Hi all,
First time post, so admins please accept my apologies if this is a) already covered and I just haven’t managed to find it, or b) if I’ve put it in the wrong place.
I’ve got a BQ Hephestos Prusa i3 printer that’s about 3 years old, now running Repetier firmware. It’s equipped with a mk2(a?) heated bed and a 203W Xbox 360 power supply, again both supplied by BQ as part of the original kit. It’s been used regularly, but not intensively, for most of its life, without issue until yesterday when the PSU started showing a fault light when powering the heated bed. The first time it happened it was 5 minutes into a job, but now it cuts out when the bed approaches ~50°C.
I’ve tried heating the extruder on its own, and it can reach and hold 200°C without problem. Likewise running the print job on a dry run (I.e. without extruding or heating the bed) seems to be fine. However heating the bed, either through a GCODE file or a command from Pronterface causes it to cut out.
So far I’ve checked the connections and resistance of the bed and cables (~1.2 ohms), the functioning of the thermistor (good compared to an IR thermometer), the output voltages of the disconnected power supply (~12V at the RAMPS connector) and the continuity of the RAMPS fuses (ok), and nothing appears to be amiss. There’s been no unusual smells, smoke or obvious signs of failure from the electronics, and everything otherwise appears to be functioning normally.
I know the Xbox power supply is at its limits for this setup, but historically it hasn’t given me any problems. Is this just indicative of an ageing power supply giving up the ghost, or is there something potentially wrong elsewhere? Are there any other checks I can do to try and identify the fault before I start buying new power supplies, heated beds etc? Any advice gratefully received!
Regards,
James
Edited 1 time(s). Last edit at 04/02/2018 07:35PM by TheDarkGekko.