Beolab Penta MK3 displays dead

in BeoLab · Aug 23, 2026 06:18 GMT

Epilogue. The zener and transistor in the BC were tested and found good. They were placed back and lo and behold! The display in the Penta worked! There was no difference in the data that came over the Beolink as seen on…

Beolab Penta MK3 displays dead

in BeoLab · Aug 5, 2026 12:57 GMT

More red herrings. I thought the jitter was an important clue so I wrote code (attached) to produce a jittery command based on a Saleae recording. The displays on my workbench happily displayed the data from the command.…

Beolab Penta MK3 displays dead

in BeoLab · Aug 3, 2026 19:10 GMT

Well, I thought I was on to something. I changed the oscillator timing on my PIC Beo command generator so the timing got slower. I started at 1.80 ms (spec: 1.56 ms) and did not get a display. At 1.62 ms the display was …

Beolab Penta MK3 displays dead

in BeoLab · Aug 3, 2026 05:54 GMT

With the help of a cheapo logic analyzer I finally managed to get readings from the affected Beocenter (which happens to be a 9500). It only sends single bursts whereas the display only reacts on two bursts. The protocol…

Beolab Penta MK3 displays dead

in BeoLab · Jul 21, 2026 21:59 GMT

The chance of all four displays sharing the same failure are infinitesimal. With the help of a Beocenter 2k5 I loaned from a friend I fed one display a beolink databurst and lo and behold the correct text appeared on the…

Beolab Penta MK3 displays dead

in BeoLab · Jul 10, 2026 15:00 GMT

I just realized something. The AUDIO/!VIDEO input is HIGH to unblank the display. When LOW in case of home theater it blanks the display but if the input has gone phut and always reads LOW for the firmware inside the 80C…

Beolab Penta MK3 displays dead

in BeoLab · Jul 9, 2026 21:15 GMT

Veteran electronics engineer but first time poster here, hailing from Amsterdam. A good friend and B&O fanatic has four Penta mk3 displays that are all four dead. He sent them to me and because I have no B&O equipment I …