CoupeGTAddict

If your VDO analog quartz dash clock is dead, try this before giving up - pulling the instrument cluster out to work on it is the hardest part! (Refer to the shop manual for that part...) Pull the white plastic collar off of the blade terminal near the center of the back, which releases the +12V supply strip. Take out 2 screws to remove the clock module. Desolder the joint at the end of the brass strip (ground connection) and remove two slotted screws to release the black backing plate. Under the backing plate there is a sponge rubber spacer - remove it as well. You will see two electrolytic capacitors at one end of the PC board; they are likely to be the problem. Mine were marked "100/16", so I went to Radio Shack and picked up a pair of 100 micro farad 50VDC rated electrolytic capacitors as replacements. After desoldering the original caps (replace one at a time to keep polarity of capacitors correct - it matters with electrolytic caps), the new ones fit right in. Soldered 'em into place, trimmed off the extra lead lengths, reassembled the clock, and tested it with a wire from the car battery to the clock's blade terminal while touching the brass ground to the other battery terminal. Perfect! Now, all I have to do is finish recovering the dash (badly cracked, much more work...).

Note: Thanks to the Mercedes Benz repair forum (last posted to the thread something like 4 years ago...) that provided enough info to motivate me to give this a try.

boxerfan

consumer grade are typically 85C parts, Industrial are usually 105C parts. Going with a higher voltage helps withstand higher temps as well. I can't recall what the next step up from 105C parts is off the top of my head but you can go higher still. If gets mighhty hot under the dash... but then again.. they lasted this long.... the clock will likely outlast the car now!

Well done!