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BenQ projector lens MP512ST

Who can help me with the projector lens MP512ST BenQ projector. I need to replace the lens as the current lens had an accident.

⟐ Edited agosto 06, 2015 at 11:59 GMT-7

⟐ Answered enero 05, 2026 at 8:41 GMT-7

⟐ Answered julio 01, 2019 at 18:43 GMT-7

⟐ Answered marzo 02, 2024 at 14:15 GMT-7

⟐ Edited by author mayo 05, 2025 at 9:49 GMT-7

⟐ Commented abril 15, 2022 at 5:39 GMT-7

⟐ Commented febrero 03, 2020 at 6:33 GMT-7

Inserting the power cable, you can hear a whine from the power supply as it powers up for about 10 seconds before that is replaced with a higher pitched whine from then on. Power/status LED’s don’t light up, the fans don’t run, the lamp does not power up.

When I first received this projector, I stripped it down to take a quick look and put it all back together, and it turned on! It stayed working for a few days until one day during operation it died again.

What I have tried so far:

• I have replaced the power supply entirely as I believed it was not providing power properly to the board (replacement power supply shows exact same behaviour as previous one)
• Searched the processor board over and over again for obvious bad caps with a multi-meter (I am an absolute novice at this, so it’s possible that the board is shorting or something and I just can’t find out where). Part of me wants to doubt it’s the processor board simply because it was working totally fine just a few days ago

What is most likely to be the problem? I’m most confused because after my first strip down the projector started working again totally fine. I should mention that when it died again after my first strip down I was moving the projector and believe the power cord shifted slightly, which is when it died.

Note: I have tried powering the projector on with the lamp cover on etc… as I know that the projector won’t power on without the cover. The fans/status lights should power on whether or not the lamp cover is attached.

Here’s a video of me inserting the power cable, if you turn your volume all the way up you can hear the power supply

⟐ Commented agosto 18, 2022 at 1:57 GMT-7

Thank you! :-)

⟐ Answer accepted agosto 31, 2020 at 7:17 GMT-7

⟐ Commented septiembre 16, 2024 at 7:17 GMT-7

Blue power light when plugged in.

Press power button, blue power light stays on, blue status light starts blinking. Fan spins up normally, but bulb never lights up. Status light keeps blinking for about two minutes and then projector turns off, blue power light still lit. No reaction from any button press after initial power button press.

Have tried changing the bulb, no difference. Have had it open, removed and mounted the ballast board in another known good EB-475 I have, as they are practically the same. Ballast works fine. Power boards not identical, so can't try exchanging them.

I have done some more Research. All thermistors (temperature sensors) are Reading about the same resistance, 11.5k ohms. The Power supply seems to work properly, no bad caps or visible damage. Output voltage to the mainboard seems to work properly and Readings are consistent. The fans turn on and no fault lights when Power button pressed. Input voltage to ballast is 373V DC, which seems right. Tried changing ballast also the other way round from my other known good similar projector, and there is no change starting it With a known good ballast. Tried putting the bulb into the other projector, starts properly and lights up.

I’m really running out of ideas.

Had it been the safety switch, it should have cut all Power, not allowing the projector to start at all.

There is no voltage going to the bulb, so there is something in the Logic not letting it start.

I can not stop the projector again by pressing Power off two times, which would be the normal routine, which leads me to think the machine doesn’t start properly. Any ideas? Hard reset routines or computer diagnosis port would be helpful.

⟐ Commented mayo 30, 2022 at 3:35 GMT-7

It then shut itself down and the lamp cover indicator lights up. No warning of any kind before this happened.

I have removed the lamp, but it dose not look as if it has blown! How can you tell?

Could it be the lamp is OK and its another problem?

⟐ Commented marzo 06, 2022 at 23:24 GMT-7

Ok So there is a SOLUTION. If you want to fix your little projector you need to order the part below or one of the same dimensions. This part is a little bit thicker than the stock one but if you carefully press it in or widen the side guides a little bit it will fit and work perfectly. I ordered two so I would have a back up. It did take over a month for the part to come. I wrote it off because they never sent an email to say it had shipped, but eventually it did show up. That's ordering Chinese parts for you. Good Luck! Haribol

https://www.aliexpress.com/item/40006995...

⟐ Answered julio 12, 2023 at 16:17 GMT-7

⟐ Answer deleted diciembre 10, 2020 at 13:08 GMT-7

I’m in the process of fixing my Epson EB-W130 projector.

The projector doesn’t turn on or show any indication of powering up (power buttons do nothing and no LEDs light up when power is applied).

I’ve been trying to locate the service manual for it. (Note this is different to the user manual).

So far google searches have only returned the user manual.

Does someone know where I can find it? Or perhaps point me in the right direction to obtain it please?

Cheers,

James

Currently my investigations point to the main power supply (main PSU).

I’ve found:

• 2 fuses - all intact still.
• 1 thermal fuse - which is operating correctly.
• 240V AC (Australian mains) is measured on the main PSU board successfully.
• Probing the main PSU shows that it’s output to the processor PCB is 0V DC (expecting 17V DC according to the silkscreen on the main PSU board). I’ve even hooked up the oscilloscope to see what the main PSU does when power is applied. Nothing, there’s a small flinch in the voltage level but nothing to really indicate that the power supply powered up and had it’s output disabled by the processor board. There’s not even any activity on the optocouplers that pass control signals from the processor board to the primary side of the main PSU.
• Disconnected the main PSU from the processor board. I read 10 V DC on the output (expecting 17V DC according to the silkscreen). The oscilloscope shows a very clean 10 V DC signal.
• I try connecting the power supply to the processor board again, this time with the optocoupler signals disconnected to make sure there’s no ‘kill’ signal being sent to the main PSU. Power on, and the supply’s output measures in at 0 VDC again.

Perhaps the main PSU is not working properly (indicated by 10VDC being measured instead of 17VDC). It could therefore be struggling to source enough power for the processor board to boot up?

I’ve started reverse engineering the power supply a little to double check that the PSU IC, transistors and other components are working/biased correctly. (This is where I was hoping for a service manual to help me along). Nonetheless I will continue investigating.

At this stage I’m not sure if I can trust the 17V DC marked on the main PSU’s silkscreen. I have thought of powering the processor board using my bench PSU - I just don’t want to risk damaging the processor board until I’ve investigated the input range it can handle. I see switching regulators, so perhaps it has some tolerance to input voltage. My thought is - if it powers up from the bench supply and provides some activity on the status LED’s then that’ll add evidence to the problem existing at the main PSU.

⟐ Commented agosto 21, 2025 at 23:26 GMT-7

⟐ Answered mayo 20, 2024 at 1:02 GMT-7

⟐ Answer deleted abril 12, 2022 at 13:47 GMT-7

⟐ Answer accepted septiembre 11, 2020 at 20:13 GMT-7

⟐ Answered agosto 29, 2015 at 20:38 GMT-7