peter1965

The green fluorescent clock display on my ’97 ES 300 has dimmed over the years (it’s a 1997 car after all) and it became unreadable eventually. When the “H” or “M” buttons on the clock were pushed the display brightened.

Over time the electronic joints on the clocks’ printed circuit board (PCB) go “dry” or high electrical resistance, and the fix is to heat up the joint, reinstating the solid connection from the component to the PCB.

Removing the clock:
1. Remove the air vents facia (prised them out of out of the dashboard with a screwdriver wrapped in tape).
2. Unplugged the wiring from the clock & the hazard flasher switch
3. Remove the clock from the vent fascia;
4. Remove the clock assembly from its housing by levering up the 4 clips;
5. Remove the 2 screws holding the back cover on the clock – carefully as there are 4 small springs in there that will fall out if you aren’t careful.

There are 4 small Surface Mounted Device (SMD) resistors (small black lumps with 101 written on them) soldered onto the clocks’ PCB near the small pads that the H and M buttons mate with (via conductive rubber pads on the back of the buttons).

There are two ways to do it:
1. The easy way:
o Slightly heat up one end of each resistor at a time (allowing the other end to cool before you do its mate) and,
o With a low power (no more than 25w and with a very fine tip) soldering iron apply a very small amount of heat to each of the pads. This is often enough to fix the dry joint.

Using as little heat as possible is important as both the component and the PCB are easily damaged.

2. The thorough way:
o Heat each joint and using desoldering braid (also known as solder wick) to remove some of the solder from each end of the resistor (again, doing one end of each resistor at a time;
o Allowing cool-off time, (and again using as little heat as possible) resolder each of the pads (one end of each resistor at a time) using fine electronic solder. Apply as little solder as possible to do the job.

Note that this was done on an Australian-market car, so other cars may differ.

Reassemble it and all is good.

Cheers
Peter.

kaldES98

Nice write-up.. I just flick the clock with my fingers and it stays bright for a while haha.

peter1965

lol thanks... yeah i was doing that for a while too... eventually i got fed up with it and it just got dimmer and dimmer... cheers

knarf0117

Excellent Post. I have a 99 ES300 with long term dimming and finally went out altogether. I made the recommended repairs, and the clock is as good as new. Thank you!!!

aikibro

My clock is fine, but I'm wondering, is there anyway to change the color of the light from that pea green?

Kimosabbe

I followed your precise instructions and now my clock is working like new! Thanks for taking the time to share your knowledge.

wmj259

I'm having an issue with my clock as well, except instead of being low in light, it starts off bright when i start the car, but it dims out till I can't read it anymore.
I'll try this out and see what happens. Could solder be added?