Question about 1990 GMC Sierra
Replaced the heater core and its not heating up?
The #1 cause for this ailment is low coolant. Be sure the air was burged from the system so that the heater core is not airlogged. #2 check for broken or disconnected vacuum lines under the hood. The heater air cond. system is dependent upon vacuum to actuate the dampers in the airbox. Rarer: check the heater hoses for restrictions, I have seen good looking hoses delaminate internally and pinch off the coolant flow. Somewhere between #1 and #2 I should mention the thermostat. But if the thermostat is at fault the temp guage will never reach the normal range.
First, my disclaimer:
I have a much older projector, but the way they are constructed hasn't changed a lot to my knowledge.
An excess of dust can shorten the life of electronics, it's a given. But the majority of these sets are allowed to collect dust for many years of operation before any problem occurs.
I sense that you may instead be asking about cleaning the lenses and mirror. Actually, the mirror, since it faces somewhat at a downward angle in these sets tends to stay clean. the lenses however, face upwards, and do get quite dusty, causing a blurry picture, with ghostly images on the screen at their worst.
To clean the lenses on most RCA sets I've seen, the screen must be removed. Allow the set to cool and voltages to dissipate for 30 minutes before beginning this process. There should be a removable panel beneath the screen, usually retained by screws on the backside at each end. REmoving the panel will expose the screws that keep the screen in place at the bottom. With the screen removed, the lenses (there are three) will be quite obvious. I clean mine with typical glass cleaner and SOFT paper towels. PAY ATTENTION not to allow any liquid to drip into the projector below or you may disable the projector unit possibly causing damage that must be repaired. If you are successful at the lens cleaning you will have restored the picture quality to like new.
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Posted on Dec 19, 2008
Confirm water ,coolant flow threw heater hoses if your correct . i would suspect you need thermostat
Posted on Dec 19, 2008
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Posted on Jan 02, 2017
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