Question about Sylvania SRT2232S 32" TV
Model is Actually a SRT2232X 32" TV (CRT). (I think the "X" is just a chassis color option). I am having a problem similar to other TV's. Last night there was a loud pop, then it shut off. I tried to turn it on again, and got an arcing (clicking) sound with a bright vertical signal centered on the CRT. It looked like an audio wave form, but running top to bottem, possibly retrace? Today, same symptoms. I purchased PDF Schematic online last night. Main Board = BL6509F01012-1 I discharged the CRT, removed main board and visually inspected it for obvious damage. Only R552 has slight discoloration on the PCB. Q552 may be damaged (not sure). I suspect Q571 (H-Out), Q572 (H-Drive), Q551 and/or Q552 (H-Control). Anyone had a similar problem with this PCB and fixed it?
Hello kd6aaj, You are on the right track, a vertical line usually means that you lost horizontal deflection which is supplied by the horizontal/High voltage section.The thing that puzzles me is that you did not lose high voltage. Let me explain. In modern TVs the horizontal section uses scan rectification or a process similar to a switching power supply to convert a lower voltage tapped off of the hoizontal/HV section to provide B+ for the rest of the television. So if you lose your Horizontal voltage you lose your B+ also. So you will never see the vertical line because you low voltage power supply if off also. Now I think your Q571 (H-Out), Q572 (H-Drive), Q551 and/or Q552 (H-Control) might be good. However check them anyway. I would also advise you to check your yoke transformer for an open or shorted winding. This would cause you to lose deflection without losing high voltage. You are definatly in the right section just add the deflection section to your scope of troubleshooting.
Posted on Sep 10, 2007
If you give me the URL to get to your schematics I'll be glad to help you.
I got it and I am going to give you some things to look for.
I am guessing that you do have a multiment and a oscilloscope which you will need to troubleshoot this.
First lets check for proper bias on the H-Drive transistor Q572 (Emitter(gnd)0v, Base .3v, Collector 22.0v. If these bias voltages are correct then Q572 is good, also check with the oscilloscope and see if a pulse waveform is present on the base of Q572 . if not (good bias and pluse) take Q572 out and test it with a transistor tester (there is another way by testing the reverse and forward bias of the diode junctions C-B, B-E, C-E, B-C, E-B, E-C but that would take too long to explain here properly), so the best way to test the transistor would be with a transistor checker.
Do the same for Q571 Emitter (gnd) 0v, base (not gnd) but still 0v but use Oscilloscope to look for waveform 8(WF8)which is your horizontal drive. Then I want you to check DY551 (delecetion yoke pin 1 for waveform 9 WF9 which should be your horizontal delection pulse. If the pulse is not there at deflection yoke pin one then the one cause of this would be Q571 being open (not shorted)This is unlikely but not impossible.
Let me know how these readings go and I'll be able to tell you more once I know whow these look.
Excuse the typos it's 3:01 am here and I need some sleep, remember let me know how those readings go. If you know how to do a ring test, do one on the Horizontal side of the deflection yoke to see if the yoke sustained any damage.
×
518 views
Usually answered in minutes!
If I post the pdf service manual on the internet, could you check it and point me in the right direction?
The manual is a little vague, but has a great section on changing a jumper in the remote to turn it into a service remote! Lists test points and measurements, too.
I have 2 Sylvania TV's, so I tested it out.
You can change "color convergance", "pincushion", and other settings that are not available in the normal menu!
I tried to upload it here, but no joy.
So, here is the url. I'll remove it after maybe 1 week.
http://www.qsl.net/kd6aaj/SYLVANIA_SRT22...
Thanks!
Replaced all H-Control transistors and the H-Output transistor.
Unfortunately I DON'T have access to an o-scope. So I went with the the cheaper items (compared to the fly-back transformer, a repair shop [ugh!], or a new TV [$$$$$$!]).
Anyhow, when I plug in the AC cord, High Voltages charges up (clicking noise and picture tube charging), then the relay shuts off. Still not working. :(
Pushing the power switch does the same thing if I leave the TV pluged in.
When I un-plug the TV from 110VAC, a fast clicking noise is heard (a faster, higher pitched sound than the turn-on clicking). I think it's just a bleeder resistor for the high-voltage capasitor.
So, either I spend more money on a flyback or other parts... OR save a couple of grand to get a new tv to replace the 32 inch CRT.
That would take what, a 54 inch flat-panel LCD to get the same amount of vertical size as my 32 inch TV? Not sure.
×