thing broke lose and spun sending the board flying across the room. It had at least 20 wires pull out. Luckily I found a picture of the guts on google images.

[Enzo]

Well there is a damn good idea. You never know when you might have wires come off without ever planning them to go at all. I am an old fart, and I don't have a picture phone, so I don;t even think of solutions like that. And if you have a schematic collection stored on your computer, storing a innards photo along with them is a fine idea. Good work, OD.


Sure wouldn;t be the first time I ever took Boss pedal apart and had wires break off.

[Enzo]

Well there is a damn good idea. You never know when you might have wires come off without ever planning them to go at all. I am an old fart, and I don't have a picture phone, so I don;t even think of solutions like that. And if you have a schematic collection stored on your computer, storing a innards photo along with them is a fine idea. Good work, OD.


Sure wouldn;t be the first time I ever took Boss pedal apart and had wires break off.

[52 Bill]

I've got to get a small cheap digital camera to keep on the bench to shoot gut shots. It took me a long time just to get a cell phone, I won't be upgrading to a new one anytime soon.

I masking tape groups of leads together when they all plug into one common area of a board. This can help when there are multiple leads that are the same color or the same kind of lead. And sometimes I'll mark the connectors with a Sharpie marker with a number or a letter.

[Prairie Dawg]

Whenever I'm disassembling an amp I always take as many photos as I can before labeling and marking the wires 25 or 30 is not unusual. I once spend an entire flight from Milwaukee to Boston going over a schematic because I'd gotten a couple of wires mislocated. Never again.

[Zer09]

Two words: eidectic memory. Steel trap.

[olddawg]

And how many times have you been in the situation: Do I believe the schematic or my lieing eyes, when working on an old (or even new) amp? Misprints, revisions, etc. Take a picture for a baseline.

[Prairie Dawg]

Two words: eidectic memory. Steel trap.

Works all right if you've got one but most people who think they do, don't. Study the work of Elizabeth Loftus-what people think they see is oftentimes at variance with what they actually saw. The only device with a photographic memory I trust is a photograph. Remember Reagan's Maxim: Trust but verify.

[Foxfire]

i just make a list of all the wires/colors and use a sharpie to put dots on the wires to differentiate them and i take a lot of pictures...

[leydenjar]

Well, I just wanted to see if anyone used any technique that I had not tried yet.

My current procedure is to:

1. Take several pictures w/a digital camera.

2. Label w/a Rhino 5200 labeler.

I never trust my memory and I always verify. It takes some time and I guess that's why I wanted to poll this topic.

Thanks for the input from everybody.

[leydenjar]

Well, I just wanted to see if anyone used any technique that I had not tried yet.

My current procedure is to:

1. Take several pictures w/a digital camera.

2. Label w/a Rhino 5200 labeler.

I never trust my memory and I always verify. It takes some time and I guess that's why I wanted to poll this topic.

Thanks for the input from everybody.