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).

Error message: INTER PROCESSOR COMMUNICATION FAILURE

Description

• Error message when unit is turned on: INTER PROCESSOR COMMUNICATION FAILURE
• The red LED's on the A09 Control processor board and A10 I/O processor board is also flashing in a cyclic loop.

Fix

• Cleaning the connectors / reseating all boards connected to the A08 interface board may solve the problem.
• A leaked lithium battery on processor board A09 may also have caused the same message, requiring extensive repairs.

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

(Pic1) Controller processor board

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

(Pic2) Wires on the board

(Pic3) Battery has been placed behind the fan

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.

--Floopy (talk) 05:09, 4 May 2019 (MST).