1240/Repairs
No V-sync
See Report by Bernd (German)
- Symptom: Screen V-sync was very unstable, adjustment range insufficient.
- Root cause: C521 (1 μF) in phase detector circuit was found installed with incorrect polarity, presumably ex factory (original-looking solder joint). High leakage current resulted.
- Fix: Replace C521 (install with correct polarity).
Touchscreen
Description
- The 1240/1241 will tend to accumulate dust because of the large quantities of air flow needed to ventilate the device. The front screen uses a combination of LEDs and phototranstistors to sense presses. Dust and other particles can accumulate on these components leading to failure.
Fix
- Page 83 of the 1241 Service Manual addendum (PDF) explains the procedure to clean the elements.
Backup battery
Description
The 1240 and 1241 retain configurations in battery-backed RAM. In most instruments, the battery is a Catalyst Research 3440LP. Over time, this battery will deplete and unltimately leak. A leaking battery can destroy components, PCB traces and metal.
Fix
The old battery can be de-soldered and wires can be soldered in to connect a new battery. It is up to the user to decide what type of battery they will use, as long as the battery voltage is about 2.9 V. The new battery can be placed wherever appropriate.
Conclusion
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So far I've had no problem with this fix I've had the battery installed for over a year. I used a CR2032 battery, but it's not the best solution because the analyzer will try to recharge it.