Magnavox

[mav6759]

Re: Magnavox

Ok, I had the TV looked at, at local repair shop here in Atlanta. I was told it was the Y board, The guy that I brought the board from told me that he checked the board and everything was ok. I took the back off the Tv and everything looks good. I just hope that the repair shop here told me the truth. If not, we are going to have a little talk. Now I'm hearing all the clicks that truns on the Tv, and then clicks that truns off the Tv. I would think that would be more of the power suppy. But sinc I'm not a Tv repairman, I'm going to trust there judgement, I should get that new board tomorrow, I guss my question is, is there anything I'm missing,,

[PlainBill]

Re: Magnavox

For your information: http://cgi.ebay.com/PHILIPS-MAGNAVOX...-/130391338223

PlainBill

[mav6759]

Re: Magnavox

ok, I clicked on the link and called the guy that is selling the repair kit. Really,
nice guy, know his Tv's. He mentioned to me that if the Tv comes on, it is not the power supply, it the either the main Y board or one of Y buffer boards. He's selling a kits that repairs the power supply. So, I am still waiting for the main Y board to arrive. I thought it would be here from since i ordered it last Sat. If what I understand, these Y main boards are very hard to fine.

[mav6759]

Re: Magnavox

I found out it was not the main Y buffer board as mentioned before. I found a board call the scaler board that had either a blown cap, resistor or transistor. I can't tell what is it, because its blown so bad. I'm try to inclued a piture of the blown part, I hope it works. The picture shows a good board, the part that is blown has a red square box around it. The number next to the blown part is 72U4, have no idea what this is. The model number is a magnavox 42MF231D/17. Does anyone know where I can find a schematics for this board. I believe I can go to radio shack and get this part. If you are having the same problem, please check your scaler board.

[PlainBill]

Re: Magnavox

I found out it was not the main Y buffer board as mentioned before. I found a board call the scaler board that had either a blown cap, resistor or transistor. I can't tell what is it, because its blown so bad. I'm try to inclued a piture of the blown part, I hope it works. The picture shows a good board, the part that is blown has a red square box around it. The number next to the blown part is 72U4, have no idea what this is. The model number is a magnavox 42MF231D/17. Does anyone know where I can find a schematics for this board. I believe I can go to radio shack and get this part. If you are having the same problem, please check your scaler board.

What is your day job? Are you a tow truck driver, a mortgage broker, or a bill collector? What on earth possessed you to post a 900K .bmp file you found on the internet rather than an actual picture of your board?

Search for 42MF231D/17 schematic (don't use Service Manual, that will give too many false hits). If by any chance you find a free service manual, download it and look it up. Due to crowded circuit boards, Philips uses component identifiers. Tables in the service manuals cross reference to the actual part number, the Philips part number, the schematic location, and the physical location on the circuit board. In Philips / Magnavox terminology, the board is called the Small Signal Board. That particular section appears to be in the DC / DC converter. The fact that it is burned would indicate there are other shorted components.

HOWEVER, that is pretty pointless. The fact that you even contemplate buying parts from Radio Shack shows how inept you are.

PlainBill

[mav6759]

Re: Magnavox

OK, I have a question, I had the Tv looked at for a second time. From what the repair shop told me, the Tv was getting the 5v at startup that it needed to power on. All the power supplies, Y board, X board, Buffer boards (upper and lower) Z board all checked out. Matter of fact we had 5v throughout the set. From what the repair guy told me, he see's no reason why the Tv is power cycling off. After a little more investigating, we saw a burnt IC on the Main Tuner board. My question is can this board cause the Tv to power cycle on and off.

[PlainBill]

Re: Magnavox

OK, I have a question, I had the Tv looked at for a second time. From what the repair shop told me, the Tv was getting the 5v at startup that it needed to power on. All the power supplies, Y board, X board, Buffer boards (upper and lower) Z board all checked out. Matter of fact we had 5v throughout the set. From what the repair guy told me, he see's no reason why the Tv is power cycling off. After a little more investigating, we saw a burnt IC on the Main Tuner board. My question is can this board cause the Tv to power cycle on and off.

Yes. I have said this repeatedly, study the service manuals. I have been unable to find one for that set at any of the free sites, but they seem to be available from the pay sites.

That board contains a DC-DC converter which powers the signal processors, the input selectors, the on screen display, the scalar, and every control function for the TV.

When the TV is plugged in, the Standby processor starts up, performs a self test, then waits for someone to hit the power button. Once the power button is pressed, it closes the main power relay. At that point it start checking the various outputs of the main power supply and DC-DC converter. These include 5.1, 3.3, 2.5, 1.25, and 12 volts. If any of them are out of spec, it shuts down the main power supply. On a Philips TV it also flashes a red error LED in a pattern that allows you to identify the exact error.

Again, that burnt component is in the DC-DC converter area. IF, for example, the 2.5 volt supply is missing or reads too low, you very well could get snow on the screen until the standby processor turns off the main power supply.

PlainBill

[mav6759]

Re: Magnavox

Ok, I got he new video board today, I installed it and now I get nothing. No power cycling, no lights nothing. When I put the old board in it starts to power cycle again and I have power. Is the new video board bad, I can't understand why the new board will not power cycle.

[PlainBill]

Re: Magnavox

Ok, I got he new video board today, I installed it and now I get nothing. No power cycling, no lights nothing. When I put the old board in it starts to power cycle again and I have power. Is the new video board bad, I can't understand why the new board will not power cycle.

Things to think about:

Did you check part number and revision level of the two boards?

Any damage on the replacement board?

Were all cables connected properly?

Did 5V get to the new board?

Did the signal from the remote or the front panel power button get to the board?

Did you buy it from a reputable seller?

With the original board, does the front panel light blink after the power supply shuts down?

PlainBill

[mav6759]

Re: Magnavox

Yes, I did brought the board from a guy that is a Tv repairmen for about 35 years. When I got the board in the mail the packaging was all torn where you could see the board. That the USPS for you. But anyway, I'm getting the 5v that I need at startup, wheich mean to tell me there is something simple going on. I changed every board I can think of in that tv. It has to be a bad wire, cap, resistor or something.

[mav6759]

Re: Magnavox

ok, now I have change every board that I thoiught that matter in this Tv, all the buffer boards, Y board, main power supply, X board, Z, board. The only boards that had not been changed was the two sub power boards and the Logic board. I can't say its a bad wire bcause, I'm gtting the 5v's needed through out the board. The Tv just won't stay on. Any Idea's

[PlainBill]

Re: Magnavox

ok, now I have change every board that I thoiught that matter in this Tv, all the buffer boards, Y board, main power supply, X board, Z, board. The only boards that had not been changed was the two sub power boards and the Logic board. I can't say its a bad wire bcause, I'm gtting the 5v's needed through out the board. The Tv just won't stay on. Any Idea's

Why should I give you any more ideas? I've already told you what the problem is, but you ignore me. This TV was easily repairable before you started screwing around with it. I have no idea if it is repairable now, but I am sure that the only way it could be repaired is if you turn it over to someone who either knows what he is doing, or possibly someone who is willing to listen to advice. I'm through wasting time with it.

PlainBill

[mav6759]

Re: Magnavox

Ok, first of all I have not been screwing with it and what you suggested that was wrong was not right. The Tv is still not working, The mistakes that I made was taking it to a Tv repair shop 3 times, and got 3 differents response. I exchanged what every the repair shops told me to change and they were wrong. I was told it was the Y board, X board, both buffer boards, the large power supply, and the 3 smaller sub power suppiles, I did change 2 of the power supplies, and the main board. I have changed all these boards after these so called tech's told me that they were the problem. So now Im back to square one. All three tech's have checked the main power supply and said it was good. I don't know what else to check. So to recap. The Y board, buffer boards, Z board, X board, Main power supply and 2 sub power supplies and all good. I'm getting the 5v at startup which is need, but the Tv still trys to power for about 3 sec, and shuts down

[smason]

Re: Magnavox

What is your day job? Are you a tow truck driver, a mortgage broker, or a bill collector?

Ok, now I know my next repair job, cleaning the Margarita off of my notebook screen and keyboard.

[PlainBill]

Re: Magnavox

Ok, now I know my next repair job, cleaning the Margarita off of my notebook screen and keyboard.

Sorry about that.

PlainBill

[ultramega1]

Re: Magnavox

ya gotta love simplicity!

[mav6759]

Re: Magnavox

OK, new update, I have changed just about every board in this TV. I even went out and brought the power supply repair kit off of ebay that everyone seem to have very good luck with. The only boards that I have not changed was the small buffer boards, the audio board and the screen itself. We exchanged parts from one Tv and put them into the same model, Y,Z, main power board, small power board, and 2 other boards hidden under this metal box. Each time we swaped out a board, the other Tv worked, which tells me the borads are good. I have no idea what wrong with this set. Two Question; Could either of the small buffer boards cause the Tv not to stay on; and how can you tell if it is the screen itself.

[PlainBill]

Re: Magnavox

OK, new update, I have changed just about every board in this TV. I even went out and brought the power supply repair kit off of ebay that everyone seem to have very good luck with. The only boards that I have not changed was the small buffer boards, the audio board and the screen itself. We exchanged parts from one Tv and put them into the same model, Y,Z, main power board, small power board, and 2 other boards hidden under this metal box. Each time we swaped out a board, the other Tv worked, which tells me the borads are good. I have no idea what wrong with this set. Two Question; Could either of the small buffer boards cause the Tv not to stay on; and how can you tell if it is the screen itself.

I don't know of any way to determine if the plasma panel itself is bad other than by hooking up a known good board.

If the X or Y buffers are bad they can cause a 'no display' problem. They MAY be able to cause the set to go into protection. The audio amplifier is certainly capable of causing the set to go into protection.

PlainBill

[mav6759]

Re: Sony KDE-42XS955

This is a update to my last update...I got a another Tv its a Sony KDE-42XS955. It has great picture and sound. The only problem is, there is a vertical line on the right side of the screen. It take up a small portion of the screen about 6 to 7 inches.. I took some pictures of it with my camera phone and I posted it below. When I called Sony, they told me to reset the Tv back to the factory setting. But the only way to do that is with the remote which the Tv did not come with one. But I don't think setting this Tv back to the factory settings will fix this problem...Does anyone know what could cause this. I think Sony was trying to tell me that the screen was to large or something like that.