About Henry A. McKelvey Expertise I have worked in the Electronics field for 25 years, and have been a Telecommunications Expert for 20 years. My Expertise has been in: Video, Audio, RF, Television, and Stereo. I have been in the Television repair business for 25 years and have repaired over 20,000 Televisions in that time. I was a manager of an Information Technology Training Team at The Verizon Advanced Services Group Center, and a Distinguished Member of Technical Staff at Verizon Laboratories. I am now working full time in the TV repair industry until I can find another full time job, I know what your question is: "why don't you just work full time in the TV repair industry permanently?" Well the answer to that is simple, due to the complexity and the DIY craze, TV repair work is at best a good way to make extra money, not to rely on it for your livelihood. A sad truth, but a truth nonetheless.
Experience 25 years as an Electronics Repair Technician, 20 years as a Telecommunications Expert, and I love Electronics.
Organizations The Society of Broadcast Engineers (SBE)
The International Society of Certified Electronics Technicians (ISCET)
Publications On-Line: http://www.fixya.com/users/shuttle83 (solutions to repair issues)
US Patent and Trade Office: (Copy and paste the link below)
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=0&f=S&l=50&TERM1=McKelvey&FIELD1=&co1=AND&TERM2=Verizon&FIELD2=&d=PG01
Education/Credentials University of Phoenix (MSCIS working on)
University of Phoenix (BSIT 2006)
World College CIE (BTEE 2006)
Cleveland Institute of Technology (ASEE 2006)
National Education Center (Diploma in Commputer and Network Technology 1989)
TESST Electronics School (Diploma in Electronics Engineering Technology 1985)
AG Bell Vocational High School (Diploma in Electronics Repair (Radio and Television Repair 1983)
Awards and Honors Society of Broadcast Engineers Membership (July 2006)
Special Technology Achievement & Recognition Award (STAR Award) August 2004 (ISO 9000 Certification VTO-SIT)
CWNP Certified Wireless Network Administrator (June 2004)
Special Technology Achievement & Recognition Award (STAR Award) September 2003 (MSN Project)
Special Technology Achievement & Recognition Award (STAR Award) November 2003 (Client CD and Registration Server Issue)
Network Management Certification (ICCP)(2002)
Data Communications Engineer Certification (Global Knowledge)(2002)
TCP/IP Network Analyst Certification (ICCP) (2002)
Winners Circle Award for Development of the DNOC Provisional training Team (2001)
FCC License General Radiotelephone without endorsement (1985)
FCC License General Radiotelephone with shipboard RADAR endorsement (1985)
Certified Electronics Technician Certificate (Electronic Communications)(1989)
Certified Electronics Technician Certificate (Consumer Electronics)(1985)
6 Patent Applications on file (do google search on "Henry A. McKelvey")
Past/Present Clients See http://www.fixya.com/users/shuttle83
http://www.google.com/search?hl=en&rlz=1T4DMUS_enUS243US243&q=%22Henry+A.+McKelvey%22+TV+Repair&aq=f&oq=&aqi=
I will try to provide as much info as I can without writing a book. I have a 20" Philips TV built in 1989. It was working perfectly until it suddenly shutdown, and burned about a one inch area of the board. Here are the numbers. The set is a Model # 20K151SB02. The chassis board reads E1A232D along the rear edge, with a barcode sticker next it reading 09152715. There is also a sticker on the regulator heatsink which says Chassis Model 20P1-01. The location of the burnt area is under the resistors R421 and the one next to it. I cannot read the second one, but they both have a common lead on the board. Both resistors got red hot, causing the burned area. The resistance value stripes on them has been burned away. They are located in between the T401 Full Power Transformer, and the Q420 regulator heatsink. They got so hot that they roasted capacitors C419 and C421. The large electrolytic capacitor C404 also got very warm during this occurance. I can get a new "factory defect" board for parts at a minimal cost that appears identical in the picture. It is listed as Part # E1A510F007. Hopefully the components are compatible. That is all the information I can provide. Please tell me what likely has happened, and where to concentrate my repairs. Thank you for your time !
ANSWER: Hello Scott,
From what you relayed, here is a possible scenario;
One of the high power transistors shorted causing an excessive current flow which R421 and the one next to it are in-line with. Q420 is suspect and should be checked along with the circuits R421 are attached to. You will need a schematic to guide you through the troubleshooting procedure. You are looking for a short circuited Transistor, or capacitor most likely. Now for all of those roasted components you are going to have to replace them, and check the circuitry they are connected to as part of assuring that nothing else is wrong with the TV.
Thank you very much for your prompt response. I suspected a regulator problem, but I wanted an experts confirmation before proceding so I wasn't going at it blindly. I have one more short query about this project. Is there any way you can tell by referencing the chassis board part numbers I provided, whether the donor board I can buy will provide me with usable replacement parts. If that information is not at your disposal, can you tell me the ohm value and wattage of the two burnt up resistors. I can read the value of the two roasted capacitors, which I believe are metal foil or film type. As for any transistors, I can cross reference them in my ECG catalog as long as they are not proprietary to Philips. I will also try to track down a good schematic, as the one inside the TV is useless. I don't know why they bother to put it in there. Thanks again for your time and expertise.
Best regards....Scott
Answer Hello Scott,
I got good news and bad news.
The good news is the service manual can help you with matching the chassis's parts, and getting part numbers and values.
