# CP-RS56 "Check Air Flow"



## xq1

I have a Hitachi CP-RS56 LCD Projector.

Check Air Flow is being displayed in the middle of the picture.

I have blown out the filter. I took the unit apart and blew out everything on the inside. Nothing looked very dirty.

From some reading it looks like the thermal sensor may also cause this problem.

Can anyone send me instructions as to where the thermal sensor is and how to replace it?

Can the thermal sensor be tested?

Thanx alot!


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## dyohn

Per page 47 of your owner's manual, if you've replaced the air filter the next step is to manually set the fan speed to HIGH in the service menu. You may also want to reset the projector's processor, per the instructions on page 50. If this does not help it may be time for a trip to your dealer for service.


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## xq1

Hi,

Thank you for your info.

I have already done what you suggested.

The projector is at a church and the local service centre wants $180 to just look at it.

I am a electronics engineer so I thought I would take a stab at this.

I am thinking that the thermal sensor seems like the problem.

My problem is that I do not know where the thermal sensor is or looks like as I have never seen the insides of LCD projector before.

I was hoping that someone would have a copy of the service manual or point me on how to service the thermal sensor.

Is this a forum for getting into the technical depth that I am asking for?

If not is there another forum that I should pose the query to?

Thanx!


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## dyohn

You're only likely to get that sort of technical info from someone who also happens to own it or who works in a shop servicing them unfortunately. The thermal switch may be embedded in a printed circuit board and not replaceable.

As an aside, $180 for a service call on a $1500 projector that has been out of production since 2007 does not sound all that high to me and is a lot lower cost than replacing it...


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## lcaillo

Thermal sensors in projectors are usually discrete parts on the lamp housing or nearby.


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## tonyvdb

Would the thermal sensor not shut it down? I suspect an airflow switch is faulty. That would be located somewhere in the airflow path near the filter.


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## lcaillo

It depends on the design. No way to know without some documentation from the vendor.

What is an airflow switch? Never seen one in a projector.


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## tonyvdb

lcaillo said:


> What is an airflow switch? Never seen one in a projector.


usually its a micro switch with a small paddle that if the airflow is present it makes the switch. Its possible that one is not present in projectors but who knows.


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## lcaillo

All of the airflow warnings that I have seen have been triggered by temperature.


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## xq1

Hi Everyone,

Thank you for your time to this issue.

I eventually found a service manual on line.

I tried to upload the manual but it was 6 mb.

Does some know how to post a 6 mB file for others to use in the forum or that not the purpose of this forum?

Thanx again everyone!

-John


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## dyohn

If the manual is on line, just post a link to it for those who may want it.


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