Hitachi ED-A100 Lens door error and door won't close.

[unexus]

Fixed mine this way,

 

Removed broken gear. You now need to open the mirror manually. (no big deal)

Wired a LED bulb to the Motor connector in circuit board. see image.

rpaulson

@

ezworks dot net

 

 

[ATTACH=CONFIG]40425[/ATTACH]

Enjoy!

Hi,

 

I've got three of these that have failed. I replaced two last week with new Hitachi CP-AX2505 (no moving doors on this one). However, I would like to use the old ED-A100/A110's as mobile units by mounting on a trolley so they can be wheeled in as an emergency replacements. My thinking was that because I won't be using them in ceiling mode, the failed door opening mechanism won't be a problem. I can just open it manually. However, the projector stills fails to startup - I've got three of them and all of them do the same thing. I can hear the motor trying to open the door (even though it is already open) but it seems liek the sensor is not notcing that the door is open and so the projector switches off an flashes red. How do you defeat this mechanism?

[gkkes]

I have 5 which suffer the same fault. Does the LED work around fool the logic circuit on the other end of the hinge? This switch tells the state of the mirror.

 

[EngTech]

Having just read this thread and coming from an electrical / electronic engineering background, I'm a little sceptical and quite concerned regarding the suggestion of wiring an LED across the output terminals of the motor. Firstly I've not tried this so can not say if I actually works or not however an LED being a diode basically has the following electrical characteristics:-

 

Forward current flows as normal I.e. a direct short (slight volt drop but negligible)

 

Reverse current blocked I.e open circuit (if the diode is overloaded it will simply fail and short circuit)

 

So I can only assume the LED that is being suggested has an in built resistor to suit the 12v output. As far as I can tell from the schematics this projector (as with most consumer electronics) monitors the current of the output terminals infact the service manual states there are "over current" settings in the "factory" menu. But I don't see how this LED could trick the mirror motor logic, and position circuits.

 

As I've said I have not tried this hack, but the only conceivable logic behind it that I can think of is if the mirror motor endpoint switch (photographed by gkkes) is actually only used to check the mirror posistion then the current monitoring could possibly be used to confirm the motor has reached its hard endpoint I.e can't turn any more (large current increase).

 

I would be really interested to hear from any user who has tried this hack as I have a few of these projectors all of which work apart from the mirror.

Edited March 25, 2017 by EngTech

[unexus]

Hi EngTech,

 

I tried the LED hack on one of my projectors. It definitely stops the motor from turning but I still can't get the lamp to come on. I still get the Red warning light at the end of the startup routine.

 

"So I can only assume the LED that is being suggested has an in built resistor to suit the 12v output"... I'm not an electrical engineer so it's entirely possible that the LED I have used is not providing the required resistance.

 

If you don't mind giving me a quick lesson on how to identify the electrical resistance of my LED, I can have another go

[difinity]

I'm guessing the LED used was an uncommon 12v LED such 5mm Red LED | Maplin

Resistors are used with LEDs to limit current not drop voltage.

[unexus]

Thanks. I will scrape together £0.29p out of the budget and give it a go

[EngTech]

If I get some time later on this evening I'll drag one of the projectors out have a closer look at the schematics and have a probe around with my Fluke, simply dropping a diode across a 12v output doesn't sound like a great idea and may even damage the (BA6287F) motor driver.

 

 

If I get time I'll make some small PCBs that can simply plug in and bypass the motor and logic circuit completely, so put an end to those pesky gearbox problems!

Edited March 27, 2017 by EngTech

[EngTech]

I've managed to have a very quick look at the plausibility of the LED hack, the Kingbright 12V LED would not cause an issue when running the correct polarity, however this is where my concerns were originally aroused as the motor driver BA6287F reverses its polarity to close the mirror, and also to confirm the mirror position.

 

So in effect we would then be putting reverse ≤12v through the diode, Kingbrights datasheet states an absolute maximum reverse voltage of 5v.

 

 

This would suggest that even if the hack works it is a risky way to go as the LED will eventually break down and cook itself, possibly causing damage to the BA6287F motor driver.

Edited March 29, 2017 by EngTech

[TheInvisibleOne]

Has anyone got access to the 3D printer files and able to share? I believe there are around 5 different cogs within the motor assembly and if there are files for each, much appreciated. Thanks, Dave.

[EngTech]

Hi Dave, I've had a few of these gearboxes apart, and every gearbox has different broken or shredded gears. Ultimately it's a very poor design and not robust enough. The gears are injection moulded I'm not sure what material, I very much doubt that a 3D printer would be able to produce a gear that even comes close to handling the torque required as ultimately they need be substantially stronger than the originals.

 

To be honest the the gearboxes are so bad I wouldn't waste time with them.

 

I've managed to bypass a couple of the gearboxes by fitting a small PCB that I made, it means you have to open the mirror by hand but the projectors now work fine.

Edited May 18, 2017 by EngTech

[thegreatmagic]

i got a .stl file for that one also, send me a pm and I will mail it to you

Do you still have the .stl file? I just have the same issue, a broken clutch and no way to cange the whole unit, so I would give a try to 3d printing.

[thegreatmagic]

Hi Dave, I've had a few of these gearboxes apart, and every gearbox has different broken or shredded gears. Ultimately it's a very poor design and not robust enough. The gears are injection moulded I'm not sure what material, I very much doubt that a 3D printer would be able to produce a gear that even comes close to handling the torque required as ultimately they need be substantially stronger than the originals.

 

To be honest the the gearboxes are so bad I wouldn't waste time with them.

 

I've managed to bypass a couple of the gearboxes by fitting a small PCB that I made, it means you have to open the mirror by hand but the projectors now work fine.

 

Hi. Can you share the pcb design. I am having the same issue. Thanks.

[DAS]

Hi - many thanks for posting this positive Hitachi response dannyboy103. I tried but only managed to get an extension to 5 years which has no expired. We tired a local company which was cheaper but the projector then had an additional fault that time and had to go back to Equinox anyhow! Then we paid Equinox to repair 2 units at about £200! The trouble is the repair is with the same plastic cogs and the units are now going again!

 

So did you have an extended NBD cover in place and they extended it to cover this specific problem indefinitely

or was the extension from std warranty to NBD for this problem?

Just trying to understand if i can try and fight for the same now...

We cannot afford to replace these units and I know the head wants to jump straight to Activpanel or something similar if and when we do get any money.

 

Many thanks

Edited September 26, 2018 by DAS

[DAS]

Hi - many thanks for posting this positive Hitachi response dannyboy103. I tried but only managed to get an extension to 5 years which has no expired. We tired a local company which was cheaper but the projector then had an additional fault that time and had to go back to Equinox anyhow! Then we paid Equinox to repair 2 units at about £200! The trouble is the repair is with the same plastic cogs and the units are now going again!

So did you have an extended NBD cover in place and they extended it to cover this specific problem indefinitely

or was the extension from std warranty to NBD for this problem?

Just trying to understand if i can try and fight for the same now...

We cannot afford to replace these units and I know the head wants to jump straight to Activpanel or something similar if and when we do get any money.

Many thanks

[StevieM]

@DAS - Once the 5 year extension has passed, you will no longer get a replacement projector. However, in the past, I have simply emailed [email protected] to inform them of the problem and they have sent a replacement mirror motor free of charge. It's a fiddly job, but there are videos on YouTube that show you how to fit it. It's been a couple of years since I needed to replace any parts (cue them all failing in the next fortnight!), so I don't know if they will still have the part available, but it's worth a try.

[mfarley581]

We had a similar problem and have installed a small motor. It works both ways. It sounds at the start and when the door is supposed to open and close. All is well and our projector is working again!

 

Thanks for this thread which pointed me in the right direction.

 

 

[DrBeaker]

It's a known issue with these ones. Once place we had some replaced under the extended warranty Hitachi offered (once they sort-of admitted it was a manufacturing fault) but after that time had passed, it was our problem to solve. At that point the projectors were knackered anyway despite new bulbs, so we just replaced them. They'd had about 6-7x years of service then, so we'd gotten our money's worth.

[DavR]

Old thread I know, but just sharing an update.

 

We've just had this fault on an 8 year old Hitachi ED-A111. I've read this thread with interest, and commend the efforts of those who have 3D printed replacement cogs!

 

I emailed Hitachi tech services, who have said they're no longer handing out free motor assemblies.

 

If we had more than a couple of these I might argue the toss, but I've found replacements for £75 from AV Partsmaster.

[StevieM]

Thanks for the heads-up.

 

It's fair-do's though, as the projectors have been out of production for a LONG time. I'm surprised they've supported it this long.

 

We've had ours since 2009/10 and I've already warned the powers that be that we should be looking at replacing at least some of them. I just hope that they have allocated money in this year's budget...

[DavR]

These are definitely end of life now.... our two units have only survived this long because they're in break out areas, so aren't used as often.

 

I can stomach a few £75 repairs, then we'll have to see where we go if they fail again after that. I haven't budgeted for replacements this year.

[DrBeaker]

Poor planning from SLT and management though, not planning to replace kit once it's reached the end of it's useful life.

[Samdeluxjones]

I have just stripped mine down and found the cracked clutch cog.

 

I have ordered the replacement from ebay which claims to be stronger, https://www.ebay.co.uk/itm/STRONGER-Gear-Repair-Kit-HITACHI-GP00911-GP00912-GP00913-Mirror-Motor-projector-/232827853057

 

I tried super gluing and running a thin strip of tape around the outside of the cog which worked for 3-4 open/close attempts before failing again.

 

I have also ordered a new lamp so I better get this one fixed or I'm out 150 quid..

[DavR]

I did see the eBay offer, but baulked at paying £25 for a nonstandard plastic cog. Do report back on your experience!

 

I took delivery of a replacement motor assembly today, so that'll be a fun job in the holidays stripping the unit and changing that.

[DrBeaker]

I did see the eBay offer, but baulked at paying £25 for a nonstandard plastic cog. Do report back on your experience!

 

I took delivery of a replacement motor assembly today, so that'll be a fun job in the holidays stripping the unit and changing that.

 

How old is that projector though now? Tech-to-tech how can you justify the time and labour involved in fixing such an old bit of kit though?

[DavR]

How old is that projector though now? Tech-to-tech how can you justify the time and labour involved in fixing such an old bit of kit though?

 

We have two, both eight years old. They're in seldom used areas though, so they've not actually done much mileage.

 

Potentially they may stop using these areas altogether, so I'm loathe to spend anything beyond repairs money on them right now.