Omega Speedmaster 1620 resto

[767Geoff]

Hello,

just a short pictorial of the Omega Speedmaster module 1620, case model 186.0005.

Well beggars can't be choosers and the price on the following non-working watch was 90 Euros. I took a gamble but I new I could source a new crystal for cheap and new old stock battery tabs although at the time of purchase I did not know what was wrong with the watch. The before pictures are from the seller and I did not take any myself of the 'before condition'.

So the watch was sold as non-working without any hint of damaged or broken battery tabs. Of course the non-working light bulb was not mentioned. What you see is what you get. So I bought it!

before pictures (sellers pictures):











Now for the after shots after the following was done:

- crystal and crystal gasket removed.
- case refinished with polished facets surrounded by brushed finish as per original.
- movement stripped, cleaned, staining removed and with some minor signs of battery sulfate precipitate.
- jury rigged after reassembly and module functioned perfectly.
- battery tabs replaced with new old stock.
- found broken bulb (filament) probably from the same shock that chipped the crystal. bulb replaced with spare NOS Seiko bulb.

Had two mesh straps to try, as watch did not come with original Omega strap. I prefer the finer mesh which had to sized to 20mm inner with the outer at 22mm.

The first strap:







The finer and final strap:







and the old crystal removed and some spare battery tabs, I have the iconic 186.0004 inbound so I may need a couple of the spares for it:



There you have it, a restored fully functional watch, albeit with a different (black) reverse painted dial and a non original light bulb and strap. Very well made movement with a jumper to switch from 24 to 12 hour formats. 5 seconds per month although mine is 0 seconds after 3 weeks. Nice light feel on the wrist with the fine mesh strap.

The pushers had to be released from the gummy goo. Someone repaired it by using pliers on two of the pushers. A thorough cleaning and lube brought these back to life, and the scratches were polished out as the pushers are stainless steel.

Cheers, Geoff

[wzy-hman]

Very nice. You'd never guess its the same watch. I doubt anyone will notice or be bothered by the light bulb On the subject of which, how do you go about verifying what bulb is in there and what a compatible replacement might be? I have an Omega Sensor 1640 which has a dead bulb. Maybe I need to try my hand at changing it! Thanks

[767Geoff]

Quite honestly, I took a stab at it. There are two 1.55 volt batteries in the Omega; one drives the bulb and the other drives the circuit.

So the Seiko bulb has the correct voltage, barring any step up amps (just kidding).

The trick is to find a junker donor seiko which has soldered bulbs with long enough ''legs" (wires) to reuse. Test with an ohm meter for continuity and I use a battery powered fine pointed mini solder iron.

The neat thing about the Omega unlike the Seiko counterpart is that the Omega has a clear plastic lens that the bulb fits into. This clear lens transmits the light evenly over the entire panel. You don't get a bright end and a dark end to the display.

The 'legs' on the bulb must be long so that you can fit the bulb into the recess in the lens.

Geoff

[Kasper]

Great restoration, job well done.

I like the fine mesh band...gives the watch the (high quality/price) Omega look it deserves.

[charger105]

The 1640 has a bulb which protrudes vertically through the circuit board.
I have found it difficult to find a donor bulb with both legs coming from one end only.
Most Seiko bulbs have a leg at either end of the bulb.

ESA LCDs do use such a bulb, so if you have a junker, this could
be a good candidate.
Rgds.

[wzy-hman]

The 1640 has a bulb which protrudes vertically through the circuit board.
I have found it difficult to find a donor bulb with both legs coming from one end only.
Most Seiko bulbs have a leg at either end of the bulb.

ESA LCDs do use such a bulb, so if you have a junker, this could
be a good candidate.
Rgds.

Important and useful tip! I know what I'm hunting for now. Thanks to both you and Geoff

[vespa78]

very nice job done !
milanese band looks good, I guess it's pretty hard to find an original band for reasonable price...

[767Geoff]

Good point on the bulb, legs vertical or protruding out the end. That is why you need a bulb with long legs. I bent the wires vertically at the end of the bulb at 90 degrees and then had to bend again as the solder point on the PCB does not line up with the recess in the lens.

Yep the milanese fine mesh goes well on the slim case, the larger mess needs a more robust case, perhaps the speedy 1620 that is on its way. There is a similar strap to the original (style) for a different (diverant sp?) case but it is Omega from the 70's on the Bay. The seller wants 375 US$. Considering a relatively nice looking one of these watches can be had for 800USd I think I will pass.

I will keep an eye out for one. It is too bad they don't taper these Milanese like they didi in the 70s. Also had to file the 22mm ends down to 20mm to fit the case with the correct width to line up with the case edges.

Anyone know where a tapered, pre milled 20mm ends with 22mm link width can be had?

Cheers, Geoff

[767Geoff]

Hello charger105

Ah, reread the post about both wires extending out of one end and the bulb being vertical. Interesting, the bulb I replaced was lying horizontal, that is parallel to the PCB (in the same plane). It had wires extending out of each end of its longitudinal axis.

In this case it was identical to the seiko bulb I used to replace it. Maybe mine was an attempt at a repair although the older joints looked perfect. Of course so do my solder joints

Maybe the case thinness (186.0003) has a different bulb requirement versus say the Speedy case (186.0004) which appears to be thicker? When I get the 186.0004 I will take a look at it.

Due to the recess in the lens one must be careful when assembling the two sections of the module together. I forgot on the first attempt and flattened the bulb to the PCB. when I tested the bulb in a dark room the light was useless, then I remembered, oops, the bulb must be in the recess for the prism effect of the lens to conduct light.

Reset the bulb with a fine pair of tweezers and voila, a working bulb and lighted display.

Geoff

[charger105]

Hi Geoff.
I forgot to mention..........top job ! Looks great.
All of the 1620 modules are the same as far as I know. The bulb is parallel to the PCB, with legs out each end. They then bend down, across under the bulb and then down again to solder onto the pads. You need to get it into the right position to line up with the recess in the rectangular plastic thingy that goes behind the LCD. It's one of the best backlights around......very even light distribution.

The 1640 (Sensor Quartz) is what I was describing earlier. As mentioned, the bulb protrudes vertically throught the PCB:

1640.png

The legs need to come out one end of the bulb only, and are soldered on the other side of the PCB:

1640_1.png

An ESA LCD has such a bulb. The one's I've seen are glued into the little tube attached to the prism thingy. Just cut the tube, and peel the bulb away:

esa.png

There are probably other modules with similar bulbs, but I can't think of any offhand.
Rgds.

[wzy-hman]

When replacing the bulb is it possible to use conductive glue instead of re-soldering? Glue would be easier to apply but I don't know if there might be any practical disadvantages compared to re-soldering

[charger105]

Conductive glue will be fine.

Using glue will mean:
1. You'll have to wait for it to dry.
2. It'll be more difficult to to reverse if you need to replace the bulb again.
3. Has the potential to be messy.

But if you're more confident using glue, then go for it !
Rgds.

[wzy-hman]

Hi Charger105, you convinced me with your point 2. I better practice my soldering.

Hi Geoff, what brand/model no. is your "battery powered fine pointed mini solder iron"? Sounds like something I should consider given my existing one is an old clumsy plugged-in basic one.

Thanks to you both!

[767Geoff]

Glue,

In a word messy, at least for me! As an aside; if you glue a wire bond on an led, and mess up, the glue interferes with future wire bonding (Hanno does wire binding).

There may be better ones but it bought four of these at my electronics store on clearance sale for 4 bucks each. Google Pro's Kit SI-B161 and here are two results:

Pro's Kit
SI-B161
4.5volt, 9 watt

http://www.productreview.com.au/p/proskit-si-b161.html

http://www.ebay.com/itm/Brand-Proskit-SI-B161-Portable-Battery-Operated-Soldering-Iron-/170877366158

[Seiko Kid]

Some of the Seiko A type 0624/34 use bulbs , ahem lamps ( my electrics teacher always told me bulbs grow out of the ground :) ) that have both legs at the same end