Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
Sony TV KV32V36 powers off and back on
Sony KV32V36 TV, it is a 32" model with top keypad. Turns itself off and
back on. When comes back on always to "Video1" input, which is default input as I understand. Problem is intermittent. May work fine for a few months, or start doing it several times a day or even go crazy and switch it off and on few times at once. Was repaired 4 times by Sony without ever fixing the problem, TV is now almost 6 years old and was doing it ever since I bought it. No fault codes are stored in the processor, so out of 4 repairs Sony replaced top keypad 3 times. Repair tech. is saying that if it were a CRT or any other major component problem processor would have stored the error codes. Any ideas? Thanks in advance. |
#2
|
|||
|
|||
|
#3
|
|||
|
|||
|
#4
|
|||
|
|||
I have not worked on this model for a very long time. But, if you look
down the centre of the main board, I believe that there are a number of voltage regulators in a row that are heatsinked to the top frame, using a metal bar, or something like that. Re-solder all the pins on these. Also resolder very well, the leads of the horiz line drive transformer, that drives the HOT (horizontal output transistor). This is the small transformer after the horiz line drive pre-amp stage that is before the HOT. Because you say that the set is going back to Input 1, this means that something is doing a full reset. This means that the uPC is loosing its supply, and thus re-setting. If this set is properly turned off and back on again, it should come back to where it last was. In some models of the Sony, there is a separate standby supply for the uPC. In your model, I think that that the standby supply is part of the main power supply. If this is so, this means that something is putting the complete power supply in to protect, or it in itself is failing. Also do an ESR test on all the electrolytic capacitors in the power supply, the horizontal output stage, CRT board, and the vertical deflection amp. I've seen problems with these in all of these areas, especialy when these sets were getting old. This is what I can remember that I used to do with these sets. If it beyond this, then you will have a challenging job to find the fault. It is able to be found, but you will need a lot of experience, and the proper setup with the proper service information to find it. -- Jerry G. ====== "John Smith" wrote in message news:0_%1d.12683$yW6.1888@clgrps12... To reply by email Remove NOSPAM from email address Thanks "John Smith" wrote in message news:hz%1d.12682$yW6.576@clgrps12... Sony KV32V36 TV, it is a 32" model with top keypad. Turns itself off and back on. When comes back on always to "Video1" input, which is default input as I understand. Problem is intermittent. May work fine for a few months, or start doing it several times a day or even go crazy and switch it off and on few times at once. Was repaired 4 times by Sony without ever fixing the problem, TV is now almost 6 years old and was doing it ever since I bought it. No fault codes are stored in the processor, so out of 4 repairs Sony replaced top keypad 3 times. Repair tech. is saying that if it were a CRT or any other major component problem processor would have stored the error codes. Any ideas? Thanks in advance. |
#5
|
|||
|
|||
I have not worked on this model for a very long time. But, if you look
down the centre of the main board, I believe that there are a number of voltage regulators in a row that are heatsinked to the top frame, using a metal bar, or something like that. Re-solder all the pins on these. Also resolder very well, the leads of the horiz line drive transformer, that drives the HOT (horizontal output transistor). This is the small transformer after the horiz line drive pre-amp stage that is before the HOT. Because you say that the set is going back to Input 1, this means that something is doing a full reset. This means that the uPC is loosing its supply, and thus re-setting. If this set is properly turned off and back on again, it should come back to where it last was. In some models of the Sony, there is a separate standby supply for the uPC. In your model, I think that that the standby supply is part of the main power supply. If this is so, this means that something is putting the complete power supply in to protect, or it in itself is failing. Also do an ESR test on all the electrolytic capacitors in the power supply, the horizontal output stage, CRT board, and the vertical deflection amp. I've seen problems with these in all of these areas, especialy when these sets were getting old. This is what I can remember that I used to do with these sets. If it beyond this, then you will have a challenging job to find the fault. It is able to be found, but you will need a lot of experience, and the proper setup with the proper service information to find it. -- Jerry G. ====== "John Smith" wrote in message news:0_%1d.12683$yW6.1888@clgrps12... To reply by email Remove NOSPAM from email address Thanks "John Smith" wrote in message news:hz%1d.12682$yW6.576@clgrps12... Sony KV32V36 TV, it is a 32" model with top keypad. Turns itself off and back on. When comes back on always to "Video1" input, which is default input as I understand. Problem is intermittent. May work fine for a few months, or start doing it several times a day or even go crazy and switch it off and on few times at once. Was repaired 4 times by Sony without ever fixing the problem, TV is now almost 6 years old and was doing it ever since I bought it. No fault codes are stored in the processor, so out of 4 repairs Sony replaced top keypad 3 times. Repair tech. is saying that if it were a CRT or any other major component problem processor would have stored the error codes. Any ideas? Thanks in advance. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|