CurtPalme.com Home Theater Forum

[lostindiana]

Hello,

I have a Dwin HDP-500 and I am in the process of troubleshooting an issue and wondered if anyone had some input.
I currently am just trying to get the menu to appear and I am not having any luck so far.

I do have the remote and the projector is on standby when I apply power and the led turns solid green when I press power on the remote. I can hear a slight relay click and when I look inside the chassis I see the CRTs have a slight orange glow towards the ends of the tubes.

I attempt to press the menu button and nothing happens.

Do I need some sort of signal coming into the projector to even access the menu?? Or do you think my HV power module is toast?

Thanks for your help!

[lostindiana]

So far I have gone through the power supply and replaced my two main power filter capacitors since the old ones were bulging. I am getting a high voltage probe this next week so I will put to sleep any power supply issues.

I suspect there is a faulty component in the horizontal scan circuit so I will be testing those this next week when I get my huntron tracker.

I will keep this post up to date with progress and pictures so that other people might benefit from my efforts.

-Michael

[JayAllan]

Hey Lost,

If you don't have any luck try emailing DWIN in Burbank. I have a HD700, and when I had problems they were quick to get back to me. The menus in these are tricky and locking on to a signal can be a bitch. I still don't fully understand how to program the input blocks. I leave mine at 1080i and feed it from a DVDO VPH30. It has a great picture once you get it up and running!

Jay

[lostindiana]

Here is my progress on fixing my dwin hdp-500.


Current symptoms: When projector is powered on the back of the tubes glows light orange and the tubes to do come on.
The high voltage portion of the projector does not seem to be working.

Since dwin doesn't seem to keen on releasing their schematics I have to do a bit of troubleshooting in the dark.

I began with the low voltage power supply.

I noticed that the two input filter capacitors seemed a bit puffy so I replaced them.
I initially didn't have a capacitor ESR meter to fully check them but I soon remedied that.

The replacement of the capacitors did nothing to revive the supply.

I did some more research.

I read a forum post about someone with a hd-700 that was having almost identical issues with their projector.
(http://www.avsforum.com/avs-vb/archive/index.php/t-847091.html)

After reading this post I decided to concentrate on the main board to see if I could find my problem.



I removed the large main board and began a visual inspection of the board. I took the main board out and reflowed all the power transistor solder joints and tried to power on again. Nothing changed.




I pulled the board out and did a closer check on the bottom of the board. I noticed some dark areas on the board under transistors Q41 (A1406), Q40 (C3600), and Q42 (A1406).



I pulled out all of these transistors and checked them individually.

Q41 had a base to emitter short
Q40 was completely open
Q42 had a base to emitter open and base to collector short

at the time I also noticed a resistor next to them (R354) was discolored so I replaced it as well.

by this time I had received my capacitor esr meter and was able to pin point two capacitors that needed to be replaced.
C155 and C93

I also rigged up a light bulb in series with the main power supply so I would not blow any parts and could check for shorts.

After this effort, I attempted to power up the projector with the lightbulb trick and the projector stutters to start.
The relay clicks on, the light gets bright and then the relay clicks off. There is still no high voltage.

I again removed the main board and began the process of testing ever single power transistor and diode on the outer rim of the board. (U18, U17, U16, U15, Q19, Q18, Q17, Q20) (Q15, Q16) (Q8, Q12, Q11, Q10) (D13 Q7) I am still testing the rest of them now.

In the mean time I have been really listening to what the power supply sounds like and have noticed that one of the transformers makes a odd buzzing sound when the projector attempts to power on. (TR1). I tested this transformer with a shorted turns tester and it appears that one of the primary coils may have a short.



I may have to see if I can find another HDP-500 on the market or something since there are no available schematics out there and the high voltage block is filled with silicon.

I am back to looking at the power supply because of this noise and a heat mark on the connector going to the high voltage block.



I should also mention that I checked all the transistors on the power supply and all checked out good.


That is my current update and I will try to keep this thread more up to date as I continue to troubleshoot.

-CZ



I tested[/url]

[macgyver655]

Are you running that light bulb in place of a fuse?

[lostindiana]