Dewalt DW087 Self-Levelling Cross Line Laser

Just picked up a badly damaged Dewalt laser levelling unit. Old and damaged, can I bring it back to being useful again? I can only try.

What the listing stated:

think the batteries melted in the chamber. does not work at all.

EBay

Straight to the point, the words “severely knackered” I think, would probably be a more appropriate quote, however I must be patient and await its arrival.

When working and from new, these little laser levelling units retailed for approximately £175:00GBP. However they are of the older red laser model and new units use a green laser, so the older red laser version is now out of production, but still well sought after on second hand markets where it can still command prices in the £50-60:00GBP range. I’ve paid the princely sum of £6:00GBP for this one, so I’m very happy with that. If I can get it working it will go into my own tool kit for use.

Here’s a little about this unit:

A new DeWalt DW087 (or the DW087K kit) generally retails for around £178 to £185. However, because this specific model is an older red-beam line laser, used or refurbished units are widely available across secondary markets, typically ranging from £50 to £80 depending on condition.

The DeWalt DW087 (often sold as the DW087K) is a self-leveling cross-line red laser. It projects bright horizontal and vertical lines with an accuracy of ±0.3 mm/m and features an indoor visibility range of up to 15 meters. Powered by 3 AA batteries, it includes a built-in magnetic pivot bracket for quick metal mounting.

So. Basically it used by tradesmen and women to set up a visual laser projection around an area. Just think about putting up kitchen cabinets or worktops, and you’ve probably witnessed one of these in action. The one I have purchased sounds as if it is in a pretty poor condition, the lack of pictures showing the battery area speaks volumes and is probably hiding a crime scene, however I’ll just have to wait and see.

Assessment:

It has arrived. It’s as expected, looks like it’s been around a few building sites and most definitely does not work. The good thing is that the description of the batteries melting in the chamber was not so, in all truth it appears they have corroded the contacts a little, and one point of contact required to complete the circuitry appears to be broken.

It’s dirty no doubt about that, but it can always be cleaned.

The missing contact

There is a missing contact as highlighted in red, in the picture above. This connects with the battery contacts in the battery lid. When a circuit is made the level will work. There is a small piece of metal strip at the base of this hole, the remnants of the contact that should be there. I have managed to get the unit working by temporarily putting a small spring in here to bridge the contact. This will have to be replaced or repaired though.

Repair:

The first thing to do is to get the unit disassembled, and that is surprisingly easier than I thought. Four screws later and the body can be pulled apart. Another two screws removes the battery flap. Easy.

There are a couple of rubber gaskets that fit in between the two parts to ensure an airtight seal and to stop the ingress of dirt. I have given the lenses a clean with a camera lens cloth, I have cleaned both inside and out of the window and given a good blow through with some compressed air. I have used a multimeter on the power led in diode mode just to check that it is operational, and it is. There is nothing else needing attention within the internals.

Turning my attention to the battery chamber and battery lid I give both a thorough clean, the negative terminals in the battery chamber are cleaned with an IPA solution to improve their appearance, the whole chamber is cleaned in the same manner and is looking good.

There was a collection of what appeared to be iron filings where the battery lid joins the body, and this is because on the opposite of this point, there is one of two strong magnets that keep the lasers level. Holding the unit over a bin and lifting the magnet out ensured a nice little rainfall of iron filings into the bin and not all over my workspace. With the magnet now replaced I gave this same area a further good clean with IPA.

The battery lid has been left to bathe in a dish of white vinegar to help remove the remainder of the tarnishing to the battery contacts attached to it. It’s worked ok, a final tidy with a grinding pen has brought this up well, looking a lot better than it previously looked.

I now need to look at that broken contact.

The wiring for the contact has been hot glued into place on the reverse of the battery chamber. I used some IPA to loosen the old glue and that allows me to remove the remainder of the broken contact. The top part missing from the inside of the chamber has long gone. I will have to fabricate a replacement myself. The wiring you see above was also hot glued to a plug on the main circuit board. Again, an application of IPA softened the glue and I was able to remove the plug from the circuit board to be able to work freely on the battery chamber. When the work is complete I will re glue both these items back into place prior to reassembly.

I’ve formed a small contact out of a piece of pliable metal to use in the device.

It fits nicely and is cut in such a way that it won’t push through into the chamber when a slight pressure is applied. I’ve hot glued both surfaces that I had removed glue from in the first place to gain access. Now the unit is being reassembled they’ve been glued just as they were previously.

Now the unit is back in one piece it’s now time to reattach the battery chamber lid, and in time honoured tradition, I’ve daubed my nick name on the lid, as this will now go into my toolbox in my garage.

Now all that is left to do is switch it on.

And it works just fine….

Let’s now just give it a practical clean, it’s a working item for rugged situations so it isn’t going to look “Shop” new. But it will be an awful lot cleaner.

Result:

A tool that originally retailed for £175:00GBP and available on the auction sites, in good working order of between £60-£90:00GBP was purchased, non operational for the grand total of £6:00GBP. If that isn’t a bargain then I don’t know what is.

For little more than a couple of hours work I now have a valuable practical item to add to my toolbox because someone else just couldn’t be bothered to spend the time on it to get it working. Lucky me.

Definitely another item saved from landfill, with a new lease of life that should go on for many more years yet.

I’m very happy with it, this was a pleasure to work on.

Many thanks for passing by, as always it is very much appreciated.

Laser Microphones

Interesting look into building your own Laser microphones in a James Bond/KGB/CIA style.

Enjoy. Just don’t be nosey.

Sony Discman D-141

Assessment and fault finding….will it work ?

Double trouble here as I’ve purchased two of them.

Sony Discman D-141 – double trouble

These variants are from 1994 just around the height of the capacitor plague problem. As I’ve already dealt with a D-121 version this week that was riddled with the issues and being only a year older, I’m not too hopeful that these two will be any different. They both have the same issue being that they turn off after about 10 seconds, this could be due to a number of issues, let’s get them unpacked and get an initial inspection done.

On initial inspection they both appear to be quite tidy considering they are 30 years old. One is missing a disc capstan however i do have a replacement from the old D-121 that was added to the spare parts box earlier this week.

Both start up, spin and then stop, sometimes showing a no disc error, sometimes not. The good news is there is no sign of corrosion on either unit.

Time to open them up….

I used the old donor D-121 from earlier in the week to replace the missing capstan on one of the units.

On opening of the cases the boards looked ok. No signs of corrosion or plague damage, this was a good sign and it was now time to look a little deeper.

Looking at the board

I did the standard clean of the lenses with IPA, I re greased the worm gears and rails but none of this alleviated the issue of the discs stopping just after start up. I did some continuity checks and component checks, all seemed ok. All buttons worked, all switches worked, something just wasn’t right. I decided to check the output of the laser adjustment pot and this was extremely low. I spent a good hour on the first unit and a similar time on the second trying to adjust the range up and down before realising that after 30 yrs both lasers seemed to be at fault. No adjustments improved the output.

Faulty laser assembly removed and replaced

I was facing the fact that I’d now have two more failed units to go with the D-121 earlier this week. Then I thought why not try the laser out of that failed unit?

It worked. The D-121 donor unit was compatible with the D-141 and after a few minutes adjusting the laser we were able to play an audio Cd.

We have life

This week I have looked at 4 faulty units and managed to get 2 fully working with a third one needing a replacement laser sled when one becomes available. I have one spare redundant unit that has been indispensable for the repair of the other units, in theory i potentially have 3 out of the four available.

All dressed up

I won’t be wasting anymore time on Discmans in the foreseeable future. They had their time and digital sound has obviously pushed this medium in to the dark distant past. The units are becoming life extinct and it’s like performing knee surgery on an elderly individual, you are improving their quality of life for the moment until the ravages of old age take over. Bit of a crude analogy I know, what I’m saying is steer clear of these as they are going to be trouble, people seem to think they are worth a fortune and are charging ridiculously high prices for something that just about works.

It’s been fun though and I have learned a lot from it so it can’t all be bad.

Good people, stay safe. Thanks for passing by.