Heidelberg SM 102-5 CP2000 – Intermittent Controlled Stop Without Error / BLT Active H1 Yellow Goes OFF

[Viraj]

Heidelberg SM 102-5 CP2000 – Intermittent Controlled Stop Without Error / BLT Active H1 Yellow Goes OFF

Hi everyone,

We are troubleshooting an intermittent main-drive issue on a Heidelberg Speedmaster SM 102-5, Serial No. 545968, Year 2004, CP2000 and would appreciate advice from technicians experienced with BLT5 / MSK3 / SMM4 / UVM3 / KVT / TTK systems.

Original fault​

Initially, the press would power ON but would not enter running condition. We had S-BLT_CON / KVT related errors, and the MSK3 H2 red LED was flashing (error indication).

During troubleshooting:

• One damaged communication cable was found and repaired.
• Motor and main motor cable insulation were megger-tested and found OK.
• A fault was found in the SMM4/BLT circuit and one failed/loose electronic component was repaired/replaced.
• After this correction, the H2 red flashing disappeared and the machine started running.

Current problem​

Since then, the machine has developed a different intermittent condition:

• Machine enters RUN normally.
• Sometimes it runs continuously for hours/days.
• Sometimes it stops after a few units.
• The stop is controlled/smooth, not an emergency or sudden trip.
• No error message appears on CP2000.
• We have observed that MSK3 H1 yellow (BLT Active) turns OFF when the stopping condition occurs.
• The original H2 red flashing has never returned.

Work already carried out​

To eliminate possible causes we have:

• Replaced UVM3
• Repaired the SMM4/BLT circuit
• Checked BLT card and connectors
• Cleaned/reseated BLT electronics
• Checked main motor and motor cable insulation – OK
• Tested/changed CP2000 HDD/system
• Replaced all 4 IGBT modules – Infineon FF200R12KE3
• Replaced all 6 DC-link capacitors – 1800 µF / 400 VDC / 105°C
• Checked/reseated IGBT and gate connections

However, the same intermittent controlled stop still returns.

Main-drive values during normal running​

At one normal running condition we recorded approximately:

• Motor current: 35.2 A
• Motor temperature: 47°C
• Motor speed: 695 rpm
• DC intermediate circuit: 535.9 V
• Auxiliary voltage: 49 V
• Heatsink temperature: 26°C

So the 540 V DC bus and approximately 48 V auxiliary supply appear normal when the machine is running.

Main question​

Because H1 Yellow = BLT Active and it turns OFF during the stop, we are now trying to determine:

1. Is the central control/CP2000 intentionally removing the BLT enable command, or is BLT5 losing its READY/ACTIVE status internally?
2. Which CP2000 EAK / SAK / SEK input-output channels should we monitor to identify a momentary run permissive/safety signal loss?
3. Are there any known intermittent failures in SMM4, BLT5 driver/control circuitry, TTK-KVT interface, MSK3 supply/feedback, encoder/IDS or BLT backplane connections that can cause this symptom without leaving an error message?
4. Which signals/voltages would you recommend monitoring with an oscilloscope at the exact stopping moment?
5. Has anyone experienced a similar SM/CD102 CP2000 press where the machine runs normally for long periods and then performs a controlled stop with no operator error, while BLT Active goes OFF?

We are trying to identify and repair the exact root cause rather than replace the complete BLT assembly.

Any diagnostic sequence, CP2000 service-screen guidance, circuit information, or similar field experience would be greatly appreciated.

Thank you.