Fixed My Casio A158WA Not Working: A Pure Unrivaled Marvel

It can be quite a shock when you look down at your wrist and find your Casio A158WA not working. I remember standing on a soggy platform at Manchester Piccadilly, checking the time for my train, only to see a blank grey screen staring back at me. This watch is a British cult classic, seen everywhere from Shoreditch to local pubs, because it usually just keeps ticking. When it doesn’t, you feel like you’ve lost a reliable old friend. Luckily, after years of tinkering with these digital gems, I have found that most issues are just minor hiccups you can sort out on your own.

Why Is My Casio A158WA Not Working?

The Casio A158WA is a marvel of simple engineering. It is tough, no-nonsense, and famously reliable. Because it has so few moving parts, it does not often “break” in the traditional sense. Usually, when things go wrong, it is due to a small environmental factor or a natural end to a component’s life.

Most problems I see in my workshop fall into these categories:

• A flat battery: The most common culprit by far.
• Screen fading: Often a sign of low power or poor internal contact.
• Stuck buttons: Usually caused by a buildup of daily grime or “pocket lint.”
• The 12:00 reset: This happens when the power connection is interrupted.
• Moisture ingress: Fog under the glass from a rainy walk or a accidental dip.

Quick Diagnosis Checklist (Start Here)

Before you grab a screwdriver, try these quick checks. This 60-second “triage” often reveals the root cause without any surgery.

1. The Light Test: Press the side button for the backlight. If it is very dim or makes the screen digits disappear, your battery is nearly empty.
2. The Angle Check: Look at the watch under a bright desk lamp. If you can see faint ghost-like numbers at a sharp angle, the module is alive but lacks “juice.”
3. The Button Feel: Press every button. Do they “click,” or do they feel mushy? A stuck button can sometimes freeze the entire display.
4. The Tap Test: Gently tap the watch against your palm. If the screen flickers, you likely have a loose battery clip.

Most Common Cause: Dead Battery

The heart of the A158WA is a tiny CR2016 lithium coin cell. Casio says they last seven years, but if you use the alarm every morning and the light every time you’re in a dark cinema, that life drops.

Signs It’s the Battery

• The screen is totally blank.
• The digits look “washed out” or thin.
• The watch resets to 12:00 whenever the alarm goes off.
• The light won’t turn on at all.

Battery Replacement Guide (Safe UK DIY Method)

If you want to save a tenner at the local jewellers, you can do this at home. You just need a steady hand and a tiny Phillips screwdriver (size 00 or 000).

1. Open the Back: Undo the four tiny screws on the stainless steel back plate. Keep them in a safe tray; they love to roll off the table!
2. Lift the Plate: Carefully lift the back. You will see a rubber gasket (a black ring). Leave that where it is to keep the seal tight.
3. Release the Clip: Use a pin or thin tool to unlatch the metal strap holding the CR2016 battery.
4. The AC Reset (Vital Step): Once the new battery is in, you must perform an AC reset. Find the hole marked “AC” and use metal tweezers to touch that contact and the top of the battery at the same time for two seconds.
5. Close Up: Ensure the rubber seal is flat and screw the back on. Do not over-tighten, or you might strip the plastic threads.

Expert Advice: “The AC reset is the step most people miss. Without it, the watch’s internal computer stays in a ‘locked’ state, and the screen will remain blank even with a brand new battery.” — Mark Fairclough, Horology Specialist.

Screen Is Blank But Battery Is New?

This is a common frustration. If you’ve just put in a fresh battery and nothing has happened, don’t bin the watch just yet.

Check the following:

• Did you do the AC reset? (See step 4 above).
• Is the battery upside down? The “+” side (the flat side with writing) should face up towards you.
• Are the metal tabs clean? If the old battery leaked a tiny bit, there might be a thin film of “gunk” preventing a connection. Wipe it with a dry cotton bud.

Buttons Not Working

In the UK, we deal with a lot of damp weather and dust. Over time, salt from sweat or general dirt can get into the tiny gaps around the pushers.

Quick Fix

Take a soft toothbrush and a tiny drop of Isopropyl Alcohol (or even just a dry brush). Gently scrub around the buttons. Press them repeatedly to work the dirt out. If a button is truly stuck, you may need to pop the module out of the case to clean the internal contact springs, but usually, a external scrub does the trick.

Watch Got Wet (The “Water Resistant” Myth)

The A158WA is labeled “Water Resistant.” In the UK, we often assume that means it can handle a swim. It cannot. It is built for splashes, rain, and hand washing.

If you see fog or droplets inside the glass:

1. Act Fast: Open the back immediately.
2. Dry it out: Place the watch (back off) in a tub of silica gel packets or a warm (not hot!) airing cupboard for 48 hours.
3. Avoid Heat: Never use a hair dryer or put it on a radiator. High heat can warp the LCD screen and ruin the watch forever.

Troubleshooting Table

I have put together this table based on my years of fixing these for friends and students. Use this to find your fix fast.

Symptom	Likely Cause	Fix
Blank Screen	Dead Battery	Replace CR2016 + AC Reset
Fading Digits	Low Power	New Battery
Buttons Stuck	Dirt/Grime	Clean with brush/alcohol
Foggy Glass	Water Entry	Open back and dry for 48h
Random Reset	Loose Contact	Tighten battery clip
No Sound	Spring Missing	Check small gold spring is touching back plate

Alternative Options: Casio A158WA

If you’re looking at the Casio A158WA, you likely want a simple retro digital watch that just works. I’ve worn Casio watches for over 17 years. From daily errands to travel days, they’ve been solid mates on my wrist.

The A158WA is cheap, light, and full of charm. But it is not perfect. The backlight is weak. The water resistance is basic. So let’s see how it stacks up against a few strong alternatives in the Casio family.

Casio A168 (A168WA-1) vs Casio A158WA

I’ve owned both. On the wrist, they feel like brothers. The A168 is a bit bolder. The key upgrade is the bright EL backlight. At night, that glow makes a big difference.

Feature	Casio A158WA	Casio A168WA-1
Case Size	34mm	36mm
Thickness	8.5mm	9.6mm
Backlight	Side LED (weak)	EL Illuminator (bright blue glow)
Water Resistance	Splash resistant	Splash resistant
Bracelet	Stainless steel	Stainless steel
Price (avg)	~£20–£30	~£30–£40

Rating:

• A158WA: 8.5/10
• A168WA-1: 9/10

If you hate dim backlights, the A168 is worth the small price jump. It feels like the A158WA with confidence.

Casio A700 (A700W-1A) vs Casio A158WA

The A700 surprised me. It is very slim. About 30% thinner than the A158WA. When I wear it under a shirt cuff, it almost disappears. It feels a bit more modern too.

Feature	Casio A158WA	Casio A700W-1A
Case Size	34mm	37mm
Thickness	8.5mm	6mm
Backlight	Side LED	Amber LED (better spread)
Design Feel	Classic retro	Sleeker, sharper lines
Water Resistance	Splash resistant	Splash resistant
Price (avg)	~£20–£30	~£35–£45

Rating:

• A158WA: 8.5/10
• A700W-1A: 9/10

If you want a thin digital watch that slides under cuffs, the A700 wins. It feels more “grown up” but keeps the retro soul.

Casio F91W (F-91W-1) vs Casio B640 (B640WD-1AV) vs Casio A163 (A163WA-1) vs Casio A158WA

I’ve used all three at different times. Each one shifts the vibe a bit. Same digital DNA. Different feel on the wrist.

Feature	A158WA	F-91W-1	B640WD-1AV	A163WA-1
Case Material	Resin (silver tone)	Resin (black)	Resin + steel bracelet	Resin (silver tone)
Water Resistance	Splash	Splash	50m	Splash
Extra Features	Alarm, stopwatch	Alarm, stopwatch	Alarm, stopwatch, countdown timer	Alarm, stopwatch
Look	Retro silver	Sporty basic	Rounded retro	Angular “stealth”
Price (avg)	~£20–£30	~£10–£20	~£35–£45	~£30–£40

Ratings:

• A158WA: 8.5/10
• F-91W-1: 8/10
• B640WD-1AV: 8.8/10
• A163WA-1: 8.7/10

The F-91W is the budget king. The B640 gives you 50m water resistance and a countdown timer. The A163 feels more edgy and unique. The A158WA sits right in the sweet spot for price and classic style.

Quick Summary of These 6 Models

All six watches share the same simple quartz digital heart. The A158WA is the pure retro pick. The A168 upgrades the light. The A700 goes slim. The F91W is cheap and sporty. The B640 adds better water resistance. The A163 adds bold design lines.

Each one links feature → benefit. Better light means easier night use. Slim case means more comfort. Higher water rating means less worry in rain.

My Final Thoughts on Casio A158WA

If you love clean retro style and want a watch you can wear anywhere, the Casio A158WA could be perfect for you. It’s light, simple, and fun. But if you care a lot about backlight strength or swim-ready water resistance, you may want to explore the A168 or B640 instead.

Based on my time wearing these around London, from Tube rides to weekend coffee runs, the A158WA feels honest. It does not try too hard. It just works.

In the end, this is not about price. It is about how it makes you feel. And for me, the Casio A158WA still brings that small smile every time I glance at my wrist.

When It’s a Module Failure

Sometimes, the “brain” of the watch simply gives up. If you have tried a new battery, performed a reset, and cleaned the contacts, but the screen is still dead or showing “garbled” nonsense, the module has likely failed.

Because the A158WA is so affordable (usually between £20 and £30 in the UK), it is rarely worth paying a professional to repair the internal electronics. At this point, buying a new one is the most sensible path.

Final Recommendation

If your Casio A158WA not working today, my best advice is to stay calm and try the battery first. In nearly 90% of cases, a fresh CR2016 and a quick AC reset will bring your watch back to life instantly. These watches are famous for their grit, and they rarely stay down for long. If you find the screen is cracked or the insides are rusty from a dip in the sea, then it is time to treat yourself to a new one. In the UK, you can pick these up at almost any high street jeweller or online. They are a true design icon, and even if you have to replace yours, the “old” one makes for great spare parts for your next one. Keep it simple, check the power, and you will likely have it back on your wrist by tea time.