My set is 3 years old, i have a code 22 short protect circuit. The main board (center board) has burned resistors rk502-rk506. I replaced the burned resistors. I have removed and checked the following diode(s) D5K02, D5K03, EY501A, EY504B all ok. I have also removed and checked the following transistors Q5K00, Q5K01 also check out to be ok. I have checked the solder points at the 18 pin IC8C01 and IC8C02, appear to be in good shape. Set continues to click on then turn it self off. Continued code 22. Can you give me some insight where I should look next.
Thanks,
Sean
Does no one have any experience with this concern on code 22 or is this not a very common problem with this big screen television set? HELP pleeeeze.
Are you sure we are talking about the same model number. That is not the way Mitsubishi has the parts listed in the set. They start with a letter such a R then a number such as 5, then another number such as K, then another number such as 02. Do you have a service manual for this and are you working in the horizontal sweep circuit. That is where the series of the parts 5 seem to be?
Thanks for the reply Larry,
The model number on the back board is WS-55313 BUILD DATE OCTOBER 2003. I do have the schematics and service manual. I recheck those numbers, Sorry I transposed the resistor digits should be R5K02 thru R5K06. I replaced them as well as chceked the mentioned transistors and diodes. I have further checked all the fuses on the power board. I just replaced the IC8C01 and IC8C02 (STK394-250) circuits. I continue to have the same concern. When I attempt to power the set it clicks on then tick, tick, tick, tick then the set shuts off. Code 22 is still present. I believe maybe the CRT are shorted causing the concern, but I am not sure if thats where I should be looking at this point. And if the CRT'S are at fault where can I purchase them. Mitsubishi will only sell them to authorized distributors.
Thanks For some feed back, hope you can provide some insight
Larry,
Can you tell me what circuit the Horizontal Output Transistor is? (HOT)
Thanks Sean
It is in the same circuit your working on. It is a FET and not a transistor. Yoiu must replace it, as it cannot be checked without a FET checker.
Thanks Larry, Do you know what the circuit number is?
OK, after doing some more circuit analysis, I seen the resistors you are taking about, the R5K03 through R5K06. How did you see they were burnt? Were they charred? Or was it you could not get a reading on them? What value of resistor did you replace them with? The circuit you are working on is in the horizontal sweep circuit, but that circuit controls the focus. I have never seen those resistors you are talking about burn. The R5K03 is a 120K, the R5K04 is a 100k, the R5K05 is a 120k, and the R5K05 is a 100k. The horizontal output FET is the Q5A51.
The R5K02 1k 1/4 watt resistor was charred (blackened) . circuit board had black burn mark beneath it. R5K04 and R5K06 are 100k 1/2 watt resistors had a little black beneath them. the 120k checked out ok. I replaced the resistors with the same values. I have been unable to determine why they burned except they were visually burned.
Still have the code 22 short detecet circuit. When set is turned on, you here the initial clcik and the ticktick tick from the start up replays. Could it be the the HOT is not transferring control to start the set?
Looking at the scematics, it appears the short detect circuit monitors the -24 volt and +24 volt circuit, Should I be looking at that cicruit instead? or perhaps the start up circuit near the 24 volt supply? The pico fuses check out. (F9A04 and F9A05) Diode D9A60 and D9A61 after these pico fuses also check out ok. so it does not appear there is a short at the coil transformer.
Thanks Again Larry for any insight you may have.
Sean
Disconnect the convergence IC's and see if the set comes on. I know you said you replaced them. Also disconnect the audio amp from the circuit. You will need to see where the set is being loaded down.
removed the ic, the set still will not power up, i believe the audi amp is IC3E01.
Ok if it is not in the convergence circuit, replace the horizontal output and make sure you check the main focus circuit driver transistors as well. Use a light bulb, about 150 watt tyoe, across the main AC fuse. Let me know what happens.
larry which are the main focus transistors?
so far the hot mosfet check out ok, haven't yet put the bulb across the fuse, but need to check the main focus transitor, my the schematic doesn't reallt explai what parts east circuit on the board are and what it does?
The circuit you had the bad resistors in is the focus circuit. This is where experience comes into play. When you can look at certain circuits and know what they do.
Did you get the TV fixed? I have the same error code 22 for the same model TV, I bought the repair kit, replaced one bad pico fuse and the IC?s, but I still get the same error. I get the same clicks you described when I turn it on. The only difference now from before I change the IC?s and the pico is that now, the green light stays on, three seconds longer than before.
Any idea were to go from here?
Thanks.