The last of the backlight bulbs for my DIC burned out the other day so I took it out and replaced them with 74LLs. I put it all back together but now the display is glitchy. The backlight works ok, and the DIC itself seems to work ok (responds to button presses, shows doors open closed etc), but random items will flash or flicker. It did not do this before I changed the bulbs.

For example, while sitting in the parking lot with the key in "run" but the engine off, the big digits flicker on off randomly along with the "MP" in "MPG". The performance shift indicator also will flicker on and off (only when performance shift is enabled). Sometimes the car icon will disappear for a few seconds and them come back. I thought it might be a vibration issue or a loose connector, but wiggling the connector on the back, the wires inside, or tapping the display doesn't seem to make a difference.

I have a good electronics background working with SMT circuits boards and disassembled the unit with an ESD mat and wrist strap and I severely doubt I managed to zap it somehow. There don't appear to be any cold solder joints or lifted traces on either board.

I have searched around a little and found some information on the display digits flashing or the backlight flickering, but this is neither of those problems. The backlight is on solid and the DIC appears to be getting good info from the serial data line.

Is this something that can be fixed by me or a digital dash repair shop, or do I need to find a replacement somewhere?

Also, is the GT DIC different from the GTP? I'm guessing the GT one does NOT have the boost indicator but would otherwise work? I'm assuming I need a 98-2002 GTP version. I know that 97 will only work in a 97, but will a 2003 GTP DIC work in my 99?

Thanks in advance for any info