This set has no blue to the picture. I did some checking and found that there is 225V on the collector of Q656 and it runs cold, while the other two outputs run around 150V. (I'm assuming that Q656 is the blue output). The other seemingly abnormal thing is that there appears to be no signal on the base of Q653, while the other two transistors which again I'm assuming are the red and green drivers have signal. (And again since I have no schematic I'm making an assumption that Q653 is the blue driver). So I'm going to have to look further however the demodulated video signals seem to come from a vertically mounted board which because of its placement will be almost impossible to troubleshoot without a schematic or at least further help. Can anyone please assist me with this set? Thanks very much for any help. Lenny Stein, Barlen Electronics.
Follow your wiring from the CRT board down to the chassis and look for a small IC near there. It's only a simple 8 or 10 pin single row IC. Forget the number and not near the shop now, but replacing the chip should restore the blue, although chances are the problem may return again in a few months.
IC6F01, AN5862K, IIRC. The problem should not return if you add the diode modification as per the Mitsubishi service bulletin. I have never had a repeat repair on one of these, using either the chips supplied by Mitsubishi or from other vendors.
leonard, can you email me a copy of this service bulletin. i have a mits 35707 with no green and in termitent loss of blue once loss of red with only blue then screen went black . are all ic's an5862k and what is the diode? 125? and where to put it? sam
Just do a google search for the info. Help yourself before expecting techs to waste their time doing your research for you. The info has been posted previously in at least two technicians forums publicly available on the internet referenced to the model number. It has likely been posted on this group, too. Come on, guys, you didn't even need to ask the question if you had looked. I pointed you in the right direction and with the info I gave you probably would narrow the search to the specific answer. I don't mind helping, but gee whiz, do I have to go look it up for you?
Isn't this kind of research routine and trivial for techs these days? I spend a good hour of my day doing research to make my shop run more efficiently and find fixes just like this all the time. Am I the oddball? If I don't find a fix in the databases I have, the forums that I search, or from the manufacturer, I always at least google it before expecting others to look it up for me. Only after doing the research myself do I post a question on the newsgroups, forums, or listserves.
I go out of my way for other techs all the time, but I know them and know that they will reciprocate, that they have likely done their homework first, and that they are qualified to use the info properly. I am not going to go very far out of my way for someone who does not identify who they are and the company that they work for. I will give advice from memory to anyone, but if you want to stay anonymous don't expect much more.
Leonard, I am not anonymous. I gave my name and company name in the very first post. If YOU had taken the the time to read it before you had written your unfortunate tirade you might have noticed that. I've been a participant in this NG for many years. Just for the record most of us are running shops here, so you are not in the minority. What you are alone in however is being a person who instead of wanting to help a fellow tech, you would rather insult their intellegence. I help people too when I have the answer to a question. I don't dangle a carrot in front of their nose with half a story. Just how many times have you seen me ask for assistance in this column this year anyway? You would think my sole mission in life was to waste your precious time. It just so happens, and just for your information I did do an online search for this problem, and gee whiz but I'm so sorry that I didn't find the answer, and subsequently put you to all this trouble sir. I really wouldn't have asked in the first place if I really didn't need the help, but you have my sincere appologies for bothering you. Please, don't bother to "help" me any more. Lenny Stein, Barlen Electronics.
The point of my "tirade" was obviously missed. That is, part of the job of any decent tech these days should be to do internet research. Asking questions is not a problem and I do not have a problem answering them and helping other techs, even consumers, as my postings demonstrate. I would not even post a question, however, without doing the basic searching first. I have more respect for YOUR time than that, and am more professional than to expect others to do my work for me. It is not as if the info was not available to you.
A few things to consider:
I did not dangle a carrot. I gave the info that there was a mod and the chip description from memory and assumed that you could do a little simple searching for the details, like I would have to do if I needed the same info. Your last message was just signed Lenny, and I did not recognize you as a tech. I responded to someone else's post, if YOU would notice from the reply, and do not make a practice of going back to the original post when I have something to contribute that does not require it. I read the usenet groups intermittently exactly because there are more than just techs here. I don't recall every mod, nor keep the info at hand at home. A quick google search shows the info is available on the following: network54.com techassist listserve wa6ati.com euras.com All but the last one have archives that are searchable to some degree for free. Techassist has a great site with tips and other stuff available for a pittance in a much more organized form than the freelists archives, but the info comes up in a google search on this matter. Searching google with "mitsubishi cs35607" gets this from techassist via the freelist archives with just a few links checked:
replace ic6f01 part no.264p045040 and install a diode1s2471m with the anode connected to the anode of d6xa1 and the cathode connected to the cathode of d6f04
I don't think pointing out that you could have done that 2 minutes of looking yourself is insulting your intelligence. It just points out that you are either lazy or inconsiderate. Now go fix the set with the info that I found FOR YOU.
Leonard- I looked at the siites you supplied and did find the WA6 one very helpful, and not too hard to navigate. I'm not lazy, I'm busy like the rest of us, but I'm just surprised that I never ran into that one before. In any case in spite of the fact that I asked you not to help me any more, you did and I do appreciate it. Lenny Stein, Barlen Electronics.