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Printer won't power on, tried everything

By Mugsy ยท 103 replies
Jul 5, 2011
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  1. Margaret42

    Margaret42 TS Rookie

    Have 'no power' problem with Canon MG5350. Phoned Canon service who told me this wasn't a usual problem... looks to me as if it is! Removed and replaced the white cable holder; printer came on! But with a message saying a problem, to disconnect and contact service centre. Disconnected and it won't come on again. I won't be contacting their service centre and will go for new (I haven't the time to take the machine to pieces)... but a big thank you to everyone on the forum... a great help to someone who has never tried taking a printer to pieces before! Now I need some advice on a new one... will look on the forum.
  2. pde14

    pde14 TS Rookie

    Same no-power problem as others, on a Canon iP4500.

    Removing and reseating white connector on PSU made no difference. Tried this several times.

    Applied +5V to yellow PSU cable. PSU voltages good but still will not switch on.

    Reassembled and press power button one more time. Printer powers on OK!
  3. pstspot

    pstspot TS Rookie

    Hi: just found this thread and I think I undersytnd why some people get differet voltage readings from the power module, and also why disconnecing it and reconnecting it sometimes cures the "won't start" issue. (I'm an electrical engineer.)

    The power module contains capacitors. Capacitors can/will retain a charge unless an external resistive load drains it away. If external logic connected to a power supply with enough capacitance goes into an undefined or lockup state, the charge of the capacitors will maintain that condition even after the mains power is disconnected. Modern logic circuits have VERY low internal resistance, and some components like static RAM don't depend on an external voltage to maintain their memory.

    Canon printers with detachable power supplies have no isolation beyween the mains power and the logic circuitry, and on US models, no chassic ground (Canadian models require a grounding connection). That makes their logic circuits susceptible to static discharges and to high ampitude power line voltage spikes of short duration. Knowing thism I connect all my equipment through old school Isobars, which do a good job except for the worst case situtauion: extreme high voltage but low energy line spikes.

    I've never had a Canon printer that failed during humid weather except once immediately after a severe thunderstorm. The only lockup I experienced, happened recently when it was cold and very dry. Disconnecting the power module from the chassis and putting both in a high humidity environment for a few hours allowed the internal logic to reset and the capacitors of the power modue to bleed down. After letting both dry out, and resasembling, the printer worked like new.

    As far as seeing or not seeing voltages on the connecting conductors between power module and chassis, that would depend on the particular module. A newest generation power modules have some basic logic to limit power consumption when off. Without that logic they would draw current and more current continuously whether or not the always-connected load was "on". The Canon module supplies only one very low amperage output voltage until the load need to draw more power. In Canon printers, the printers sends the power module a wakeup signal telling the power module to provide more current and possibly use other conductors to provides other voltages.

    A lot of the vilnerabiolity pf Canon and other appliances to static could be simply elimniated by mandating that grounded power supplies with some high frequncy line noise suppression be provided. That consumers accept logic controlled appliances that have no integral protection from the power grid is due to ignorance encouraged by appliance manufactures and makers of "surge protectors", because both groups benefit from appliance failures due to line issues. Adding individual protection to all equipment when built would increase the unit cost by <5USD and decrease frequency of failure to that of the mechanical components, typically a factor of 3 or more.

    BTW, +95% of all surge protectors are ineffective against high voltage low current spikes, and/or have "warranties" that are cost prohibitive and/or impractical to excerize.
  4. Lectricuted

    Lectricuted TS Rookie

    6.5 years later and Timroperco's post is still pulling em back from the dead! Cannon MX350 powered up after power bump killed it. Simple disconnnect and reconnect.

    Thank you sir, your a gentleman and a scholar.

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