QA BULLETINS (click here to return to List)

1. REPLACING PRINTLAMPS

Replacing old or failed printlamps should normally not require balancing the FIMES pcb. In fact if this is done, running a test and re-balancing the printer will be required. Printlamps should normally be replaced in a set of 4 so that lamp changes can be scheduled. Prior to insertion the contacts of each bulb should be sanded with 400 grit sandpaper to insure removal of any oxide buildup. This will help prolong the life of the lamp and the printlamp sockets.

When the new lamps are installed, perform an OSLV immediatly, as the computer still has the old value (2.55 if lamps were changed because of copy light low), which would be too high for new lamps. After a warm-up and burn-in time of about 10 to 15 minutes perform another OSLV.

Verification of the OTFI values (MTEST) will show whether the FIMES needs to be calibrated:

• If the ZERO values shown are within +/- .05d, calibration is adequate and printing can continue without balancing changes (no Test is needed).
• If the ZERO values for BLUE and/or RED are outside these values, adjust them but NOT the green channel (which avoids changing the printlamp intensity). A test must be made.
• If the ZERO value for GREEN is outside these values, adjust GREEN first an then BLUE and RED. A test must be made.

2. COPY LIGHT LOW

If copy light low is shown after a printlamp change, the Lamphouse and filter unit should be cleaned, as too much light may get lost prior to reaching the measuring cells. Maintenace should only re-calibrate after this has been assured.

3. LAMP AGING DURING PRODUCTION

During extended production there is the potential that the print lamp intensity may change due to aging of the lamps. This is, however, fully compensated by the filter unit logic that will automatically position the filters to compensate for any change in printlight. For this reason it should not be necessary to perform additional OSLVs during production. (In fact, a Test should be run after an OSLV, as the Lamp Intensity may have changed.)

4. CLEANING MAINTENANCE

The Lamphouse lenses and mirrors should be cleaned periodically to maintain acceptable printing speed and quality. Some dirt deposit may resist most cleaners. If a white haze is present that does not yield, vinegar may actually do the trick. Do not use abrasives on any of the mirror surfaces (first surface coatings of mirror or filters may scratch).

5. RECOMMENDED PRINTLAMPS

GRETAG recommends the use of PHILIPS brand lamps only. The following type is specified:

Philips # 6958
ANSI # EVC.FGX
24 Volts 250 Watts
Luminous flux 8400 lm
Rated avg. life 300 hrs.
Burning position: any

This page last modified: May 08, 1997
copyright FINISys Inc. 1997, author: R. Ganahl