Which version of the 737 did you get. Look on the Service manual and the back of the unit for clues. It's important.
1.) Resistors on the Power supply get hot for a reason. HEAT DISSIPATION. It's NORMAL. The board gets cooked and turns brown, just like a roast in the oven. When you rebuild the power supply, install the resistors about 1/4" (6-7mm) above the board to allow for air flow.
2.) Pull the latest parts list here and POST IT for VETTING! Since it was made parts have been changed, been superceded, etc. One of us will make sure it's up to date and ok it for you.
3.)
GET THE MANUALS FOR IT...... Manuals
HERE ........Get the HIGHEST RESOLUTION you can. READ THEM AND STUDY THE SERVICE MANUAL.
4.) Related to #3. All parts used are referenced to a BOARD #. For Example the 2sd313's on the power supply board are;
AWR-057 Q1 2SD313 E or D
and
AWR-057 Q3 2sd313 E or D
Resistors and caps are listed the same way. This is to make sure everyone is working off the same sheet of music. The "RGB5" resistor on the Power supply board doesn't tell us anything other than it's on the POWER SUPPLY board. BUT due to the cooking of the board I would venture to say it's probably
AWR-057 R3 180ohm 5W RT5B 181K.
5.) Also related to 3 & 4. On the PIONEER FORUM PAGE is a sticky thread (meaning it stays in place at the top or near the top of the list) called PIONEER TUNING FORK MANUALS (or words to that effect). DOWNLOAD THESE and read / study them. These will give you insights to how Pioneer engineered and numbered the parts for identification. Also how they work.
6.)
MOST IMPORTANT. The instructions in the manual for setting the bias and offset are INCORRECT! See this thread
"Notice to ALL 737 / 7730 OWNERS......" for details on correct procedure.
7.) GO SLOW AND METHODICALLY! jumping all over the place is confusing to you and us. Start with one problem and FIX the UNIT 1st. When it's running acceptably, THEN start the rebuild. Do one board at a time, test. If ok, go to the next board. If not, troubleshoot and FIX before moving on. This is one of the biggest problems with new owners. They want their gear to be 1000% NOW! It don't work like that. It takes time, concentration and a LOT OF PATIENCE. Granted the 737 is fairly easy compared to a 1010 or one of the big beasts, but it's also too easy to screw it up. If you don't understand something ask the question here, and wait for an answer. As most of us "Colonials" are 4-8 hours behind you, it might take a while. Sit on your hands, until you get the answer. DO NOT UnWRAP any wire from pins. You CAN lift each board from the chassis without removing the wiring. It's somewhat brittle, so a wire may break at the wire. If so, just solder it back to the pin. Make slack in the wiring by opening up the hold down ties.
8.) There are a few upgrades that are now considered mandatory that PIONEER initially didn't put in, but later did. Suggest you read all of the 737 /7730 threads. The one that has the largest protection impact is a single diode. It's used to prevent back voltage to a transistor on the Protection Circuit board(AWM-025-C). When you shut the unit off, voltage flows back to the transistor(Q7) and over time causes the transistor to fail. Installing the diode keeps this from happening. Part is a 1n4004 to 4007 (whatever you have in hand of that series) attached to pins 9 and 10 of the protection circuit board(AWM-025C), with the banded side (Cathode) on pin 10.
The Dial Lamps are run off the 7.5vAC section of the transformer. Fused from F-1 (Fuse #1). Check the Fuse with a meter (out of circuit). Visual inspection isn't good enough. The Mode selector rotary switch is also involved to switch the function lamps. Also pull the lamps and check each one with a meter. This is a common problem with fuse lamps and long distance moves. They worked at one place and when at the new place don't work. If they don't meter out, just get new lamps.
The TIP41C is probably ok here. But I'd replace it with a KSC2073 (per the parts list).
The Cooking of the board is NORMAL with a high wattage resistor. It dissipates a lot of heat. Short of redesigning the whole board, all you can do is raising the resistor a bit above the board (outlined above).
Some pictures of the boards will help in determining how much "abuse" it's had.
EDIT: I didn't see the pictures at 1st. The pictures conform my guess on the resistor. Also with the lamps, they are most likely burnt out as the function lamps are working (same circuit). Pull, test and replace as necessary.
Larry
A real looker!
