Panel LCD Repair
The Panel is required to identify System Reference Codes (SRC) when the machine unexpectedly stops during IPL or in the middle of being used. A partly defective LCD prohibits clear readability and hence coming up with proper countermeasures.
The usual hints to disassemble the LCD and clean the elastomeric connector and related contacts with isopropyl alcohol did not suffice for me.
The original LCD is rather generic:
- 8 character positions, 1 line
- 14 pin data transmission
- HD44780 based
Mechanical attributes:
- 30×15 mm display canvas
- 58×32 mm circuit board size
- Background light pin spacing: 13 mm
The crucial point is the spacing between the LCD board and the panel board itself, so the LCD has the proper spacing to the front bezel. This greatly limits possibilities to adapt and reliably mount LCDs with different connectors.
The only (optically) matching LCD I have found is called O LCS082-3cbt; ST7066U-0B Controller in a Polish shop. This has two lines instead of one, though. Should not matter in practice, the lower line will most likely stay blank. I have not tested this!
Fortunately, I had a panel from another older AS/400 I scrapped before. So I desoldered the LCDs and soldered the good one in.