1. Home
  2. Electronics Repair
  3. Epson EMP-7600 Projector

Epson EMP-7600 Projector

A projector I bought used for my son seems to work fine for about 40 minutes then the "lamp indicator" blinks red and the projector lamp turns off. User manual says replace bulb because it has reached its end of life. The hours indicated 611 hours which I reset with no change in operation. I replaced the bulb with a new one and the same thing happens. From what I have read (wikipedia) the life of the bulb has to do with the voltage required to drive it. It becomes higher as life goes on. I can imagine some sort of circuit to sense either voltage or current on the powersupply module and inform the processor when some limit is reached. The bulb type is ELPLP12. Does anyone have any information on this or any schematic documentation which might help me troubleshoot it. I do have experience with high voltage supplies etc.

Reply to
dodger741
Loading thread data ...

There may be problems in the power supply or with the cooling of the system. The service people would change the power supply to start, and take internal temperature readings.

Most of the manufactures of these units will not sell spare parts, or any service manuals to end users. To service this unit is specialized work.

Research for the service rep in your area. Take the unit in for an estimate. It is possible that the repair may be worth the cost.

Jerry G. =3D=3D=3D=3D=3D=3D

Reply to
Jerry G.

I would start by checking electrolytic capacitors on the lamp ballast, and in the power supply for the whole unit. If you reset the bulb timer and it still shuts down, then something is wrong with it.

Reply to
James Sweet

Well I took it apart and found several things. First of all a lot of tightly packed boards etc - what a nightmare to work on. The ballast board is very compact with transformers and igniter module, and 2 daughter boards soldered in. I found the current sensing resisters on the board (10ea 1.0ohm resisters in parallel) and will measure the current shortly. I found a similiar manual online (EMP 7700) which had block diagrams and some details about the power supply. They talked about a 28 pin connector which carries the supply voltages to the main board. I have a 28 pin connector and all my supply voltages matched this manual except pin 14 which is listed as 12 volts and I measure 0 (not even a hint of voltage even looking with a scope). There is a wire in the connector so it is for something. The other item was a small fan (2.5") which blows on the low voltage board and also the HV ballast board. The fan doesn't come on. It is a 12 volt fan which is connected to the LV supply board. The voltage supplied at the connector is 8 volts with no ripple. I plugged the fan into 12 volts and it doesn't work. I thought this might be it so I rigged up another fan to blow on the boards and plugged the unit in. The light came on but went out in half the time it used to (25min). I am just turning the unit on (blue screen) with no inputs). Maybe with the case off etc the air flow is not working correctly which caused this failure. Seems like I need to disassemble the whole thing to get to the LV supply board to investigate the 8v fan drive for the 12v fan. Any more thoughts??

Reply to
dodger741

The 8V to the fan may be by design, to run it at a slower quieter speed. If the fan is bad, fix/replace it first. The circuit may detect the current draw or RPM of the fan, is it a 3 wire type with a tach signal?

Reply to
James Sweet

Just a follow-up. There are several other fans in this unit. I had suspected a thermistor on the lamp as the culprit but as I tested I found that when this over-temp condition is triggered, a different failure mode occurs. Also the fans speed up so I suspect the 8v is a variable voltage/speed fan as James suggested. The other thing I discovered is that it does make a diffference if you don't have a changing presentation on the screen as it does turn-off after a while with no changing input. In the end, I replaced the fan and it seems to be working correctly now. Thanks to all who commented and made suggestions.

Reply to
dodger741

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.