Mitsubishi Proj. model VS6043A (4 of them same strange problem)

I made a service call today to a bar where they have 15 of these sets throughout the building. There are 6 in a row on this one wall. The sets are fed from a 16 tap splitter fed from a distribution amplifier. The 16th position is terminated. I'll try to describe this symptom as best as I can. Three of the sets on this wall seem to have what I at first thought was symptoms that mimicked a signal ingress into a cable like from a loose fitting. The picture has small straight across horizontal lines that wave through it at varying rates. I checked all the fittings in the distribution and although many were loose tightening them did not improve the situation. I got to the back of one of the affected sets to check the fitting and it was tight. I substituted a new wire to this one set but it did not make any difference. I swapped cables in the splitter too. I also tried the alternate RF input but with the same result. I was starting to suspect tuner problems until my son switched one of the sets to line and we noted that the wavy lines were also present on the blue screen with no video input. So it does not seem to be an RF problem but it is affecting three of the sets on this one wall and one other in a different location in the building. Is anyone familiar witrh anything common on this set that sounds like the problem I'm having? It just seems odd that four sets are similarly affected. Thanks very much for any assistance. Lenny Stein, Barlen Electronics.

Reply to
captainvideo462002
Loading thread data ...

IIRC there are some 100 uF caps near a couple of 78XX series regulators. They're on the signal board and I think you can just about see them as soon as you take the back off.

They may check good or marginal on some ESR meters.

JURB

Reply to
ZZactly

Jurb I don't mean to sound stupid but what is "IIRC"? Are these caps in the LV power supply section because this does sort of look like a power supply ripple effect of some sort? Is this a common problem on these? The thing is if I can't fix these sets on site I won't have anyone to help me haul them back to the shop. And I'll probably be burned for the time i will invest in trying. Thanks very much. Lenny.

Reply to
captainvideo462002

Hi...

If I recall correctly, IIRC means If I Recall Correctly :)

Sorry, couldn't resist :)

Ken

Reply to
Ken Weitzel

Thanks I'll have to remember that one. My wife says I'm way too verbose. Thats when shes being nice. Lenny,

Reply to
captainvideo462002

Those capacitors fix 90% of the problems with those. It is strongly suggested you take along a good flashlight and esr meter to do a good check across all the boards paying special attention to the power supplies, scan circuits (H&V), and the video circuits for any signs of leaking capacitors or high esr ones.

It has been my experience on that series rptv with the regulators that I usually would find about 2 to 3 dozen capacitors clearly bad. I would take about 10 minutes visually going over each board and checking esr and would mark the top of any suspect capacitors with a permanent marker. Then I could make a list of the values needed and replace all of them at once. Total repair time per set of actually working on it, less than 2 hours. Number of call backs, ONE: the first one that I did not go over every board the first time.

Reply to
dkuhajda

I think Ken is right, IMO..

John

Reply to
John-Del

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.